XYLANASE VARIANTS AND POLYNUCLEOTIDES CODING THEM

Description

Reference to a Sequence Listing

[0001] This application contains a Sequence Listing in computer readable form..Background of the Invention Field of the Invention

[0002] The present invention relates to xylanase variants, polynucleotides encoding the variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; compositions and animal feed comprising the xylanase variants, and methods of using the variants.Description of the Related Art

[0003] Xylans are hemicelluloses found in all land plants (Popper and Tuohy, 2010, Plant Physiology 153: 373-383). They are especially abundant in secondary cell walls and xylem cells. In grasses, with type II cell walls, glucurono arabinoxylans are the main hemicellulose and are present as soluble or insoluble dietary fiber in many grass based food and feed products.

[0004] Plant xylans have a β-1,4-linked xylopyranose backbone that can be substituted at the O2 or O3 position with arabinose, glucuronic acid and acetic acid in a species and tissue specific manner. The starch-rich seeds of the sub-family Panicoideae with economically important species such as corn, sorghum, rice and millet have special types of highly substituted xylans in their cell walls. Compared to wheat flour, wherein over 60% of the xylosyl units in the arabinoxylan backbone are unsubstituted. In corn kernel xylan, the corresponding percentage of unsubstituted backbone xylosyls is 20-30%, and in sorghum it is 35-40% (Huismann et al., 2000, Carbohydrate Polymers 42: 269-279). Furthermore, in corn and sorghum the xylan side chains can be longer than a single arabinose or glucuronic acid substitution which is common in other xylans. This added side chain complexity is often due to L- and D-galactose and D-xylose sugars bound to the side chain arabinose or glucuronic acid. About every tenth arabinose in corn kernel xylan is also esterified with a ferulic acid and about every fourth xylose carries an acetylation (Agger et al., 2010, J. Agric. Food Chem. 58: 6141-6148). All of these factors combined make the highly substituted xylans in corn and sorghum resistant to degradation by traditional xylanases.

[0005] The known enzymes responsible for the hydrolysis of the xylan backbone are classified into enzyme families based on sequence similarity (cazy.org). The enzymes with mainly endo-xylanase activity have previously been described in Glycoside hydrolase family (GH) 5, 8, 10, 11, 30 and 98. The enzymes within a family share some characteristics such as 3D fold and they usually share the same reaction mechanism. Some GH families have narrow or mono-specific substrate specificities while other families have broad substrate specificities.

[0006] Commercially available GH10 and GH11 xylanases are often used to break down the xylose backbone of arabinoxylan. In animal feed this results in a degradation of the cereal cell wall with a subsequent improvement in nutrient release (starch and protein) encapsulated within the cells. Degradation of xylan also results in the formation of xylose oligomers that may be utilised for hind gut fermentation and therefore can help an animal to obtain more digestible energy. However, such xylanases are sensitive to side chain steric hindrance and whilst they are effective at degrading arabinoxylan from wheat, they are not very effective on the xylan found in the seeds of Poaceae species, such as corn or sorghum.

[0007] EP 2 298 904 discloses a number of wild-type xylanases and their expression, said xylanases having endo-1,4-beta-xylanase activity. EP 2 298 904 discloses that at least some of the xylanases have activity on wheat arabinoxylan. EP 2 298 904 demonstrated the use of selected wild-type xylanases in pre-treating paper pulp and discloses the potential use of the xylanases in other industries including animal feed. One of the wild-type xylanases of EP 2 298 904, isolated from an undisclosed environmental sample, is a suitable embodiment of SEQ ID NO: 1. WP 024573168 discloses a wild-type glucuroxylanase from Bacillus subtilis having a sequence identity related to SEQ ID NO: 1. WP 076170814 discloses a wild-type glucuroxylanase from Paenibacillus rhizosphaerae having a sequence identity related to SEQ ID NO: 1.

[0008] Corn is used around the world in animal feed and thus there is a need to discover new polypeptides having xylanase activity that are capable of breaking down the highly branched xylan backbone in the cell wall in order to release more xylose and other nutrients which are trapped inside the cell wall.

[0009] The present invention provides xylanase variants with improved properties compared to its parent.Summary of the Invention

[0010] The present invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and wherein the position corresponds to the position of SEQ ID NO: 1, wherein the variant has improved thermostability compared to the SEQ ID NO: 1.

[0011] The invention is further directed to a polynucleotide encoding the xylanase variant of the invention, to a recombinant host cell comprising said polynucleotide operably linked to one or more control sequences that direct the production of the polypeptide, and to a method of producing the xylanase variant of the invention, comprising cultivating said recombinant host cell under conditions conducive for production of the polypeptide; and recovering the polypeptide.

[0012] The invention is further directed to an animal feed additive comprising the xylanase variant of the invention and one or more components selected from the group consisting of: one or more vitamins; one or more minerals; one or more amino acids; one or more phytogenics; one or more prebiotics; one or more organic acids; and one or more other ingredients is disclosed. The invention is further directed to an animal feed comprising the xylanase variant of the invention and plant based material is disclosed.

[0013] The invention is further directed to a granule comprising the xylanase variant of the invention and a formulating agent, wherein the granule comprises a core particle and one or more coatings. The invention is further directed to a a liquid formulation comprising the xylanase variant of the invention, wherein the xylanase variant is dosed between 0.01% to 25% w / w of liquid formulation.

[0014] The invention is further directed to use of the xylanase variant, the granule, the animal feed additive, the liquid formulation or the animal feed of the invention in animal feed; in animal feed additives; in the preparation of a composition for use in animal feed; for improving the nutritional value of an animal feed; for increasing digestibility of an animal feed; for improving one or more performance parameters in an animal; and for solubilizing xylan from plant based material for releasing starch from plant based material.

[0015] The invention is further directed to a a process of producing a fermentation product, comprising the following steps: (a) saccharifying a starch-containing material at a temperature below the initial gelatinization temperature with an alpha-amylase, a glucoamylase, and a xylanase variant of the invention; and (b) fermenting using a fermentation organism.

[0016] The invention is further directed to a method for preparing a dough or a baked product prepared from the dough which method comprises incorporating into the dough a xylanase variant of the invention.Overview of Sequence Listing

[0017] SEQ ID NO: 1 is the amino acid sequence of a mature GH30 xylanase from Bacillus subtilis. SEQ ID NO: 2 is the amino acid sequence of a mature GH30 xylanase from Bacillus amyloliquefaciens. SEQ ID NO: 3 is the amino acid sequence of a mature GH30 xylanase from Bacillus licheniformis. SEQ ID NO: 4 is the amino acid sequence of a mature GH30 xylanase from Bacillus subtilis. SEQ ID NO: 5 is the amino acid sequence of a mature GH30 xylanase from Paenibacillus pabuli. SEQ ID NO: 6 is the amino acid sequence of a mature GH30 xylanase from Bacillus amyloliquefaciens HB-26. Definitions

[0018] Xylanase: The term "xylanase" means a glucuronoarabinoxylan endo-1,4-beta-xylanase (E.C. 3.2.1.136) that catalyses the endohydrolysis of 1,4-beta-D-xylosyl links in some glucuronoarabinoxylans. Xylanase activity can be determined with 0.2% AZCL-glucuronoxylan as substrate in 0.01% TRITON ®< X-100 and 200 mM sodium phosphate pH 6 at 37°C. One unit of xylanase activity is defined as 1.0 µmole of azurine produced per minute at 37°C, pH 6 from 0.2% AZCL-glucuronoxylan as substrate in 200 mM sodium phosphate pH 6.

[0019] Allelic variant: The term "allelic variant" means any of two or more alternative forms of a gene occupying the same chromosomal locus. Allelic variation arises naturally through mutation, and may result in polymorphism within populations. Gene mutations can be silent (no change in the encoded polypeptide) or may encode polypeptides having altered amino acid sequences. An allelic variant of a polypeptide is a polypeptide encoded by an allelic variant of a gene.

[0020] Animal: The term "animal" refers to all animals except humans. Examples of animals are non-ruminants, and ruminants. Ruminant animals include, for example, animals such as sheep, goats, cattle, e.g., beef cattle, cows, and young calves, deer, yank, camel, llama and kangaroo. Non-ruminant animals include mono-gastric animals, e.g., pigs or swine (including, but not limited to, piglets, growing pigs, and sows); poultry such as turkeys, ducks and chicken (including but not limited to broiler chicks, layers); horses (including but not limited to hotbloods, coldbloods and warm bloods), young calves; fish (including but not limited to amberjack, arapaima, barb, bass, bluefish, bocachico, bream, bullhead, cachama, carp, catfish, catla, chanos, char, cichlid, cobia, cod, crappie, dorada, drum, eel, goby, goldfish, gourami, grouper, guapote, halibut, java, labeo, lai, loach, mackerel, milkfish, mojarra, mudfish, mullet, paco, pearlspot, pejerrey, perch, pike, pompano, roach, salmon, sampa, sauger, sea bass, seabream, shiner, sleeper, snakehead, snapper, snook, sole, spinefoot, sturgeon, sunfish, sweetfish, tench, terror, tilapia, trout, tuna, turbot, vendace, walleye and whitefish); and crustaceans (including but not limited to shrimps and prawns).

[0021] Animal feed: The term "animal feed" refers to any compound, preparation, or mixture suitable for, or intended for intake by an animal. Animal feed for a mono-gastric animal typically comprises concentrates as well as vitamins, minerals, enzymes, direct fed microbial, amino acids and / or other feed ingredients (such as in a premix) whereas animal feed for ruminants generally comprises forage (including roughage and silage) and may further comprise concentrates as well as vitamins, minerals, enzymes direct fed microbial, amino acid and / or other feed ingredients (such as in a premix).

[0022] Arabinoxylan-containing material: The term "Arabinoxylan-containing material" means any material containing arabinoxylan. Arabinoxylan is a hemicellulose found in both the primary and secondary cell walls of plants, including woods and cereal grains, consisting of copolymers of two pentose sugars, arabinose and xylose. The arabinoxylan chain contains a large number of 1,4-linked xylose units. Many xylose units are substituted with 2-, 3- or 2,3-substituted arabinose residues.

[0023] Examples of arabinoxylan-containing material are forage, roughage, seeds and grains (either whole or prepared by crushing, milling, etc from, e.g., corn, oats, rye, barley, wheat), trees or hard woods (such as poplar, willow, eucalyptus, palm, maple, birch), bamboo, herbaceous and / or woody energy crops, agricultural food and feed crops, animal feed products, cassava peels, cocoa pods, sugar cane, sugar beet, locust bean pulp, vegetable or fruit pomaces, wood waste, bark, shavings, sawdust, wood pulp, pulping liquor, waste paper, cardboard, construction and demolition wood waste, industrial or municipal waste water solids or sludge, manure, byproduct from brewing and / or fermentation processes, wet distillers grain, dried distillers grain, spent grain, vinasse and bagasse.

[0024] Forage as defined herein also includes roughage. Forage is fresh plant material such as hay and silage from forage plants, grass and other forage plants, grass and other forage plants, seaweed, sprouted grains and legumes, or any combination thereof. Examples of forage plants are Alfalfa (Lucerne), birdsfoot trefoil, brassica (e.g., kale, rapeseed (canola), rutabaga (swede), turnip), clover (e.g., alsike clover, red clover, subterranean clover, white clover), grass (e.g., Bermuda grass, brome, false oat grass, fescue, heath grass, meadow grasses, miscanthus, orchard grass, ryegrass, switchgrass, Timothy-grass), corn (maize), hemp, millet, barley, oats, rye, sorghum, soybeans and wheat and vegetables such as beets. Crops suitable for ensilage are the ordinary grasses, clovers, alfalfa, vetches, oats, rye and maize. Forage further includes crop residues from grain production (such as corn stover; straw from wheat, barley, oat, rye and other grains); residues from vegetables like beet tops; residues from oilseed production like stems and leaves form soy beans, rapeseed and other legumes; and fractions from the refining of grains for animal or human consumption or from fuel production or other industries.

[0025] Roughage is generally dry plant material with high levels of fiber, such as fiber, bran, husks from seeds and grains and crop residues (such as stover, copra, straw, chaff, sugar beet waste).

[0026] Preferred sources of arabinoxylan-containing materials are forage, roughage, seeds and grains, sugar cane, sugar beet and wood pulp.

[0027] Body Weight Gain: The term "body weight gain" means an increase in live weight of an animal during a given period of time, e.g., the increase in weight from day 1 to day 21.

[0028] cDNA: The term "cDNA" means a DNA molecule that can be prepared by reverse transcription from a mature, spliced, mRNA molecule obtained from a eukaryotic or prokaryotic cell. cDNA lacks intron sequences that may be present in the corresponding genomic DNA. The initial, primary RNA transcript is a precursor to mRNA that is processed through a series of steps, including splicing, before appearing as mature spliced mRNA.

[0029] Coding sequence: The term "coding sequence" means a polynucleotide, which directly specifies the amino acid sequence of a variant. The boundaries of the coding sequence are generally determined by an open reading frame, which begins with a start codon such as ATG, GTG or TTG and ends with a stop codon such as TAA, TAG, or TGA. The coding sequence may be a genomic DNA, cDNA, synthetic DNA, or a combination thereof.

[0030] Control sequences: The term "control sequences" means nucleic acid sequences necessary for expression of a polynucleotide encoding a variant of the present invention. Each control sequence may be native (i.e., from the same gene) or foreign (i.e., from a different gene) to the polynucleotide encoding the variant or native or foreign to each other. Such control sequences include, but are not limited to, a leader, polyadenylation sequence, propeptide sequence, promoter, signal peptide sequence, and transcription terminator. At a minimum, the control sequences include a promoter, and transcriptional and translational stop signals. The control sequences may be provided with linkers for the purpose of introducing specific restriction sites facilitating ligation of the control sequences with the coding region of the polynucleotide encoding a variant.

[0031] Expression: The term "expression" includes any step involved in the production of a variant including, but not limited to, transcription, post-transcriptional modification, translation, post-translational modification, and secretion.

[0032] Expression vector: The term "expression vector" means a linear or circular DNA molecule that comprises a polynucleotide encoding a variant and is operably linked to control sequences that provide for its expression.

[0033] Feed Conversion Ratio: The term "feed conversion ratio" the amount of feed fed to an animal to increase the weight of the animal by a specified amount. An improved feed conversion ratio means a lower feed conversion ratio. By "lower feed conversion ratio" or "improved feed conversion ratio" it is meant that the use of a feed additive composition in feed results in a lower amount of feed being required to be fed to an animal to increase the weight of the animal by a specified amount compared to the amount of feed required to increase the weight of the animal by the same amount when the feed does not comprise said feed additive composition.

[0034] Feed efficiency: The term "feed efficiency" means the amount of weight gain per unit of feed when the animal is fed ad-libitum or a specified amount of food during a period of time. By "increased feed efficiency" it is meant that the use of a feed additive composition according the present invention in feed results in an increased weight gain per unit of feed intake compared with an animal fed without said feed additive composition being present.

[0035] Fragment: The term "fragment" means a polypeptide having one or more (e.g., several) amino acids absent from the amino and / or carboxyl terminus of a mature polypeptide; wherein the fragment has xylanase activity. In one aspect, a fragment comprises at least 330 amino acid residues, at least 350 amino acid residues, or at least 370 amino acid residues.

[0036] In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 1, at least 350 amino acid residues of SEQ ID NO: 1, or at least 370 amino acid residues of SEQ ID NO: 1. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 2, at least 350 amino acid residues of SEQ ID NO: 2, or at least 370 amino acid residues of SEQ ID NO: 2. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 3, at least 350 amino acid residues of SEQ ID NO: 3, or at least 370 amino acid residues of SEQ ID NO: 3. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 4, at least 350 amino acid residues of SEQ ID NO: 4, or at least 370 amino acid residues of SEQ ID NO: 4. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 5, at least 350 amino acid residues of SEQ ID NO: 5, or at least 370 amino acid residues of SEQ ID NO: 5. In one aspect, a fragment comprises at least 330 amino acid residues of SEQ ID NO: 6, at least 350 amino acid residues of SEQ ID NO: 6, or at least 370 amino acid residues of SEQ ID NO: 6.

[0037] Highly branched xylan: The term "highly branched xylan" means that more than 50% of xylosyl units in the arabinoxylan backbone are substituted. This is preferably calculated from linkage analysis as performed in Huismann et al. Carbohydrate Polymers, 2000, 42:269-279.

[0038] Host cell: The term "host cell" means any cell type that is susceptible to transformation, transfection, transduction, or the like with a nucleic acid construct or expression vector comprising a polynucleotide of the present invention. The term "host cell" encompasses any progeny of a parent cell that is not identical to the parent cell due to mutations that occur during replication.

[0039] Improved property: The term "improved property" means a characteristic associated with a variant that is improved compared to the parent. Such improved properties include, but are not limited to, catalytic efficiency, catalytic rate, chemical stability, oxidation stability, pH activity, pH stability, specific activity, stability under storage conditions, substrate binding, substrate cleavage, substrate specificity, substrate stability, surface properties, thermal activity, and thermostability. In an embodiment, the improved property is improved thermostability, and thermostability may be determined as described in Example 2 herein.

[0040] Isolated: The term "isolated" means a substance in a form or environment which does not occur in nature. Non-limiting examples of isolated substances include (1) any non-naturally occurring substance, (2) any substance including, but not limited to, any enzyme, variant, nucleic acid, protein, peptide or cofactor, that is at least partially removed from one or more or all of the naturally occurring constituents with which it is associated in nature; (3) any substance modified by the hand of man relative to that substance found in nature; or (4) any substance modified by increasing the amount of the substance relative to other components with which it is naturally associated (e.g., multiple copies of a gene encoding the substance; use of a stronger promoter than the promoter naturally associated with the gene encoding the substance). An isolated substance may be present in a fermentation broth sample.

[0041] Mature polypeptide: The term "mature polypeptide" means a polypeptide in its final form following translation and any post-translational modifications, such as N-terminal processing, C-terminal truncation, glycosylation, phosphorylation, etc.

[0042] In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 1. In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 2. In one aspect, the mature polypeptide is amino acids 1 to 392 of SEQ ID NO: 3. In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 4. In one aspect, the mature polypeptide is amino acids 1 to 393 of SEQ ID NO: 5. In one aspect, the mature polypeptide is amino acids 1 to 391 of SEQ ID NO: 6.

[0043] It is known in the art that a host cell may produce a mixture of two of more different mature polypeptides (i.e., with a different C-terminal and / or N-terminal amino acid) expressed by the same polynucleotide. It is also known in the art that different host cells process polypeptides differently, and thus, one host cell expressing a polynucleotide may produce a different mature polypeptide (e.g., having a different C-terminal and / or N-terminal amino acid) as compared to another host cell expressing the same polynucleotide.

[0044] Mature polypeptide coding sequence: The term "mature polypeptide coding sequence" means a polynucleotide that encodes a mature polypeptide having xylanase activity.

[0045] Mutant: The term "mutant" means a polynucleotide encoding a variant.

[0046] Nucleic acid construct: The term "nucleic acid construct" means a nucleic acid molecule, either single- or double-stranded, which is isolated from a naturally occurring gene or is modified to contain segments of nucleic acids in a manner that would not otherwise exist in nature or which is synthetic, which comprises one or more control sequences.

[0047] Nutrient Digestibility: The term "nutrient digestibility" means the fraction of a nutrient that disappears from the gastro-intestinal tract or a specified segment of the gastro-intestinal tract, e.g., the small intestine. Nutrient digestibility may be measured as the difference between what is administered to the subject and what. comes out in the faeces of the subject, or between what is administered to the subject and what remains in the digesta on a specified segment of the gastro intestinal tract, e.g., the ileum.

[0048] Nutrient digestibility as used herein may be measured by the difference between the intake of a nutrient and the excreted nutrient by means of the total collection of excreta during a period of time; or with the use of an inert marker that is not absorbed by the animal, and allows the researcher calculating the amount of nutrient that disappeared in the entire gastro-intestinal tract or a segment of the gastro-intestinal tract. Such an inert marker may be titanium dioxide, chromic oxide or acid insoluble ash. Digestibility may be expressed as a percentage of the nutrient in the feed, or as mass units of digestible nutrient per mass units of nutrient in the feed. Nutrient digestibility as used herein encompasses starch digestibility, fat digestibility, protein digestibility, and amino acid digestibility.

[0049] Energy digestibility as used herein means the gross energy of the feed consumed minus the gross energy of the faeces or the gross energy of the feed consumed minus the gross energy of the remaining digesta on a specified segment of the gastro-intestinal tract of the animal, e.g., the ileum. Metabolizable energy as used herein refers to apparent metabolizable energy and means the gross energy of the feed consumed minus the gross energy contained in the faeces, urine, and gaseous products of digestion. Energy digestibility and metabolizable energy may be measured as the difference between the intake of gross energy and the gross energy excreted in the faeces or the digesta present in specified segment of the gastro-intestinal tract using the same methods to measure the digestibility of nutrients, with appropriate corrections for nitrogen excretion to calculate metabolizable energy of feed.

[0050] Operably linked: The term "operably linked" means a configuration in which a control sequence is placed at an appropriate position relative to the coding sequence of a polynucleotide such that the control sequence directs expression of the coding sequence.

[0051] Parent or parent xylanase: The term "parent" or "parent xylanase" means a xylanase to which a substitution is made to produce the xylanase variants of the present invention. The parent may be a naturally occurring (wild-type) polypeptide or a variant or fragment thereof.

[0052] Percentage solubilized xylan: The term "percentage solubilized xylan" means the amount of xylose measured in the supernatant after incubation with an enzyme compared to the total amount of xylose present in the substrate before the incubation with the enzyme. For the purpose of the present invention, the percentage solubilized xylan may be calculated using defatted destarched maize (DFDSM) as substrate. DFDSM is prepared according to 'Preparation of Defatted Destarched Maize (DFDSM)' in the experimental section.

[0053] The percentage solubilized xylan from defatted destarched maize (DFDSM) may be determined using the reaction conditions 20 µg enzyme / g DFDSM and incubation at 40°C, pH 5 for 2.5 hours as described in the 'Xylose solubilization assay' herein. Thus the term 'is performed under the reaction conditions 20 µg xylanase variant per gram defatted destarched maize (DFDSM) and incubation at 40°C, pH 5 for 2.5 hours' is to be understood that the percentage solubilised xylan is calculated as described in the 'Xylose solubilization assay' herein.

[0054] In a more detailed embodiment, 2% (w / w) DFDSM suspension was prepared in 100 mM sodium acetate, 5 mM CaCl 2 , pH 5 and allowed to hydrate for 30 min at room temperature under gently stirring. After hydration, 200 µl substrate suspension was pipetted into a 96 well plate and mixed with 20 µl enzyme solution to obtain a final enzyme concentration of 20 PPM relative to substrate (20 µg enzyme / g substrate). The enzyme / substrate mixtures were left for hydrolysis in 2.5 h at 40°C under gently agitation (500 RPM) in a plate incubator. After enzymatic hydrolysis, the enzyme / substrate plates were centrifuged for 10 min at 3000 RPM and 50 µl supernatant was mixed with 100 µl 1.6 M HCl and transferred to 300 µl PCR tubes and left for acid hydrolysis for 40 min at 90°C in a PCR machine. Samples were neutralized with 125 µl 1.4 M NaOH after acid hydrolysis and loaded on the HPAE-PAD for mono-saccharide analysis.

[0055] Sequence identity: The relatedness between two amino acid sequences or between two nucleotide sequences is described by the parameter "sequence identity".

[0056] For purposes of the present invention, the sequence identity between two amino acid sequences is determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970, J. Mol. Biol. 48: 443-453) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000, Trends Genet. 16: 276-277), e.g., version 5.0.0 or later. The parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EBLOSUM62 (EMBOSS version of BLOSUM62) substitution matrix. The output of Needle labeled "longest identity" (obtained using the -nobrief option) is used as the percent identity and is calculated as follows:(Identical Residues x 100) / (Length of Alignment - Total Number of Gaps in Alignment)

[0057] For purposes of the present invention, the sequence identity between two deoxyribonucleotide sequences is determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970, supra) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000, supra), e.g., version 5.0.0 or later. The parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EDNAFULL (EMBOSS version of NCBI NUC4.4) substitution matrix. The output of Needle labeled "longest identity" (obtained using the -nobrief option) is used as the percent identity and is calculated as follows:

[0058] Variant: The term "variant" means a polypeptide having xylanase activity comprising an alteration, i.e., a substitution, insertion, and / or deletion, at one or more (e.g., several) positions. A substitution means replacement of the amino acid occupying a position with a different amino acid; a deletion means removal of the amino acid occupying a position; and an insertion means adding an amino acid adjacent to and immediately following the amino acid occupying a position. The variants of the present invention have at least 20%, e.g., at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 100% of the xylanase activity of the polypeptide of SEQ ID NO: 1.

[0059] Wild-type xylanase: The term "wild-type" xylanase means a xylanase expressed by a naturally occurring microorganism, such as a bacterium, yeast, or filamentous fungus found in nature.Conventions for Designation of Variants

[0060] For purposes of the present invention, SEQ ID NO: 1 is used to determine the corresponding amino acid residue in another xylanase. The amino acid sequence of another xylanase is aligned with SEQ ID NO: 1, and based on the alignment, the amino acid position number corresponding to any amino acid residue in SEQ ID NO: 1 is determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970, J. Mol. Biol. 48: 443-453) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000, Trends Genet. 16: 276-277), e.g., version 5.0.0 or later. The parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EBLOSUM62 (EMBOSS version of BLOSUM62) substitution matrix.

[0061] Identification of the corresponding amino acid residue in another xylanase can be determined by an alignment of multiple polypeptide sequences using several computer programs including, but not limited to, MUSCLE (multiple sequence comparison by log-expectation; version 3.5 or later; Edgar, 2004, Nucleic Acids Research 32: 1792-1794), MAFFT (version 6.857 or later; Katoh and Kuma, 2002, Nucleic Acids Research 30: 3059-3066; Katoh et al., 2005, Nucleic Acids Research 33: 511-518; Katoh and Toh, 2007, Bioinformatics 23: 372-374; Katoh et al., 2009, Methods in Molecular Biology 537: 39-64; Katoh and Toh, 2010, Bioinformatics 26: 1899-1900), and EMBOSS EMMA employing ClustalW (1.83 or later; Thompson et al., 1994, Nucleic Acids Research 22: 4673-4680), using their respective default parameters.

[0062] When the other enzyme has diverged from the polypeptide of SEQ ID NO: 1 such that traditional sequence-based comparison fails to detect their relationship (Lindahl and Elofsson, 2000, J. Mol. Biol. 295: 613-615), other pairwise sequence comparison algorithms can be used. Greater sensitivity in sequence-based searching can be attained using search programs that utilize probabilistic representations of polypeptide families (profiles) to search databases. For example, the PSI-BLAST program generates profiles through an iterative database search process and is capable of detecting remote homologs (Atschul et al., 1997, Nucleic Acids Res. 25: 3389-3402). Even greater sensitivity can be achieved if the family or superfamily for the polypeptide has one or more representatives in the protein structure databases. Programs such as GenTHREADER (Jones, 1999, J. Mol. Biol. 287: 797-815; McGuffin and Jones, 2003, Bioinformatics 19: 874-881) utilize information from a variety of sources (PSI-BLAST, secondary structure prediction, structural alignment profiles, and solvation potentials) as input to a neural network that predicts the structural fold for a query sequence. Similarly, the method of Gough et al., 2000, J. Mol. Biol. 313: 903-919, can be used to align a sequence of unknown structure with the superfamily models present in the SCOP database. These alignments can in turn be used to generate homology models for the polypeptide, and such models can be assessed for accuracy using a variety of tools developed for that purpose.

[0063] For proteins of known structure, several tools and resources are available for retrieving and generating structural alignments. For example the SCOP superfamilies of proteins have been structurally aligned, and those alignments are accessible and downloadable. Two or more protein structures can be aligned using a variety of algorithms such as the distance alignment matrix (Holm and Sander, 1998, Proteins 33: 88-96) or combinatorial extension (Shindyalov and Bourne, 1998, Protein Engineering 11: 739-747), and implementation of these algorithms can additionally be utilized to query structure databases with a structure of interest in order to discover possible structural homologs (e.g., Holm and Park, 2000, Bioinformatics 16: 566-567).

[0064] In describing the variants of the present invention, the nomenclature described below is adapted for ease of reference. The accepted IUPAC single letter or three letter amino acid abbreviation is employed.

[0065] Substitutions. For an amino acid substitution, the following nomenclature is used: Original amino acid, position, substituted amino acid. Accordingly, the substitution of threonine at position 226 with alanine is designated as "Thr226Ala" or "T226A". Multiple mutations are separated by addition marks ("+"), e.g., "Gly205Arg + Ser411Phe" or "G205R + S411F", representing substitutions at positions 205 and 411 of glycine (G) with arginine (R) and serine (S) with phenylalanine (F), respectively.

[0066] Deletions. For an amino acid deletion, the following nomenclature is used: Original amino acid, position, *. Accordingly, the deletion of glycine at position 195 is designated as "Gly195*" or "G195*". Multiple deletions are separated by addition marks ("+"), e.g., "Gly195* + Ser411*" or "G195* + S411*".

[0067] Insertions. For an amino acid insertion, the following nomenclature is used: Original amino acid, position, original amino acid, inserted amino acid. Accordingly the insertion of lysine after glycine at position 195 is designated "Gly195GlyLys" or "G195GK". An insertion of multiple amino acids is designated [Original amino acid, position, original amino acid, inserted amino acid #1, inserted amino acid #2; etc.]. For example, the insertion of lysine and alanine after glycine at position 195 is indicated as "Gly195GlyLysAla" or "G195GKA".

[0068] In such cases the inserted amino acid residue(s) are numbered by the addition of lower case letters to the position number of the amino acid residue preceding the inserted amino acid residue(s). In the above example, the sequence would thus be: Parent:Variant:195195 195a 195bGG - K - A

[0069] Multiple alterations. Variants comprising multiple alterations are separated by a plus sign ("+"), e.g., "Arg170Tyr+Gly195Glu" or "R170Y+G195E" representing a substitution of arginine and glycine at positions 170 and 195 with tyrosine and glutamic acid, respectively.

[0070] Different alterations. Where different alterations can be introduced at a position, the different alterations are separated by a comma, e.g., "Arg170Tyr,Glu" represents a substitution of arginine at position 170 with tyrosine or glutamic acid. Thus, "Tyr167Gly,Ala + Arg170Gly,Ala" designates the following variants: "Tyr167Gly+Arg170Gly", "Tyr167Gly+Arg170Ala", "Tyr167Ala+Arg170Gly", and "Tyr167Ala+Arg170Ala".Detailed Description of the Invention

[0071] The invention relates to xylanase variants having one or more substitutions having an improved property, such as improved thermostability.Preparation of Variants

[0072] In a first aspect, the invention relates to a variant having xylanase activity. Thus, the invention relates to a method for obtaining a xylanase variant wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and wherein the position corresponds to the position of SEQ ID NO: 1, wherein the variant has improved thermostability compared to the SEQ ID NO: 1.In one embodiment, the xylanase variant has improved thermostability relative to the parent xylanase SEQ ID NO: 1, of at least 0.1°C, at least 0.5°C, at least 1.0°C, at least 1.5°C, at least 2.0°C, at least 2.5°C, at least 3.0°C, at least 3.5°C or at least 4.0°C.

[0073] In one embodiment, the xylanase variant has at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1.

[0074] In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus Bacillus or Paenibacillus, or even more preferably from the taxonomic species Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis or Paenibacillus pabuli. In one embodiment, the parent xylanase has at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1 and is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus Bacillus or Paenibacillus, or even more preferably from the taxonomic species Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis or Paenibacillus pabuli. In one embodiment, the xylanase is a GH30 subfamily 8 xylanase (herein referred to as GH30_8 xylanases).

[0075] The parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and / or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids.

[0076] In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W and Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position.

[0077] In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions.

[0078] In one embodiment, the xylanase variant has improved thermostability relative to SEQ ID NO: 1 of at least 0.1°C, at least 0.5°C, at least 1.0°C, at least 1.5°C, at least 2.0°C, at least 2.5°C, at least 3.0°C, at least 3.5°C or at least 4.0°C.

[0079] In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus Bacillus or Paenibacillus, or even more preferably from the taxonomic species Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis or Paenibacillus pabuli. The parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and / or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids.

[0080] In one embodiment, the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In one embodiment, the substitution is selected from the group consisting of A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, Wand Y, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position.

[0081] In one embodiment, the number of substitutions is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions.

[0082] In a further embodiment, the invention relates to xylanase variants produced by the methods disclosed in the first aspct.

[0083] The variants can be prepared using any mutagenesis procedure known in the art, such as site-directed mutagenesis, synthetic gene construction, semi-synthetic gene construction, random mutagenesis, shuffling, etc.

[0084] Site-directed mutagenesis is a technique in which one or more (e.g., several) mutations are introduced at one or more defined sites in a polynucleotide encoding the parent.

[0085] Site-directed mutagenesis can be accomplished in vitro by PCR involving the use of oligonucleotide primers containing the desired mutation. Site-directed mutagenesis can also be performed in vitro by cassette mutagenesis involving the cleavage by a restriction enzyme at a site in the plasmid comprising a polynucleotide encoding the parent and subsequent ligation of an oligonucleotide containing the mutation in the polynucleotide. Usually the restriction enzyme that digests the plasmid and the oligonucleotide is the same, permitting sticky ends of the plasmid and the insert to ligate to one another. See, e.g., Scherer and Davis, 1979, Proc. Natl. Acad. Sci. USA 76: 4949-4955; and Barton et al., 1990, Nucleic Acids Res. 18: 7349-4966.

[0086] Site-directed mutagenesis can also be accomplished in vivo by methods known in the art. See, e.g., U.S. Patent Application Publication No. 2004 / 0171154; Storici et al., 2001, Nature Biotechnol. 19: 773-776; Kren et al., 1998, Nat. Med. 4: 285-290; and Calissano and Macino, 1996, Fungal Genet. Newslett. 43: 15-16.

[0087] Any site-directed mutagenesis procedure can be used in the present invention. There are many commercial kits available that can be used to prepare variants.

[0088] Synthetic gene construction entails in vitro synthesis of a designed polynucleotide molecule to encode a polypeptide of interest. Gene synthesis can be performed utilizing a number of techniques, such as the multiplex microchip-based technology described by Tian et al. (2004, Nature 432: 1050-1054) and similar technologies wherein oligonucleotides are synthesized and assembled upon photo-programmable microfluidic chips.

[0089] Single or multiple amino acid substitutions, deletions, and / or insertions can be made and tested using known methods of mutagenesis, recombination, and / or shuffling, followed by a relevant screening procedure, such as those disclosed by Reidhaar-Olson and Sauer, 1988, Science 241: 53-57; Bowie and Sauer, 1989, Proc. Natl. Acad. Sci. USA 86: 2152-2156; WO 95 / 17413; or WO 95 / 22625. Other methods that can be used include error-prone PCR, phage display (e.g., Lowman et al., 1991, Biochemistry 30: 10832-10837; U.S. Patent No. 5,223,409; WO 92 / 06204) and region-directed mutagenesis (Derbyshire et al., 1986, Gene 46: 145; Ner et al., 1988, DNA 7: 127).

[0090] Mutagenesis / shuffling methods can be combined with high-throughput, automated screening methods to detect activity of cloned, mutagenized polypeptides expressed by host cells (Ness et al., 1999, Nature Biotechnology 17: 893-896). Mutagenized DNA molecules that encode active polypeptides can be recovered from the host cells and rapidly sequenced using standard methods in the art. These methods allow the rapid determination of the importance of individual amino acid residues in a polypeptide.

[0091] Semi-synthetic gene construction is accomplished by combining aspects of synthetic gene construction, and / or site-directed mutagenesis, and / or random mutagenesis, and / or shuffling. Semi-synthetic construction is typified by a process utilizing polynucleotide fragments that are synthesized, in combination with PCR techniques. Defined regions of genes may thus be synthesized de novo, while other regions may be amplified using site-specific mutagenic primers, while yet other regions may be subjected to error-prone PCR or non-error prone PCR amplification. Polynucleotide subsequences may then be shuffled.Xylanase variants

[0092] The present invention relates to xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and wherein the position corresponds to the position of SEQ ID NO: 1, wherein the variant has improved thermostability compared to the SEQ ID NO: 1.

[0093] The variant has a sequence identity of at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%, but less than 100%, to SEQ ID NO: 1.

[0094] The xylanase variant has improved thermostability relative to the parent xylanase. In one embodiment, the xylanase variant has improved thermostability relative to SEQ ID NO: 1of at least 0.1°C, at least 0.5°C, at least 1.0°C, at least 1.5°C, at least 2.0°C, at least 2.5°C, at least 3.0°C, at least 3.5°C or at least 4.0°C.

[0095] In one embodiment, the number of alterations is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 substitutions.

[0096] In one embodiment of the second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises an alteration at one or more positions corresponding to positions 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 31, 32, 33, 34, 39, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 64, 65, 67, 68, 79, 82, 88, 90, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 127, 128, 129, 131, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 205, 209, 212, 217, 218, 221, 224, 231, 235, 237, 238, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 338, 339, 340, 342, 343, 344, 345, 346, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1, and wherein the variant has improved thermostability compared to SEQ ID NO: 1 . In one embodiment, the thermostability is improved by at least 0.1°C, such as at least 0.5°C, at least 1.0°C, at least 1.5°C, at least 2.0°C, at least 2.5°C, at least 3.0°C, at least 3.5°C or at least 4.0°C.

[0097] In one embodiment, the number of alterations in the variants of the present invention is 1-50, e.g., 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 alterations.

[0098] In an embodiment, the one or more further positions are selected from the group consisting of positions 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 31, 32, 33, 34, 43, 44, 45, 46, 48, 50, 58, 59, 61, 62, 65, 67, 68, 79, 82, 88, 94, 101, 102, 104, 110, 112, 113, 116, 119, 120, 123, 126, 128, 129, 135, 143, 145, 146, 159, 160, 165, 168, 176, 179, 181, 188, 191, 194, 195, 196, 197, 209, 212, 217, 218, 221, 224, 231, 235, 237, 242, 269, 280, 282, 295, 298, 299, 300, 302, 305, 306, 307, 311, 312, 313, 322, 323, 324, 333, 334, 335, 336, 337, 339, 340, 342, 343, 344, 345, 347, 349, 350, 354, 357, 359, 360, 363, 364, 366, 367, 368, 371, 373, 374, 376, 377, 378, 380, 385, 388, 390 and 391 of SEQ ID NO: 1 and the thermostability is improved by at least 0.5°C.

[0099] In an embodiment, the one or more further positions are selected from the group consisting of positions 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 18, 31, 34, 43, 45, 46, 48, 50, 58, 59, 61, 62, 67, 79, 88, 94, 101, 102, 104, 112, 113, 120, 128, 143, 145, 146, 159, 165, 176, 179, 181, 188, 194, 195, 196, 197, 209, 212, 221, 224, 231, 235, 237, 269, 282, 295, 298, 299, 302, 307, 311, 312, 313, 322, 323, 333, 334, 335, 336, 337, 339, 340, 342, 343, 344, 345, 347, 357, 359, 363, 366, 367, 368, 371, 373, 374, 376, 378, 380, 388 and 391 of SEQ ID NO: 1 and the thermostability is improved by at least 1.0°C.

[0100] In an embodiment, the one or more further positions are selected from the group consisting of positions 4, 9, 11, 12, 14, 18, 31, 45, 48, 50, 59, 61, 79, 88, 94, 101, 102, 104, 143, 145, 146, 159, 165, 176, 179, 181, 196, 197, 209, 212, 224, 231, 235, 269, 282, 295, 298, 299, 302, 307, 312, 322, 333, 335, 336, 340, 344, 357, 359, 366, 368, 371, 376, 378 and 380 of SEQ ID NO: 1 and the thermostability is improved by at least 1.5°C.

[0101] In an embodiment, the one or more further positions are selected from the group consisting of positions4, 14, 18, 50, 61, 79, 94, 102, 143, 145, 146, 165, 176, 179, 196, 197, 224, 231, 269, 298, 299, 302, 307, 333, 340 and 366 of SEQ ID NO: 1 and the thermostability is improved by at least 2.0°C.

[0102] In an embodiment, the one or more further positions are selected from the group consisting of positions 4, 14, 18, 50, 94, 102, 143, 145, 146, 165, 176, 179, 196, 197, 231, 269, 299, 302 and 333 of SEQ ID NO: 1 and the thermostability is improved by at least 2.5°C. at least 99%compared to SEQ ID NO: 1 In one embodiment of the second aspect, the present invention relates to xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and wherein the position corresponds to the position of SEQ ID NO: 1, wherein the variant has improved thermostability compared to the SEQ ID NO: 1 and comprises one or more further substitutions selected from the group consisting of S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6K, T6Q, T6L, T6N, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10A, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15L, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C, A33N, A34F, A34N, A34C, A34L, A34P, A34S, A34Q, A39S, G43W, G43A, G43N, Q44D, Q44N, Q44R, Q44Y, Q44K, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, E58R, N59C, N59V, N59D, N59K, N59L, N59S, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, N62Q, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68A, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A112V, A113E, A113Q, A113L, A113D, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, D120G, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N181T, N188M, N188E, N188L, Q191I, Q191K, Q191V, Q191R, Q191L, Q191M, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209N, S209C, S209W, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, D280R, T282M, T282H, T282R, T282C, T282V, T282L, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, S333T, N334I, N334A, N334L, T335I, T335A, G336C, G336A, G336E, V337A, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340S, N340A, N340C, V342A, V342L, V342I, V342R, V342D, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E, L343N, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L, S347F, S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350K, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W, S359E, S360R, S360G, Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D, N367E, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373E, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374T, H374S, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391G, R391P, R391H and R391V (wherein the position corresponds to the position of SEQ ID NO: 1). at least 99%compared to SEQ ID NO: 1 In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P and further selected from the group consisting of S3W, S3F, S3H, S3L, D4L, D4C, V5H, T6K, T6Q, T6L, T6N, V7F, V7S, V7C, V7A, N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, V9H, V9R, V9M, S10A, S10H, S10L, S10I, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, E12G, E12R, E12K, E12T, E12V, E12W, K13Q, K13H, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, V15F, V15L, V15N, V15K, G18H, G18Y, G18W, G18F, G18C, G18S, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, T32N, T32D, A33Q, A33H, A33M, A33Y, A34F, A34N, G43W, G43A, G43N, Q44D, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, Q46D, Q46H, Q46C, Q46S, Q46T, G48L, G48V, (G48I, G48Q, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, E58K, N59C, N59V, N59D, N59K, N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, K65I, K65L, V67A, V67S, V67F, E68W, E68V, E68I, I79K, I79R, A82G, P88M, P88F, P88T, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112G, A112T, A113E, A113Q, A113L, Q116E, Q116A, Q116G, N119G, N119S, D120R, D120A, D120S, D120Y, D120L, T123E, T123Y, T123C, T123H, K126R, N128H, G129M, G129Q, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, E146R, E146H, E146Y, E146F, E146W, E146A, M159C, R160I, S165Y, S165M, A168I, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181A, N188M, Q191I, Q191K, Q191V, A194H, A194R, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, S209N, S209C, P212A, P212K, P212Q, P212R, P212E, P212S, P212N, K217Q, Q218H, A221R, A221K, A221H, A221Q, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280N, T282M, T282H, T282R, T282C, T282V, T282L, K295W, K295T, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, G300A, G300R, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, D305W, D305F, D305I, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, D322F, D322G, N323A, N323C, K324S, K324P, S333I, S333R, S333T, N334I, N334A, T335I, T335A, G336C, V337A, V337Q, Q339I, N340S, V342A, V342L, L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, Q344I, Q344R, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, S347R, S347H, S347I, S347A, S347G, S347K, S349R, S349C, S349A, S349V, N350K, W354L, S357V, S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S360R, Q363V, Q363R, Q363A, Q363G, P364Q, P364H, T366S, T366N, T366W, T366Q, T366C, T366V, T366A, N367Y, N367P, N367L, N367A, N367F, L368D, L368H, S371F, S371W, S371V, S371E, N373D, N373I, N373E, N373W, H374E, H374F, H374D, H374T, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, A377I, H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, T385F, T385M, V388E, V388D, V388Y, V388K, N390R, R391C, R391M, R391G and R391 and the thermostability is improved by at least 0.5°C.

[0103] In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P, and further selected from the group consisting of D4L, D4C, V5H, T6K, N8Q, N8R, V9H, S10A, S10H, A11P, A11I, A11N, A11G, A11Y, A11C, A11S, E12G, E12R, E12K, K13Q, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, G18H, G18Y, G18W, G18F, L31Q, L31H, L31P, L31G, L31S, A34F, G43W, N45D, N45W, N45S, N45F, Q46D, Q46H, G48L, G48V, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, E58P, N59C, N59V, N59D, N61W, N61L, N61D, N61E, N61H, N62A, N62V, N62L, N62C, V67A, V67S, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, A112G, A113E, A113Q, D120R, D120A, D120S, N128H, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, L179K, L179S, N181C, N188M, A194H, A194R, N195H, M196L, D197A, D197S, D197Q, D197G, D197P, S209N, S209C, P212A, P212K, P212Q, P212R, P212E, A221R, A221K, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, T237P, Y269Q, Y269M, Y269I, Y269F, Y269L, T282M, T282H, T282R, T282C, T282V, K295W, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, V302I, V302S, V302R, V302T, V302A, V302Q, V302G, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, N311R, N311M, N3111, A312I, A312R, A312M, N313D, D322F, D322G, N323A, S333I, S333R, N334I, N334A, T335I, G336C, V337A, Q339I, N340S, V342A, L343C, L343Q, Q344I, N345C, S347R, S347H, S357V, S359H, S359Q, S359F, Q363V, T366S, T366N, T366W, N367Y, L368D, S371F, S371W, S371V, N373D, N373I, N373E, H374E, H374F, W376A, W376Q, W376D, W376M, H378A, H378T, H378I, H378R, H378C, H378M, P380M, P380D, P380E, P380C, P380V, P380I, P380L, V388E, V388D and R391C and the thermostability is improved by at least 1.0°C.

[0104] In an embodiment, the one or more substitutions are selected from the group consisting of A2D and A2Q, and further selected from the group consisting of D4L, D4C, V9H, A11P, E12G, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, G18H, G18Y, L31Q, L31H, N45D, G48L, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, S50T, N59C, N61W, N61L, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, N181C, M196L, D197A, D197S, D197Q, D197G, S209N, S209C, P212A, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, Y269Q, Y269M, T282M, K295W, R298Q, R298A, R298E, R298M, R298T, P299W, P299A, P299K, P299F, P299Y, P299Q, V302I, V302S, V302R, T307I, T307N, T307R, A312I, D322F, S333I, S333R, T335I, G336C, N340S, Q344I, S357V, S359H, T366S, L368D, S371F, W376A, H378A, P380M and P380D and the thermostability is improved by at least 1.5°C.

[0105] In an embodiment, the one or more substitutions are selected from the group consisting of A2D and and further selected from the group consisting ofD4L, Q14K, Q14Y, Q14A, Q14V, Q14W, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N61W, I79K, T94H, S102R, Y143H, Y143R, H145Y, E146R, E146H, S165Y, S165M, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, D197G, D224Q, Y231T, Y231V, Y231S, Y231A, Y269Q, R298Q, P299W, P299A, P299K, P299F, V302I, V302S, T307I, S333I, N340S and T366S and the thermostability is improved by at least 2.0°C.

[0106] In an embodiment, the one or more substitutions are selected from the group consisting of A2D and further selected from the group consisting of D4L, Q14K, Q14Y, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, T94H, S102R, Y143H, H145Y, E146R, S165Y, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, Y231T, Y231V, Y269Q, P299W, P299A, P299K, V302I and S333I and the thermostability is improved by at least 2.5°C.

[0107] In one embodiment of the second aspect, the present invention relates to xylanase variants having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% sequence identity to SEQ ID NO: 1 and comprises one or more substitutions selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further selected from the group consisting of S3W, S3F, S3H, S3L, S3G, S3M, S3T, S3P, D4L, D4C, D4Y, D4Q, D4A, D4K, D4P, V5H, V5G, V5P, T6Q, T6L, T6R, T6D, T6F, T6H, V7F, V7S, V7C, V7A, V7W, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I, N8A, V9H, V9R, V9M, S10H, S10L, S10I, S10D, S10K, S10V, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R, A11Q, E12G, E12R, E12K, E12T, E12V, E12W, E12C, K13Q, K13H, K13N, K13L, K13S, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, Q14D, V15F, V15N, V15K, V15H, G18H, G18Y, G18W, G18F, G18C, G18S, G18A, F19H, F19Y, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, L31V, T32N, T32D, A33Q, A33H, A33M, A33Y, A33K, A33R, A33C, A33N, A34F, A34C, A34L, A34Q, A39S, G43W, G43A, G43N, Q44R, Q44Y, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T, N45Y, Q46D, Q46H, Q46C, Q46S, Q46T, Q46N, Q46K, G48L, G48V, G48I, G48Q, G48C, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, E58R, N59C, N59V, N59K, N59L, N59S, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N61T, N61F, N61Q, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, Y64F, Y64N, K65I, K65L, V67A, V67S, V67F, V67G, V67K, E68W, E68V, E68I, E68H, E68N, I79K, I79R, I79V, I79A, A82G, P88M, P88F, P88T, P88W, P88Q, D90R, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A112V, A113E, A113Q, A113L, A113S, Q116E, Q116A, Q116G, N119G, N119S, N119V, N119L, N119C, N119R, D120R, D120A, D120S, D120Y, D120L, D120W, D120T, T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R, T123I, K126A, K126Y, K126L, K126F, K126W, K126E, K126H, K126Q, N127P, N127W, N128H, N128K, G129M, G129Q, G129A, G129F, G129W, N131K, N131R, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, H145W, E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G, E146S, M159C, R160I, S165Y, S165M, S165I, A168I, A168R, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N181T, N188M, N188E, N188L, Q191I, Q191V, Q191R, Q191L, Q191M, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, G205C, G205Q, S209C, S209W, P212K, P212Q, P212R, P212E, P212N, K217Q, K217M, Q218H, Q218I, A221R, A221K, A221H, A221Q, A221C, A221N, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, N238G, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, D280R, T282H, T282R, T282C, T282V, T282E, T282F, K295W, K295T, K295I, K295V, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P, R298Y, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G, P299S, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, V302F, D305W, D305F, D305I, D305M, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, T307E, T307Y, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, N313L, N313C, N313G, N313F, D322F, D322G, D322L, N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y, N323P, K324S, K324P, S333I, S333R, N334I, N334L, T335I, G336C, V337Q, V337D, V337M, V337E, V337G, N338H, Q339I, Q339T, Q339A, N340A, N340C, V342L, V342I, V342R, V342D, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, L343K, L343H, L343E, L343N, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V, N345P, G346H, S347R, S347H, S347I, S347G, S347Y, S347W, S347L, S347F, S349R, S349C, S349V, S349I, S349F, S349Y, S349T, S349M, S349D, N350A, W354L, S357V, S357Q, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, S359W, S359E, S360G, Q363V, Q363R, Q363G, Q363H, Q363L, Q363N, Q363F, P364Q, P364H, P364W, P364I, P364L, T366S, T366N, T366W, T366Q, T366C, T366V, T366L, T366K, T366R, T366G, T366I, T366Q, N367Y, N367L, N367F, N367Q, N367W, L368D, L368H, S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D, S371I, N373D, N373I, N373W, N373Y, N373A, N373H, N373Q, H374E, H374F, H374D, H374I, H374L, H374W, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F, W376R, A377I, A377V, A377M, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E, H378F, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K, P380H, T385F, T385M, T385R, V388E, V388D, V388Y, V388K, V388H, V388L, V388Q, N390R, N390M, N390P, R391C, R391M, R391P, R391H and R391V, wherein the variant has improved thermostability compared to SEQ ID NO: 1 (wherein the position corresponds to the position of SEQ ID NO: 1).

[0108] In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P and further selected from the group consisting ofS3W, S3F, S3H, S3L, D4L, D4C, V5H, T6Q, T6L, V7F, V7S, V7C, V7A, N8Q, N8F, N8W, N8Y, N8S, N8M, N8L, V9H, V9R, V9M, S10H, S10L, S10I, A11P, A11I, A11N, A11G, A11Y, A11C, A11F, A11M, A11D, A11L, A11H, A11W, A11E, E12G, E12R, E12K, E12T, E12V, E12W, K13Q, K13H, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C, V15F, V15N, V15K, G18H, G18Y, G18W, G18F, G18C, G18S, L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I, T32N, T32D, A33Q, A33H, A33M, A33Y, A34F, A34N, G43W, G43A, G43N, N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, Q46D, Q46H, Q46C, Q46S, Q46T, G48L, G48V, G48I, G48Q, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, E58K, N59C, N59V, N59K, N61W, N61L, N61E, N61H, N61M, N61Y, N61I, N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W, K65I, K65L, V67A, V67S, V67F, E68W, E68V, E68I, I79K, I79R, A82G, P88M, P88F, P88T, T94H, T101L, T101R, S102R, K104R, K104H, K110E, K110M, A113E, A113Q, A113L, Q116E, Q116A, Q116G, N119G, N119S, D120R, D120A, D120S, D120Y, D120L, T123E, T123Y, T123C, T123H, N128H, G129M, G129Q, I135T, Y143H, Y143R, Y143N, H145Y, H145C, H145K, H145A, E146R, E146H, E146Y, E146F, E146W, E146A, M159C, R160I, S165Y, S165M, A168I, F176H, F176R, F176Y, F176K, F176W, L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q, L179W, N181C, N188M, Q191I, Q191V, A194H, A194K, N195H, M196L, M196I, D197A, D197S, D197Q, D197G, D197P, D197T, D197N, S209C, P212K, P212Q, P212R, P212E, P212N, K217Q, Q218H, A221R, A221K, A221H, A221Q, D224Q, Y231T, Y231V, Y231S, Y231A, Y231C, S235A, S235G, T237P, T237R, T237K, R242I, Y269Q, Y269M, Y269I, Y269F, Y269L, D280S, T282H, T282R, T282C, T282V, K295W, K295T, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, G300A, G300R, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D, D305W, D305F, D305I, A306I, A306T, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307H, N311R, N311M, N311I, N311C, N311V, A312I, A312R, A312M, A312F, N313D, N313R, N313I, D322F, D322G, N323A, N323C, K324S, K324P, S333I, S333R, N334I, T335I, G336C, V337Q, Q339I, V342L, L343C, L343Q, L343A, L343P, L343S, L343D, L343Y, Q344I, Q344S, N345C, N345A, N345H, N345W, N345Q, N345R, S347R, S347H, S347I, S347G, S349R, S349C, S349V, W354L, S357V, S359H, S359Q, S359F, S359R, S359I, S359Y, S359A, S359P, Q363V, Q363R, Q363G, P364Q, P364H, T366N, T366W, T366Q, T366C, T366V, N367Y, N367L, N367F, L368D, L368H, S371F, S371W, S371V, S371E, N373D, N373I, N373W, H374E, H374F, H374D, W376A, W376Q, W376D, W376M, W376N, W376P, W376H, A377I, H378A, H378T, H378I, H378R, H378C, H378M, H378N, H378G, H378L, H378V, H378S, H378Y, P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, T385F, T385M, V388E, V388D, V388Y, V388K, N390R, R391C, R391M and R391 and the thermostability is improved by at least 0.5°C.

[0109] In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q, A2G, A2W, A2P and further selected from the group consisting of D4L, D4C, V5H, N8Q, V9H, S10H, A11P, A11I, A11N, A11G, A11Y, A11C, E12G, E12R, E12K, K13Q, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, G18H, G18Y, G18W, G18F, L31Q, L31H, L31P, L31G, L31S, A34F, G43W, N45D, N45W, N45S, N45F, Q46D, Q46H, G48L, G48V, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N59V, N61W, N61L, N61E, N61H, N62A, N62V, N62L, N62C, V67A, V67S, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, A113E, A113Q, D120R, D120A, D120S, N128H, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, L179K, L179S, N181C, N188M, A194H, N195H, M196L, D197A, D197S, D197Q, D197G, D197P, S209C, P212K, P212Q, P212R, P212E, A221R, A221K, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, T237P, Y269Q, Y269M, Y269I, Y269F, Y269L, T282H, T282R, T282C, T282V, K295W, R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, V302S, V302R, V302T, V302A, V302Q, V302G, T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, N311R, N311M, N3111, A312I, A312R, A312M, N313D, D322F, D322G, N323A, S333I, S333R, N334I, T335I, G336C, Q339I, L343C, L343Q, Q344I, N345C, S347R, S347H, S357V, S359H, S359Q, S359F, Q363V, T366N, T366W, N367Y, L368D, S371F, S371W, S371V, N373D, N373I, H374E, H374F, W376A, W376Q, W376D, W376M, H378A, H378T, H378I, H378R, H378C, H378M, P380M, P380D, P380E, P380C, P380V, P380I, P380L, V388E, V388D and R391C and the thermostability is improved by at least 1.0°C.

[0110] In an embodiment, the one or more substitutions are selected from the group consisting of A2D, A2Q and further selected from the group consisting of D4L, D4C, V9H, A11P, E12G, Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, G18H, G18Y, L31Q, L31H, N45D, G48L, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N59C, N61W, N61L, I79K, P88M, P88F, T94H, T101L, T101R, S102R, K104R, Y143H, Y143R, H145Y, E146R, E146H, E146Y, E146F, M159C, S165Y, S165M, F176H, F176R, F176Y, F176K, L179D, L179N, L179C, L179A, L179R, N181C, M196L, D197A, D197S, D197Q, D197G, S209C, D224Q, Y231T, Y231V, Y231S, Y231A, S235A, Y269Q, Y269M, K295W, R298Q, R298A, R298E, R298M, R298T, P299W, P299A, P299K, P299F, P299Y, P299Q, V302S, V302R, T307I, T307N, T307R, A312I, D322F, S333I, S333R, T335I, G336C, Q344I, S357V, S359H, L368D, S371F, W376A, H378A, P380M and P380D and the thermostability is improved by at least 1.5°C.

[0111] In an embodiment, the one or more substitutions are selected from the group consisting of A2D and further selected from the group consisting of D4L, Q14K, Q14Y, Q14A, Q14V, Q14W, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, N61W, I79K, T94H, S102R, Y143H, Y143R, H145Y, E146R, E146H, S165Y, S165M, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, D197G, D224Q, Y231T, Y231V, Y231S, Y231A, Y269Q, R298Q, P299W, P299A, P299K, P299F, V302S, T307I and S333I and the thermostability is improved by at least 2.0°C.

[0112] In an embodiment, the one or more substitutions are selected from the group consisting of A2D and further selected from the group consisting of D4L, Q14K, Q14Y, G18H, S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E, T94H, S102R, Y143H, H145Y, E146R, S165Y, F176H, F176R, L179D, L179N, L179C, L179A, M196L, D197A, D197S, D197Q, Y231T, Y231V, Y269Q, P299W, P299A, P299K and S333I and the thermostability is improved by at least 2.5°C.

[0113] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 2 of SEQ ID NO: 1, wherein the substitution is selected compared to SEQ ID NO: 1 of A2D, A2Q, A2G, A2W or A2P.

[0114] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1, and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 3 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S3W, S3F, S3H, S3L, S3G, S3M, S3T or S3P.

[0115] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 4 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D4L, D4C, D4Y, D4Q, D4A, D4K or D4P.

[0116] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 5 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V5H, V5G or V5P.

[0117] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises or consists of a substitution at a position corresponding to position 6 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T6K, T6Q, T6L, T6N, T6R, T6D, T6F or T6H.

[0118] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises or consists of a substitution at a position corresponding to position 7 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V7F, V7S, V7C, V7A or V7W.

[0119] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 8 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N8Q, N8R, N8D, N8F, N8W, N8Y, N8S, N8M, N8L, N8V, N8T, N8I or N8A.

[0120] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 9 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V9H, V9R or V9M.

[0121] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 10 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises or the substitution S10A, S10H, S10L, S10I, S10D, S10K or S10V.

[0122] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 11 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution A11P, A11I, A11N, A11G, A11Y, A11C, A11S, A11F, A11M, A11D, A11L, A11H, A11W, A11E, A11V, A11R or A11Q.

[0123] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 12 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution E12G, E12R, E12K, E12T, E12V, E12W or E12C.

[0124] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 13 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution K13Q, K13H, K13N, K13L or K13S.

[0125] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 14 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution Q14K, Q14Y, Q14A, Q14V, Q14W, Q14F, Q14S, Q14P, Q14G, Q14R, Q14M, Q14H, Q14C or Q14D.

[0126] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 15 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution V15F, V15L, V15N, V15K or V15H.

[0127] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 18 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution G18H, G18Y, G18W, G18F, G18C, G18S or G18A.

[0128] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 19 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution F19H or F19Y.

[0129] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 31 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution L31Q, L31H, L31P, L31G, L31S, L31R, L31N, L31I or L31V.

[0130] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 32 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution T32N or T32D.

[0131] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 33 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution A33Q, A33H, A33M, A33Y, A33K, A33E, A33R, A33C or A33N.

[0132] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises or a substitution at a position corresponding to position 34 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution A34F, A34N, A34C, A34L, A34P, A34S or A34Q.

[0133] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 39 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution A39S.

[0134] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 43 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution G43W, G43A or G43N.

[0135] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 44 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Q44D, Q44N, Q44R, Q44Y or Q44K.

[0136] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 45 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution N45D, N45W, N45S, N45F, N45I, N45E, N45H, N45Q, N45G, N45P, N45T or N45Y.

[0137] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 46 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution Q46D, Q46H, Q46C, Q46S, Q46T, Q46N or Q46K.

[0138] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 48 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution G48L, G48V, G48I, G48Q or G48C.

[0139] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 50 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises the substitution S50H, S50F, S50R, S50K, S50I, S50L, S50Q, S50Y, S50N, S50V, S50M, S50P, S50A, S50C, S50G, S50D, S50E or S50T.

[0140] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises a substitution at a position corresponding to position 58 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises or consists of the substitution E58P, E58K or E58R.

[0141] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 59 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N59C, N59V, N59D, N59K, N59L or N59S.

[0142] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99%sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 61 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N61W, N61L, N61D, N61E, N61H, N61M, N61Y, N61I, N61T, N61F or N61Q.

[0143] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 62 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N62A, N62V, N62L, N62C, N62T, N62Y, N62F, N62M, N62W or N62Q.

[0144] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 64 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Y64F or Y64N.

[0145] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 65 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution K65I or K65L.

[0146] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 67 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V67A, V67S, V67F, V67G or V67K.

[0147] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitutionat a position corresponding to position 68 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitutionE68W, E68V, E68I, E68A, E68H or E68N.

[0148] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 79 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitutionl79K, I79R, I79V or I79A.

[0149] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 82 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A82G.

[0150] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitutionat a position corresponding to position 88 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution P88M, P88F, P88T, P88W or P88Q.

[0151] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 90 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D90R.

[0152] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 94 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T94H.

[0153] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitution at a position corresponding to position 101 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T101L or T101R.

[0154] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a substitutionat a position corresponding to position 102 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S102R.

[0155] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 104 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution 104R or K104H.

[0156] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 110 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution K110E or K110M.

[0157] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 112 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A112G, A112T or A112V.

[0158] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 113 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A113E, A113Q, A113L, A113D or A113S.

[0159] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 116 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Q116E, Q116A or Q116G.

[0160] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 119 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N119G, N119S, N119V, N119L, N119C or N119R.

[0161] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 120 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D120R, D120A, D120S, D120Y, D120L, D120W, D120T or D120G.

[0162] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 123 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T123E, T123Y, T123C, T123H, T123Q, T123K, T123V, T123G, T123R or T123I.

[0163] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 126 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution K126R, K126A, K126Y, K126L, K126F, K126W, K126E, K126H or K126Q.

[0164] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 127 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N127P or N127W.

[0165] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 128 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N128H or N128K.

[0166] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 129 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution G129M, G129Q, G129A, G129F or G129W.

[0167] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 131 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N131K or N131R.

[0168] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 135 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution I135T.

[0169] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 143 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Y143H, Y143R or Y143N.

[0170] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 145 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution H145Y, H145C, H145K, H145A or H145W.

[0171] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 146 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution E146R, E146H, E146Y, E146F, E146W, E146A, E146K, E146G or E146S.

[0172] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 159 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution M159C.

[0173] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 160 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution R160I.

[0174] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 165 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S165Y, S165M or S165I.

[0175] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 168 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A168I or A168R.

[0176] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 176 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution F176H, F176R, F176Y, F176K or F176W.

[0177] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 179 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution L179D, L179N, L179C, L179A, L179R, L179K, L179S, L179Q or L179W.

[0178] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 181 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N181C, N181A or N181T.

[0179] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 188 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N188M, N188E or N188L.

[0180] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 191 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Q191I, Q191K, Q191V, Q191R, Q191L or Q191M.

[0181] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 194 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A194H, A194R or A194K.

[0182] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 195 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N195H.

[0183] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 196 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution M196L or M196I.

[0184] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 197 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D197A, D197S, D197Q, D197G, D197P, D197T or D197N.

[0185] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 205 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution G205C or G205Q.

[0186] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 209 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S209N, S209C or S209W.

[0187] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 212 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution P212A, P212K, P212Q, P212R, P212E, P212S or P212N.

[0188] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 217 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution K217Q or K217M.

[0189] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 218 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Q218H or Q218I.

[0190] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 221 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A221R, A221K, A221H, A221Q, A221C or A221N.

[0191] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 224 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D224Q.

[0192] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 231 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Y231T, Y231V, Y231S, Y231A or Y231C.

[0193] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 235 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S235A or S235G.

[0194] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 237 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T237P, T237R or T237K.

[0195] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 238 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N238G.

[0196] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 242 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution R242I.

[0197] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 269 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Y269Q, Y269M, Y269I, Y269F or Y269L.

[0198] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 280 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D280S, D280N or D280R.

[0199] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 282 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T282M, T282H, T282R, T282C, T282V, T282L, T282E or T282F.

[0200] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 295 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution K295W, K295T, K295I or K295V.

[0201] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 298 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution R298Q, R298A, R298E, R298M, R298T, R298N, R298C, R298I, R298D, R298L, R298G, R298W, R298S, R298P or R298Y.

[0202] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 299 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution P299W, P299A, P299K, P299F, P299Y, P299Q, P299N, P299H, P299E, P299D, P299R, P299M, P299C, P299G or P299S.

[0203] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 300 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution G300A or G300R.

[0204] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 302 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V302I, V302S, V302R, V302T, V302A, V302Q, V302G, V302C, V302K, V302W, V302P, V302D or V302F.

[0205] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 305 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D305W, D305F, D305I or D305M.

[0206] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 306 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A306I or A306T.

[0207] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 307 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T307I, T307N, T307R, T307Q, T307K, T307F, T307M, T307D, T307V, T307W, T307C, T307S, T307H, T307E or T307Y.

[0208] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 311 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N311R, N311M, N311I, N311C or N311V.

[0209] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 312 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A312I, A312R, A312M or A312F.

[0210] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 313 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N313D, N313R, N313I, N313L, N313C, N313G or N313F.

[0211] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 322 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution D322F, D322G or D322L.

[0212] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 323 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N323A, N323C, N323Q, N323L, N323G, N323R, N323E, N323S, N323Y or N323P.

[0213] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 324 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution K324S or K324P.

[0214] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 333 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S333I, S333R or S333T.

[0215] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 334 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N334I, N334A or N334L.

[0216] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 335 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T335I or T335A.

[0217] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 336 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution G336C, G336A or G336E.

[0218] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 337 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V337A, V337Q, V337D, V337M, V337E or V337G.

[0219] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 338 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N338H.

[0220] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 339 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Q339I, Q339T or Q339A.

[0221] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 340 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N340S, N340A or N340C.

[0222] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 342 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V342A, V342L, V342I, V342R or V342D.

[0223] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 343 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution L343C, L343Q, L343I, L343A, L343P, L343S, L343D, L343Y, L343F, L343K, L343H, L343E or L343N.

[0224] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 344 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Q344I, Q344R or Q344S.

[0225] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 345 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N345C, N345A, N345H, N345W, N345Q, N345R, N345I, N345V or N345P.

[0226] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 346 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution G346H.

[0227] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 347 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S347R, S347H, S347I, S347A, S347G, S347K, S347Y, S347W, S347T, S347L or S347F.

[0228] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 349 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S349R, S349C, S349A, S349V, S349I, S349F, S349Y, S349T, S349M or S349D.

[0229] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 350 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N350K or N350A.

[0230] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 354 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution W354L.

[0231] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 357 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S357V or S357Q.

[0232] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 359 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S359H, S359Q, S359F, S359R, S359I, S359G, S359Y, S359A, S359P, S359N, S359W or S359E.

[0233] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 360 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S360R or S360G.

[0234] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 363 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution Q363V, Q363R, Q363A, Q363G, Q363H, Q363L, Q363N or Q363F.

[0235] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 364 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution P364Q, P364H, P364W, P364I or P364L.

[0236] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 366 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T366S, T366N, T366W, T366Q, T366C, T366V, T366A, T366S, T366L, T366K, T366R, T366G, T366I or T366Q.

[0237] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 367 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N367Y, N367P, N367L, N367A, N367F, N367Q, N367W, N367D or N367E.

[0238] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 368 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution L368D or L368H.

[0239] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 371 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution S371F, S371W, S371V, S371E, S371R, S371H, S371Q, S371D or S371I.

[0240] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 373 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N373D, N373I, N373E, N373W, N373Y, N373A, N373H or N373Q.

[0241] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 374 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution H374E, H374F, H374D, H374T, H374S, H374I, H374L or H374W.

[0242] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 376 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution W376A, W376Q, W376D, W376M, W376N, W376P, W376H, W376Y, W376L, W376E, W376G, W376F or W376R.

[0243] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 377 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution A377I, A377V or A377M.

[0244] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 378 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution H378A, H378T, H378I, H378R, H378C, H378M, H378Q, H378N, H378G, H378L, H378V, H378S, H378Y, H378K, H378D, H378P, H378E or H378F.

[0245] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 380 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution P380M, P380D, P380E, P380C, P380V, P380I, P380L, P380F, P380G, P380K or P380H.

[0246] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 385 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution T385F, T385M or T385R.

[0247] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 388 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution V388E, V388D, V388Y, V388K, V388H, V388L or V388Q.

[0248] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 390 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution N390R, N390M or N390P.

[0249] In one embodiment of the second aspect, the invention relates to a xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and further comprises of a subtitution at a position corresponding to position 391 of SEQ ID NO: 1. In an embodiment, the substitution is selected from Ala, Arg, Asn, Asp, Cys, Gln, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, with the proviso that the substituted amino acid residue is different from the naturally-occurring amino acid residue in that position. In an embodiment, the xylanase variant has improved thermostability compared to SEQ ID NO: 1 and comprises of the substitution R391C, R391M, R391G, R391P, R391H or R391V.

[0250] The xylanase variants of the present invention may further comprise one or more additional alterations than those described above at one or more (e.g., several) other positions.

[0251] The amino acid changes may be of a minor nature, that is conservative amino acid substitutions or insertions that do not significantly affect the folding and / or activity of the protein; small deletions, typically of 1-30 amino acids; small amino- or carboxyl-terminal extensions, such as an amino-terminal methionine residue; a small linker peptide of up to 20-25 residues; or a small extension that facilitates purification by changing net charge or another function, such as a poly-histidine tract, an antigenic epitope or a binding domain.

[0252] Examples of conservative substitutions are within the groups of basic amino acids (arginine, lysine and histidine), acidic amino acids (glutamic acid and aspartic acid), polar amino acids (glutamine and asparagine), hydrophobic amino acids (leucine, isoleucine and valine), aromatic amino acids (phenylalanine, tryptophan and tyrosine), and small amino acids (glycine, alanine, serine, threonine and methionine). Amino acid substitutions that do not generally alter specific activity are known in the art and are described, for example, by H. Neurath and R.L. Hill, 1979, In, The Proteins, Academic Press, New York. Common substitutions are Ala / Ser, Val / Ile, Asp / Glu, Thr / Ser, Ala / Gly, Ala / Thr, Ser / Asn, Ala / Val, Ser / Gly, Tyr / Phe, Ala / Pro, Lys / Arg, Asp / Asn, Leu / lle, Leu / Val, Asn / Gln, Gln / Glu, Ala / Glu, and Asp / Gly. Other examples of conservative substitutions are G to A; A to G, S; V to I, L, A, T, S; I to V, L, M; L to I, M, V; M to L, I, V; P to A, S, N; F to Y, W, H; Y to F, W, H; W to Y, F, H; R to K, E, D; K to R, E, D; H to Q, N, S; D to N, E, K, R, Q; E to Q, D, K, R, N; S to T, A; T to S, V, A; C to S, T, A; N to D, Q, H, S; Q to E, N, H, K, R.

[0253] Alternatively, the amino acid changes are of such a nature that the physico-chemical properties of the polypeptides are altered. For example, amino acid changes may improve the thermal stability of the polypeptide, alter the substrate specificity, change the pH optimum, and the like.

[0254] Essential amino acids in a polypeptide can be identified according to procedures known in the art, such as site-directed mutagenesis or alanine-scanning mutagenesis (Cunningham and Wells, 1989, Science 244: 1081-1085). In the latter technique, single alanine mutations are introduced at every residue in the molecule, and the resultant mutant molecules are tested for xylanase activity to identify amino acid residues that are critical to the activity of the molecule. See also, Hilton et al., 1996, J. Biol. Chem. 271: 4699-4708. The active site of the enzyme or other biological interaction can also be determined by physical analysis of structure, as determined by such techniques as nuclear magnetic resonance, crystallography, electron diffraction, or photoaffinity labeling, in conjunction with mutation of putative contact site amino acids. See, for example, de Vos et al., 1992, Science 255: 306-312; Smith et al., 1992, J. Mol. Biol. 224: 899-904; Wlodaver et al., 1992, FEBS Lett. 309: 59-64. The identity of essential amino acids can also be inferred from an alignment with a related polypeptide.

[0255] In one embodiment, the variant comprises a substitution at 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 positions.

[0256] In one embodiment of any part of the second aspect, the thermostability may be determined as described in Example 2 herein.Granules Comprising Xylanase Variants

[0257] In a third aspect, the present invention relates to granules comprising the xylanase variants as disclosed in any part of the second aspect of the invention.

[0258] Thus in one embodiment of the third aspect, the invention relates to granules comprising xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and wherein the position corresponds to the position of SEQ ID NO: 1, wherein the variant has improved thermostability compared to the SEQ ID NO: 1.Liquid formulations comprising polypeptides Having Alpha-galactosidase Activity

[0259] In a fourth aspect, the present invention relates to liquid formulations comprising the xylanase variants as disclosed in any part of the second aspect of the invention. Accordingly, an aspect of the invention is directed to a liquid formulation comprising the xylanase variant defined by the invention, wherein the xylanase variant is dosed between 0.01% to 25% w / w of liquid formulation, preferably 0.05% to 20% w / w, more preferably 0.2% to 15% w / w, more preferably 0.5% to 15% w / w or most preferably 1.0% to 10% w / w xylanase variant.

[0260] Thus, in one embodiment of the fourth aspect, the invention relates to liquid formulations comprising: (A) 0.001% to 25% w / w of xylanase variants having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and wherein the position corresponds to the position of SEQ ID NO: 1, wherein the variant has improved thermostability compared to the SEQ ID NO: 1; and (B) water.

[0261] In one embodiment, the liquid formulation comprises 20% to 80% w / w of polyol.

[0262] In one embodiment, the liquid formulation comprises 0.001% to 2.0% w / w preservative.

[0263] In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more polyols, preferably a polyol selected from the group consisting of glycerol, sorbitol, propylene glycol (MPG), ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, dipropylene glycol, polyethylene glycol (PEG) having an average molecular weight below about 600 and polypropylene glycol (PPG) having an average molecular weight below about 600, more preferably selected from the group consisting of glycerol, sorbitol and propylene glycol (MPG) or any combination thereof.

[0264] In one embodiment to any part of the fourth aspect, the liquid formulation comprises 20%-80% polyol (i.e. total amount of polyol), preferably 25%-75% polyol, more preferably 30%-70% polyol, more preferably 35%-65% polyol or most preferably 40%-60% polyol. In one embodiment to any part of the fourth aspect, the liquid formulation comprises 20%-80% polyol, preferably 25%-75% polyol, more preferably 30%-70% polyol, more preferably 35%-65% polyol or most preferably 40%-60% polyol wherein the polyol is selected from the group consisting of glycerol, sorbitol, propylene glycol (MPG), ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, dipropylene glycol, polyethylene glycol (PEG) having an average molecular weight below about 600 and polypropylene glycol (PPG) having an average molecular weight below about 600. In one embodiment to any part of the fourth aspect, the liquid formulation comprises 20%-80% polyol (i.e. total amount of polyol), preferably 25%-75% polyol, more preferably 30%-70% polyol, more preferably 35%-65% polyol or most preferably 40%-60% polyol wherein the polyol is selected from the group consisting of glycerol, sorbitol and propylene glycol (MPG).

[0265] In one embodiment to any part of the fourth aspect, the preservative is selected from the group consisting of sodium sorbate, potassium sorbate, sodium benzoate and potassion benzoate or any combination thereof. In one embodiment, the liquid formulation comprises 0.02% to 1.5% w / w preservative, more preferably 0.05% to 1.0% w / w preservative or most preferably 0.1% to 0.5% w / w preservative. In one embodiment, the liquid formulation comprises 0.001% to 2.0% w / w preservative (i.e. total amount of preservative), preferably 0.02% to 1.5% w / w preservative, more preferably 0.05% to 1.0% w / w preservative or most preferably 0.1% to 0.5% w / w preservative wherein the preservative is selected from the group consisting of sodium sorbate, potassium sorbate, sodium benzoate and potassion benzoate or any combination thereof.

[0266] In one embodiment to any part of the fourth aspect, the liquid formulation comprises 0.01% to 25% w / w xylanase variant, preferably 0.05% to 20% w / w, more preferably 0.2% to 15% w / w, more preferably 0.5% to 15% w / w or most preferably 1.0% to 10% w / w xylanase variant.

[0267] In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more formulating agents (such as those described herein), preferably a formulating agent selected from the list consisting of glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch, PVA, acetate and phosphate, preferably selected from the list consisting of 1, 2-propylene glycol, 1, 3-propylene glycol, sodium sulfate, dextrin, cellulose, sodium thiosulfate, kaolin and calcium carbonate.

[0268] In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more additional enzymes. The one or more additional enzymes is preferably selected from the group consisting of acetylxylan esterase, acylglycerol lipase, amylase, alpha-amylase, beta-amylase, arabinofuranosidase, cellobiohydrolases, cellulase, feruloyl esterase, galactanase, alpha-galactosidase, beta-galactosidase, beta-glucanase, beta-glucosidase, lysophospholipase, lysozyme, alpha-mannosidase, beta-mannosidase (mannanase), phytase, phospholipase A1, phospholipase A2, phospholipase D, protease, pullulanase, pectinesterase, triacylglycerol lipase, xylanase, beta-xylosidase or any combination thereof.

[0269] In one embodiment to any part of the fourth aspect, the liquid formulation comprises one or more probiotics. The one or more probiotics is preferably selected from the group consisting of Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus cereus, Bacillus pumilus, Bacillus polymyxa, Bacillus megaterium, Bacillus coagulans, Bacillus circulans, Bifidobacterium bifidum, Bifidobacterium animalis, Bifidobacterium sp., Carnobacterium sp., Clostridium butyricum, Clostridium sp., Enterococcus faecium, Enterococcus sp., Lactobacillus sp., Lactobacillus acidophilus, Lactobacillus farciminus, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus salivarius, Lactococcus lactis, Lactococcus sp., Leuconostoc sp., Megasphaera elsdenii, Megasphaera sp., Pediococsus acidilactici, Pediococcus sp., Propionibacterium thoenii, Propionibacterium sp. and Streptococcus sp. or any combination thereof.Parent Xylanases

[0270] In one embodiment, the parent xylanase is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus Bacillus or Paenibacillus, or even more preferably from the taxonomic species Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis or Paenibacillus pabuli. The parent xylanase has at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to SEQ ID NO: 1 and is obtained or obtainable from the taxonomic order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus Bacillus or Paenibacillus, or even more preferably from the taxonomic species Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis or Paenibacillus pabuli. In one embodiment, the xylanase is a GH30 subfamily 8 xylanase (herein referred to as GH30_8 xylanases).

[0271] The parent xylanase may be (a) a polypeptide having at least 90% sequence identity to SEQ ID NO: 1, e.g., at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%, which have xylanase activity. In one aspect, the amino acid sequence of the parent differs by up to 10 amino acids, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, from SEQ ID NO: 1. In one embodiment, the parent xylanase comprises or consists of the amino acid sequence of SEQ ID NO: 1, is a fragment of SEQ ID NO: 1 wherein the fragment has xylanase activity or comprises the amino acid sequence of SEQ ID NO: 1 and an N- and / or C-terminal extension of up to 10 amino acids, e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids.

[0272] The parent may be obtained from microorganisms of any genus. For purposes of the present invention, the term "obtained from" as used herein in connection with a given source shall mean that the parent encoded by a polynucleotide is produced by the source or by a strain in which the polynucleotide from the source has been inserted. In one aspect, the parent is secreted extracellularly.

[0273] The polypeptide may be a bacterial polypeptide. For example, the polypeptide may be a Gram-positive bacterial polypeptide such as a Bacillus, Clostridium, Enterococcus, Geobacillus, Lactobacillus, Lactococcus, Oceanobacillus, Staphylococcus, Streptococcus, or Streptomyces polypeptide having xylanase activity. In one embodiment, the polypeptide is from a bacterium of the class Bacilli, such as from the order Bacillales, or preferably the taxonomic family Bacillaceae or Paenibacillaceae, or more preferably from the taxonomic genus Bacillus or Paenibacillus, or even more preferably from the taxonomic species Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis or Paenibacillus pabuli.

[0274] In one aspect, the parent is a Bacillus alkalophilus, Bacillus amyloliquefaciens, Bacillus brevis, Bacillus circulans, Bacillus clausii, Bacillus coagulans, Bacillus firmus, Bacillus lautus, Bacillus lentus, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus stearothermophilus, Bacillus subtilis, or Bacillus thuringiensis xylanase.

[0275] In a preferred aspect, the parent is a Bacillus subtilis xylanase, e.g., the xylanase having the amino acid sequence of SEQ ID NO: 1.

[0276] It will be understood that for the aforementioned species, the invention encompasses both the perfect and imperfect states, and other taxonomic equivalents, e.g., anamorphs, regardless of the species name by which they are known. Those skilled in the art will readily recognize the identity of appropriate equivalents.

[0277] Strains of these species are readily accessible to the public in a number of culture collections, such as the American Type Culture Collection (ATCC), Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ), Centraalbureau Voor Schimmelcultures (CBS), and Agricultural Research Service Patent Culture Collection, Northern Regional Research Center (NRRL).

[0278] The parent may be identified and obtained from other sources including microorganisms isolated from nature (e.g., soil, composts, water, etc.) or DNA samples obtained directly from natural materials (e.g., soil, composts, water, etc.) using the above-mentioned probes. Techniques for isolating microorganisms and DNA directly from natural habitats are well known in the art. A polynucleotide encoding a parent may then be obtained by similarly screening a genomic DNA or cDNA library of another microorganism or mixed DNA sample. Once a polynucleotide encoding a parent has been detected with the probe(s), the polynucleotide can be isolated or cloned by utilizing techniques that are known to those of ordinary skill in the art (see, e.g., Sambrook et al., 1989, supra).Polynucleotides

[0279] The present invention also relates to isolated polynucleotides encoding a variant of the present invention.Nucleic Acid Constructs

[0280] The present invention also relates to nucleic acid constructs comprising a polynucleotide encoding a variant of the present invention operably linked to one or more control sequences that direct the expression of the coding sequence in a suitable host cell under conditions compatible with the control sequences.

[0281] The polynucleotide may be manipulated in a variety of ways to provide for expression of a variant. Manipulation of the polynucleotide prior to its insertion into a vector may be desirable or necessary depending on the expression vector. The techniques for modifying polynucleotides utilizing recombinant DNA methods are well known in the art.

[0282] The control sequence may be a promoter, a polynucleotide which is recognized by a host cell for expression of the polynucleotide. The promoter contains transcriptional control sequences that mediate the expression of the variant. The promoter may be any polynucleotide that shows transcriptional activity in the host cell including mutant, truncated, and hybrid promoters, and may be obtained from genes encoding extracellular or intracellular polypeptides either homologous or heterologous to the host cell.

[0283] Examples of suitable promoters for directing transcription of the nucleic acid constructs of the present invention in a bacterial host cell are the promoters obtained from the Bacillus amyloliquefaciens alpha-amylase gene (amyQ), Bacillus licheniformis alpha-amylase gene (amyL), Bacillus licheniformis penicillinase gene (penP), Bacillus stearothermophilus maltogenic amylase gene (amyM), Bacillus subtilis levansucrase gene (sacB), Bacillus subtilis xylA and xylB genes, Bacillus thuringiensis cryIIIA gene (Agaisse and Lereclus, 1994, Molecular Microbiology 13: 97-107), E. coli lac operon, E. coli trc promoter (Egon et al., 1988, Gene 69: 301-315), Streptomyces coelicolor agarase gene (dagA), and prokaryotic beta-lactamase gene (Villa-Kamaroff et al., 1978, Proc. Natl. Acad. Sci. USA 75: 3727-3731), as well as the tac promoter (DeBoer et al., 1983, Proc. Natl. Acad. Sci. USA 80: 21-25). Further promoters are described in "Useful proteins from recombinant bacteria" in Gilbert et al., 1980, Scientific American 242: 74-94; and in Sambrook et al., 1989, supra. Examples of tandem promoters are disclosed in WO 99 / 43835.

[0284] Examples of suitable promoters for directing transcription of the nucleic acid constructs of the present invention in a filamentous fungal host cell are promoters obtained from the genes for Aspergillus nidulans acetamidase, Aspergillus niger neutral alpha-amylase, Aspergillus niger acid stable alpha-amylase, Aspergillus niger or Aspergillus awamori glucoamylase (glaA), Aspergillus oryzae TAKA amylase, Aspergillus oryzae alkaline protease, Aspergillus oryzae triose phosphate isomerase, Fusarium oxysporum trypsin-like protease (WO 96 / 00787), Fusarium venenatum amyloglucosidase (WO 00 / 56900), Fusarium venenatum Daria (WO 00 / 56900), Fusarium venenatum Quinn (WO 00 / 56900), Rhizomucor miehei lipase, Rhizomucor miehei aspartic proteinase, Trichoderma reesei beta-glucosidase, Trichoderma reesei cellobiohydrolase I, Trichoderma reesei cellobiohydrolase II, Trichoderma reesei endoglucanase I, Trichoderma reesei endoglucanase II, Trichoderma reesei endoglucanase III, Trichoderma reesei endoglucanase IV, Trichoderma reesei endoglucanase V, Trichoderma reesei xylanase I, Trichoderma reesei xylanase II, Trichoderma reesei beta-xylosidase, as well as the NA2-tpi promoter (a modified promoter from an Aspergillus neutral alpha-amylase gene in which the untranslated leader has been replaced by an untranslated leader from an Aspergillus triose phosphate isomerase gene; non-limiting examples include modified promoters from an Aspergillus niger neutral alpha-amylase gene in which the untranslated leader has been replaced by an untranslated leader from an Aspergillus nidulans or Aspergillus oryzae triose phosphate isomerase gene); and mutant, truncated, and hybrid promoters thereof.

[0285] In a yeast host, useful promoters are obtained from the genes for Saccharomyces cerevisiae enolase (ENO-1), Saccharomyces cerevisiae galactokinase (GAL1), Saccharomyces cerevisiae alcohol dehydrogenase / glyceraldehyde-3-phosphate dehydrogenase (ADH1, ADH2 / GAP), Saccharomyces cerevisiae triose phosphate isomerase (TPI), Saccharomyces cerevisiae metallothionein (CUP1), and Saccharomyces cerevisiae 3-phosphoglycerate kinase. Other useful promoters for yeast host cells are described by Romanos et al., 1992, Yeast 8: 423-488.

[0286] The control sequence may also be a transcription terminator, which is recognized by a host cell to terminate transcription. The terminator sequence is operably linked to the 3'-terminus of the polynucleotide encoding the variant. Any terminator that is functional in the host cell may be used.

[0287] Preferred terminators for bacterial host cells are obtained from the genes for Bacillus clausii alkaline protease (aprH), Bacillus licheniformis alpha-amylase (amyL), and Escherichia coli ribosomal RNA (rrnB).

[0288] Preferred terminators for filamentous fungal host cells are obtained from the genes for Aspergillus nidulans anthranilate synthase, Aspergillus niger glucoamylase, Aspergillus niger alpha-glucosidase, Aspergillus oryzae TAKA amylase, and Fusarium oxysporum trypsin-like protease.

[0289] Preferred terminators for yeast host cells are obtained from the genes for Saccharomyces cerevisiae enolase, Saccharomyces cerevisiae cytochrome C (CYC1), and Saccharomyces cerevisiae glyceraldehyde-3-phosphate dehydrogenase. Other useful terminators for yeast host cells are described by Romanos et al., 1992, supra.

[0290] The control sequence may also be an mRNA stabilizer region downstream of a promoter and upstream of the coding sequence of a gene which increases expression of the gene.

[0291] Examples of suitable mRNA stabilizer regions are obtained from a Bacillus thuringiensis cryIIIA gene (WO 94 / 25612) and a Bacillus subtilis SP82 gene (Hue et al., 1995, Journal of Bacteriology 177: 3465-3471).

[0292] The control sequence may also be a leader, a nontranslated region of an mRNA that is important for translation by the host cell. The leader sequence is operably linked to the 5'-terminus of the polynucleotide encoding the variant. Any leader that is functional in the host cell may be used.

[0293] Preferred leaders for filamentous fungal host cells are obtained from the genes for Aspergillus oryzae TAKA amylase and Aspergillus nidulans triose phosphate isomerase.

[0294] Suitable leaders for yeast host cells are obtained from the genes for Saccharomyces cerevisiae enolase (ENO-1), Saccharomyces cerevisiae 3-phosphoglycerate kinase, Saccharomyces cerevisiae alpha-factor, and Saccharomyces cerevisiae alcohol dehydrogenase / glyceraldehyde-3-phosphate dehydrogenase (ADH2 / GAP).

[0295] The control sequence may also be a polyadenylation sequence, a sequence operably linked to the 3'-terminus of the variant-encoding sequence and, when transcribed, is recognized by the host cell as a signal to add polyadenosine residues to transcribed mRNA. Any polyadenylation sequence that is functional in the host cell may be used.

[0296] Preferred polyadenylation sequences for filamentous fungal host cells are obtained from the genes for Aspergillus nidulans anthranilate synthase, Aspergillus niger glucoamylase, Aspergillus niger alpha-glucosidase, Aspergillus oryzae TAKA amylase, and Fusarium oxysporum trypsin-like protease.

[0297] Useful polyadenylation sequences for yeast host cells are described by Guo and Sherman, 1995, Mol. Cellular Biol. 15: 5983-5990.

[0298] The control sequence may also be a signal peptide coding region that encodes a signal peptide linked to the N-terminus of a variant and directs the variant into the cell's secretory pathway. The 5'-end of the coding sequence of the polynucleotide may inherently contain a signal peptide coding sequence naturally linked in translation reading frame with the segment of the coding sequence that encodes the variant. Alternatively, the 5'-end of the coding sequence may contain a signal peptide coding sequence that is foreign to the coding sequence. A foreign signal peptide coding sequence may be required where the coding sequence does not naturally contain a signal peptide coding sequence. Alternatively, a foreign signal peptide coding sequence may simply replace the natural signal peptide coding sequence in order to enhance secretion of the variant. However, any signal peptide coding sequence that directs the expressed variant into the secretory pathway of a host cell may be used.

[0299] Effective signal peptide coding sequences for bacterial host cells are the signal peptide coding sequences obtained from the genes for Bacillus NCIB 11837 maltogenic amylase, Bacillus licheniformis subtilisin, Bacillus licheniformis beta-lactamase, Bacillus stearothermophilus alpha-amylase, Bacillus stearothermophilus neutral proteases (nprT, nprS, nprM), and Bacillus subtilis prsA. Further signal peptides are described by Simonen and Palva, 1993, Microbiological Reviews 57: 109-137.

[0300] Effective signal peptide coding sequences for filamentous fungal host cells are the signal peptide coding sequences obtained from the genes for Aspergillus niger neutral amylase, Aspergillus niger glucoamylase, Aspergillus oryzae TAKA amylase, Humicola insolens cellulase, Humicola insolens endoglucanase V, Humicola lanuginosa lipase, and Rhizomucor miehei aspartic proteinase.

[0301] Useful signal peptides for yeast host cells are obtained from the genes for Saccharomyces cerevisiae alpha-factor and Saccharomyces cerevisiae invertase. Other useful signal peptide coding sequences are described by Romanos et al., 1992, supra.

[0302] The control sequence may also be a propeptide coding sequence that encodes a propeptide positioned at the N-terminus of a variant. The resultant polypeptide is known as a proenzyme or propolypeptide (or a zymogen in some cases). A propolypeptide is generally inactive and can be converted to an active polypeptide by catalytic or autocatalytic cleavage of the propeptide from the propolypeptide. The propeptide coding sequence may be obtained from the genes for Bacillus subtilis alkaline protease (aprE), Bacillus subtilis neutral protease (nprT), Myceliophthora thermophila laccase (WO 95 / 33836), Rhizomucor miehei aspartic proteinase, and Saccharomyces cerevisiae alpha-factor.

[0303] Where both signal peptide and propeptide sequences are present, the propeptide sequence is positioned next to the N-terminus of the variant and the signal peptide sequence is positioned next to the N-terminus of the propeptide sequence.

[0304] It may also be desirable to add regulatory sequences that regulate expression of the variant relative to the growth of the host cell. Examples of regulatory systems are those that cause expression of the gene to be turned on or off in response to a chemical or physical stimulus, including the presence of a regulatory compound. Regulatory systems in prokaryotic systems include the lac, tac, and trp operator systems. In yeast, the ADH2 system or GAL1 system may be used. In filamentous fungi, the Aspergillus niger glucoamylase promoter, Aspergillus oryzae TAKA alpha-amylase promoter, and Aspergillus oryzae glucoamylase promoter may be used. Other examples of regulatory sequences are those that allow for gene amplification. In eukaryotic systems, these regulatory sequences include the dihydrofolate reductase gene that is amplified in the presence of methotrexate, and the metallothionein genes that are amplified with heavy metals. In these cases, the polynucleotide encoding the variant would be operably linked with the regulatory sequence.Expression Vectors

[0305] The present invention also relates to recombinant expression vectors comprising a polynucleotide encoding a variant of the present invention, a promoter, and transcriptional and translational stop signals. The various nucleotide and control sequences may be joined together to produce a recombinant expression vector that may include one or more convenient restriction sites to allow for insertion or substitution of the polynucleotide encoding the variant at such sites. Alternatively, the polynucleotide may be expressed by inserting the polynucleotide or a nucleic acid construct comprising the polynucleotide into an appropriate vector for expression. In creating the expression vector, the coding sequence is located in the vector so that the coding sequence is operably linked with the appropriate control sequences for expression.

[0306] The recombinant expression vector may be any vector (e.g., a plasmid or virus) that can be conveniently subjected to recombinant DNA procedures and can bring about expression of the polynucleotide. The choice of the vector will typically depend on the compatibility of the vector with the host cell into which the vector is to be introduced. The vector may be a linear or closed circular plasmid.

[0307] The vector may be an autonomously replicating vector, i.e., a vector that exists as an extrachromosomal entity, the replication of which is independent of chromosomal replication, e.g., a plasmid, an extrachromosomal element, a minichromosome, or an artificial chromosome. The vector may contain any means for assuring self-replication. Alternatively, the vector may be one that, when introduced into the host cell, is integrated into the genome and replicated together with the chromosome(s) into which it has been integrated. Furthermore, a single vector or plasmid or two or more vectors or plasmids that together contain the total DNA to be introduced into the genome of the host cell, or a transposon, may be used.

[0308] The vector may contain one or more selectable markers that permit easy selection of transformed, transfected, transduced, or the like cells. A selectable marker is a gene the product of which provides for biocide or viral resistance, resistance to heavy metals, prototrophy to auxotrophs, and the like.

[0309] Examples of bacterial selectable markers are Bacillus licheniformis or Bacillus subtilis dal genes, or markers that confer antibiotic resistance such as ampicillin, chloramphenicol, kanamycin, neomycin, spectinomycin or tetracycline resistance. Suitable markers for yeast host cells include, but are not limited to, ADE2, HIS3, LEU2, LYS2, MET3, TRP1, and URA3. Selectable markers for use in a filamentous fungal host cell include, but are not limited to, amdS (acetamidase), argB (ornithine carbamoyltransferase), bar (phosphinothricin acetyltransferase), hph (hygromycin phosphotransferase), niaD (nitrate reductase), pyrG (orotidine-5'-phosphate decarboxylase), sC (sulfate adenyltransferase), and trpC (anthranilate synthase), as well as equivalents thereof. Preferred for use in an Aspergillus cell are Aspergillus nidulans or Aspergillus oryzae amdS and pyrG genes and a Streptomyces hygroscopicus bar gene.

[0310] The vector may contain an element(s) that permits integration of the vector into the host cell's genome or autonomous replication of the vector in the cell independent of the genome.

[0311] For integration into the host cell genome, the vector may rely on the polynucleotide's sequence encoding the variant or any other element of the vector for integration into the genome by homologous or non-homologous recombination. Alternatively, the vector may contain additional polynucleotides for directing integration by homologous recombination into the genome of the host cell at a precise location(s) in the chromosome(s). To increase the likelihood of integration at a precise location, the integrational elements should contain a sufficient number of nucleic acids, such as 100 to 10,000 base pairs, 400 to 10,000 base pairs, and 800 to 10,000 base pairs, which have a high degree of sequence identity to the corresponding target sequence to enhance the probability of homologous recombination. The integrational elements may be any sequence that is homologous with the target sequence in the genome of the host cell. Furthermore, the integrational elements may be non-encoding or encoding polynucleotides. On the other hand, the vector may be integrated into the genome of the host cell by non-homologous recombination.

[0312] For autonomous replication, the vector may further comprise an origin of replication enabling the vector to replicate autonomously in the host cell in question. The origin of replication may be any plasmid replicator mediating autonomous replication that functions in a cell. The term "origin of replication" or "plasmid replicator" means a polynucleotide that enables a plasmid or vector to replicate in vivo.

[0313] Examples of bacterial origins of replication are the origins of replication of plasmids pBR322, pUC19, pACYC177, and pACYC184 permitting replication in E. coli, and pUB110, pE194, pTA1060, and pAMβ1 permitting replication in Bacillus.

[0314] Examples of origins of replication for use in a yeast host cell are the 2 micron origin of replication, ARS1, ARS4, the combination of ARS1 and CEN3, and the combination of ARS4 and CEN6.

[0315] Examples of origins of replication useful in a filamentous fungal cell are AMA1 and ANS1 (Gems et al., 1991, Gene 98: 61-67; Cullen et al., 1987, Nucleic Acids Res. 15: 9163-9175; WO 00 / 24883). Isolation of the AMA1 gene and construction of plasmids or vectors comprising the gene can be accomplished according to the methods disclosed in WO 00 / 24883.

[0316] More than one copy of a polynucleotide of the present invention may be inserted into a host cell to increase production of a variant. An increase in the copy number of the polynucleotide can be obtained by integrating at least one additional copy of the sequence into the host cell genome or by including an amplifiable selectable marker gene with the polynucleotide where cells containing amplified copies of the selectable marker gene, and thereby additional copies of the polynucleotide, can be selected for by cultivating the cells in the presence of the appropriate selectable agent.

[0317] The procedures used to ligate the elements described above to construct the recombinant expression vectors of the present invention are well known to one skilled in the art (see, e.g., Sambrook et al., 1989, supra).Host Cells

[0318] The present invention also relates to recombinant host cells, comprising a polynucleotide encoding a variant of the present invention operably linked to one or more control sequences that direct the production of a variant of the present invention. A construct or vector comprising a polynucleotide is introduced into a host cell so that the construct or vector is maintained as a chromosomal integrant or as a self-replicating extra-chromosomal vector as described earlier. The term "host cell" encompasses any progeny of a parent cell that is not identical to the parent cell due to mutations that occur during replication. The choice of a host cell will to a large extent depend upon the gene encoding the variant and its source.

[0319] The host cell may be any cell useful in the recombinant production of a variant, e.g., a prokaryote or a eukaryote.

[0320] The prokaryotic host cell may be any Gram-positive or Gram-negative bacterium. Gram-positive bacteria include, but are not limited to, Bacillus, Clostridium, Enterococcus, Geobacillus, Lactobacillus, Lactococcus, Oceanobacillus, Staphylococcus, Streptococcus, and Streptomyces. Gram-negative bacteria include, but are not limited to, Campylobacter, E. coli, Flavobacterium, Fusobacterium, Helicobacter, Ilyobacter, Neisseria, Pseudomonas, Salmonella, and Ureaplasma.

[0321] The bacterial host cell may be any Bacillus cell including, but not limited to, Bacillus alkalophilus, Bacillus amyloliquefaciens, Bacillus brevis, Bacillus circulans, Bacillus clausii, Bacillus coagulans, Bacillus firmus, Bacillus lautus, Bacillus lentus, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus stearothermophilus, Bacillus subtilis, and Bacillus thuringiensis cells.

[0322] The bacterial host cell may also be any Streptococcus cell including, but not limited to, Streptococcus equisimilis, Streptococcus pyogenes, Streptococcus uberis, and Streptococcus equi subsp. Zooepidemicus cells.

[0323] The bacterial host cell may also be any Streptomyces cell, including, but not limited to, Streptomyces achromogenes, Streptomyces avermitilis, Streptomyces coelicolor, Streptomyces griseus, and Streptomyces lividans cells.

[0324] The introduction of DNA into a Bacillus cell may be effected by protoplast transformation (see, e.g., Chang and Cohen, 1979, Mol. Gen. Genet. 168: 111-115), competent cell transformation (see, e.g., Young and Spizizen, 1961, J. Bacteriol. 81: 823-829, or Dubnau and Davidoff-Abelson, 1971, J. Mol. Biol. 56: 209-221), electroporation (see, e.g., Shigekawa and Dower, 1988, Biotechniques 6: 742-751), or conjugation (see, e.g., Koehler and Thorne, 1987, J. Bacteriol. 169: 5271-5278). The introduction of DNA into an E. coli cell may be effected by protoplast transformation (see, e.g., Hanahan, 1983, J. Mol. Biol. 166: 557-580) or electroporation (see, e.g., Dower et al., 1988, Nucleic Acids Res. 16: 6127-6145). The introduction of DNA into a Streptomyces cell may be effected by protoplast transformation, electroporation (see, e.g., Gong et al., 2004, Folia Microbiol. (Praha) 49: 399-405), conjugation (see, e.g., Mazodier et al., 1989, J. Bacteriol. 171: 3583-3585), or transduction (see, e.g., Burke et al., 2001, Proc. Natl. Acad. Sci. USA 98: 6289-6294). The introduction of DNA into a Pseudomonas cell may be effected by electroporation (see, e.g., Choi et al., 2006, J. Microbiol. Methods 64: 391-397), or conjugation (see, e.g., Pinedo and Smets, 2005, Appl. Environ. Microbiol. 71: 51-57). The introduction of DNA into a Streptococcus cell may be effected by natural competence (see, e.g., Perry and Kuramitsu, 1981, Infect. Immun. 32: 1295-1297), protoplast transformation (see, e.g., Catt and Jollick, 1991, Microbios 68: 189-207), electroporation (see, e.g., Buckley et al., 1999, Appl. Environ. Microbiol. 65: 3800-3804) or conjugation (see, e.g., Clewell, 1981, Microbiol. Rev. 45: 409-436). However, any method known in the art for introducing DNA into a host cell can be used.

[0325] The host cell may also be a eukaryote, such as a mammalian, insect, plant, or fungal cell.

[0326] The host cell may be a fungal cell. "Fungi" as used herein includes the phyla Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota as well as the Oomycota and all mitosporic fungi (as defined by Hawksworth et al., In, Ainsworth and Bisby's Dictionary of The Fungi, 8th edition, 1995, CAB International, University Press, Cambridge, UK).

[0327] The fungal host cell may be a yeast cell. "Yeast" as used herein includes ascosporogenous yeast (Endomycetales), basidiosporogenous yeast, and yeast belonging to the Fungi Imperfecti (Blastomycetes). Since the classification of yeast may change in the future, for the purposes of this invention, yeast shall be defined as described in Biology and Activities of Yeast (Skinner, Passmore, and Davenport, editors, Soc. App. Bacteriol. Symposium Series No. 9, 1980).

[0328] The yeast host cell may be a Candida, Hansenula, Kluyveromyces, Pichia, Saccharomyces, Schizosaccharomyces, or Yarrowia cell such as a Kluyveromyces lactis, Saccharomyces carlsbergensis, Saccharomyces cerevisiae, Saccharomyces diastaticus, Saccharomyces douglasii, Saccharomyces kluyveri, Saccharomyces norbensis, Saccharomyces oviformis, or Yarrowia lipolytica cell.

[0329] The fungal host cell may be a filamentous fungal cell. "Filamentous fungi" include all filamentous forms of the subdivision Eumycota and Oomycota (as defined by Hawksworth et al., 1995, supra). The filamentous fungi are generally characterized by a mycelial wall composed of chitin, cellulose, glucan, chitosan, mannan, and other complex polysaccharides. Vegetative growth is by hyphal elongation and carbon catabolism is obligately aerobic. In contrast, vegetative growth by yeasts such as Saccharomyces cerevisiae is by budding of a unicellular thallus and carbon catabolism may be fermentative.

[0330] The filamentous fungal host cell may be an Acremonium, Aspergillus, Aureobasidium, Bjerkandera, Ceriporiopsis, Chrysosporium, Coprinus, Coriolus, Cryptococcus, Filibasidium, Fusarium, Humicola, Magnaporthe, Mucor, Myceliophthora, Neocallimastix, Neurospora, Paecilomyces, Penicillium, Phanerochaete, Phlebia, Piromyces, Pleurotus, Schizophyllum, Talaromyces, Thermoascus, Thielavia, Tolypocladium, Trametes, or Trichoderma cell.

[0331] For example, the filamentous fungal host cell may be an Aspergillus awamori, Aspergillus foetidus, Aspergillus fumigatus, Aspergillus japonicus, Aspergillus nidulans, Aspergillus niger, Aspergillus oryzae, Bjerkandera adusta, Ceriporiopsis aneirina, Ceriporiopsis caregiea, Ceriporiopsis gilvescens, Ceriporiopsis pannocinta, Ceriporiopsis rivulosa, Ceriporiopsis subrufa, Ceriporiopsis subvermispora, Chrysosporium inops, Chrysosporium keratinophilum, Chrysosporium lucknowense, Chrysosporium merdarium, Chrysosporium pannicola, Chrysosporium queenslandicum, Chrysosporium tropicum, Chrysosporium zonatum, Coprinus cinereus, Coriolus hirsutus, Fusarium bactridioides, Fusarium cerealis, Fusarium crookwellense, Fusarium culmorum, Fusarium graminearum, Fusarium graminum, Fusarium heterosporum, Fusarium negundi, Fusarium oxysporum, Fusarium reticulatum, Fusarium roseum, Fusarium sambucinum, Fusarium sarcochroum, Fusarium sporotrichioides, Fusarium sulphureum, Fusarium torulosum, Fusarium trichothecioides, Fusarium venenatum, Humicola insolens, Humicola lanuginosa, Mucor miehei, Myceliophthora thermophila, Neurospora crassa, Penicillium purpurogenum, Phanerochaete chrysosporium, Phlebia radiata, Pleurotus eryngii, Thielavia terrestris, Trametes villosa, Trametes versicolor, Trichoderma harzianum, Trichoderma koningii, Trichoderma longibrachiatum, Trichoderma reesei, or Trichoderma viride cell.

[0332] Fungal cells may be transformed by a process involving protoplast formation, transformation of the protoplasts, and regeneration of the cell wall in a manner known per se. Suitable procedures for transformation of Aspergillus and Trichoderma host cells are described in EP 238023, Yelton et al., 1984, Proc. Natl. Acad. Sci. USA 81: 1470-1474, and Christensen et al., 1988, Bio / Technology 6: 1419-1422. Suitable methods for transforming Fusarium species are described by Malardier et al., 1989, Gene 78: 147-156, and WO 96 / 00787. Yeast may be transformed using the procedures described by Becker and Guarente, In Abelson, J.N. and Simon, M.I., editors, Guide to Yeast Genetics and Molecular Biology, Methods in Enzymology, Volume 194, pp 182-187, Academic Press, Inc., New York; Ito et al., 1983, J. Bacteriol. 153: 163; and Hinnen et al., 1978, Proc. Natl. Acad. Sci. USA 75: 1920.Methods of Production

[0333] The present invention also relates to a method of producing the xylanase variant of the invention, comprising: (a) cultivating the recombinant host cell of the invention under conditions conducive for production of the polypeptide; and (b) recovering the polypeptide.

[0334] The host cells are cultivated in a nutrient medium suitable for production of the variant using methods known in the art. For example, the cell may be cultivated by shake flask cultivation, or small-scale or large-scale fermentation (including continuous, batch, fed-batch, or solid state fermentations) in laboratory or industrial fermentors performed in a suitable medium and under conditions allowing the variant to be expressed and / or isolated. The cultivation takes place in a suitable nutrient medium comprising carbon and nitrogen sources and inorganic salts, using procedures known in the art. Suitable media are available from commercial suppliers or may be prepared according to published compositions (e.g., in catalogues of the American Type Culture Collection). If the variant is secreted into the nutrient medium, the variant can be recovered directly from the medium. If the variant is not secreted, it can be recovered from cell lysates.

[0335] The variant may be detected using methods known in the art that are specific for the variants. These detection methods include, but are not limited to, use of specific antibodies, formation of an enzyme product, or disappearance of an enzyme substrate. For example, an enzyme assay may be used to determine the activity of the variant.

[0336] The variant may be recovered using methods known in the art. For example, the variant may be recovered from the nutrient medium by conventional procedures including, but not limited to, collection, centrifugation, filtration, extraction, spray-drying, evaporation, or precipitation.

[0337] The variant may be purified by a variety of procedures known in the art including, but not limited to, chromatography (e.g., ion exchange, affinity, hydrophobic, chromatofocusing, and size exclusion), electrophoretic procedures (e.g., preparative isoelectric focusing), differential solubility (e.g., ammonium sulfate precipitation), SDS-PAGE, or extraction (see, e.g., Protein Purification, Janson and Ryden, editors, VCH Publishers, New York, 1989) to obtain substantially pure variants.

[0338] In an alternative aspect, the variant is not recovered, but rather a host cell of the present invention expressing the variant is used as a source of the variant.Fermentation Broth Formulations or Cell Compositions

[0339] The present invention also relates to a fermentation broth formulation or a cell composition comprising a polypeptide of the present invention. The fermentation broth product further comprises additional ingredients used in the fermentation process, such as, for example, cells (including, the host cells containing the gene encoding the polypeptide of the present invention which are used to produce the polypeptide of interest), cell debris, biomass, fermentation media and / or fermentation products. In some embodiments, the composition is a cell-killed whole broth containing organic acid(s), killed cells and / or cell debris, and culture medium.

[0340] The term "fermentation broth" as used herein refers to a preparation produced by cellular fermentation that undergoes no or minimal recovery and / or purification. For example, fermentation broths are produced when microbial cultures are grown to saturation, incubated under carbon-limiting conditions to allow protein synthesis (e.g., expression of enzymes by host cells) and secretion into cell culture medium. The fermentation broth can contain unfractionated or fractionated contents of the fermentation materials derived at the end of the fermentation. Typically, the fermentation broth is unfractionated and comprises the spent culture medium and cell debris present after the microbial cells (e.g., filamentous fungal cells) are removed, e.g., by centrifugation. In some embodiments, the fermentation broth contains spent cell culture medium, extracellular enzymes, and viable and / or nonviable microbial cells.

[0341] In an embodiment, the fermentation broth formulation and cell compositions comprise a first organic acid component comprising at least one 1-5 carbon organic acid and / or a salt thereof and a second organic acid component comprising at least one 6 or more carbon organic acid and / or a salt thereof. In a specific embodiment, the first organic acid component is acetic acid, formic acid, propionic acid, a salt thereof, or a mixture of two or more of the foregoing and the second organic acid component is benzoic acid, cyclohexanecarboxylic acid, 4-methylvaleric acid, phenylacetic acid, a salt thereof, or a mixture of two or more of the foregoing.

[0342] In one aspect, the composition contains an organic acid(s), and optionally further contains killed cells and / or cell debris. In one embodiment, the killed cells and / or cell debris are removed from a cell-killed whole broth to provide a composition that is free of these components.

[0343] The fermentation broth formulations or cell compositions may further comprise a preservative and / or anti-microbial (e.g., bacteriostatic) agent, including, but not limited to, sorbitol, sodium chloride, potassium sorbate, and others known in the art.

[0344] The cell-killed whole broth or composition may contain the unfractionated contents of the fermentation materials derived at the end of the fermentation. Typically, the cell-killed whole broth or composition contains the spent culture medium and cell debris present after the microbial cells (e.g., filamentous fungal cells) are grown to saturation, incubated under carbon-limiting conditions to allow protein synthesis. In some embodiments, the cell-killed whole broth or composition contains the spent cell culture medium, extracellular enzymes, and killed filamentous fungal cells. In some embodiments, the microbial cells present in the cell-killed whole broth or composition can be permeabilized and / or lysed using methods known in the art.

[0345] A whole broth or cell composition as described herein is typically a liquid, but may contain insoluble components, such as killed cells, cell debris, culture media components, and / or insoluble enzyme(s). In some embodiments, insoluble components may be removed to provide a clarified liquid composition.

[0346] The whole broth formulations and cell compositions of the present invention may be produced by a method described in WO 90 / 15861 or WO 2010 / 096673.Enzyme Compositions

[0347] The present invention also relates to compositions comprising a variant of the present invention and a formulating agent. Preferably, the compositions are enriched in the polypeptide of the invention. The term "enriched" indicates that the xylanase activity of the composition has been increased, e.g., with an enrichment factor of at least 1.1, such as at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 2.0, at least 3.0, at least 4.0, at least 5.0, at least 10.

[0348] The compositions may further comprise multiple enzymatic activities, such as one or more (e.g., several) enzymes selected from the group consisting of acetylxylan esterase, acylglycerol lipase, amylase, alpha-amylase, beta-amylase, arabinofuranosidase, cellobiohydrolases, cellulase, feruloyl esterase, galactanase, alpha-galactosidase, beta-galactosidase, beta-glucanase, beta-glucosidase, glucan 1,4-a-glucosidase, glucan 1,4-alpha-maltohydrolase, glucan 1,4-a-glucosidase, glucan 1,4-alpha-maltohydrolase, lysophospholipase, lysozyme, alpha-mannosidase, beta-mannosidase (mannanase), phytase, phospholipase A1, phospholipase A2, phospholipase D, protease, pullulanase, pectinesterase, triacylglycerol lipase, xylanase, beta-xylosidase or any combination thereof.

[0349] The compositions may further comprise one or more microbes. In an embodiment, the microbe is selected from the group consisting of Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus cereus, Bacillus pumilus, Bacillus polymyxa, Bacillus megaterium, Bacillus coagulans, Bacillus circulans, Bifidobacterium bifidum, Bifidobacterium animalis, Bifidobacterium sp., Carnobacterium sp., Clostridium butyricum, Clostridium sp., Enterococcus faecium, Enterococcus sp., Lactobacillus sp., Lactobacillus acidophilus, Lactobacillus farciminus, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus salivarius, Lactococcus lactis, Lactococcus sp., Leuconostoc sp., Megasphaera elsdenii, Megasphaera sp., Pediococsus acidilactici, Pediococcus sp., Propionibacterium thoenii, Propionibacterium sp. and Streptococcus sp. or any combination thereof.

[0350] The composition comprises one or more formulating agents as disclosed herein, preferably one or more of the compounds selected from the list consisting of glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch, kaolin and cellulose.

[0351] In an embodiment, the composition comprises one or more components selected from the list consisting of vitamins, minerals and amino acids.

[0352] In an embodiment, the composition comprises plant based material from the sub-family Panicoideae as disclosed herein, preferably maize, corn, sorghum, switchgrass, millet, pearl millet, foxtail millet or in a processed form such as milled corn, milled maize, defatted maize, defatted destarched maize, milled sorghum, milled switchgrass, milled millet, milled foxtail millet, milled pearl millet, or any combination thereof.Formulation

[0353] The enzyme of the invention may be formulated as a liquid or a solid. For a liquid formulation, the formulating agent may comprise a polyol (such as e.g. glycerol, ethylene glycol or propylene glycol), a salt (such as e.g. sodium chloride, sodium benzoate, potassium sorbate) or a sugar or sugar derivative (such as e.g. dextrin, glucose, sucrose, and sorbitol). Thus in one embodiment, the composition is a liquid composition comprising the polypeptide of the invention and one or more formulating agents selected from the list consisting of glycerol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, dextrin, glucose, sucrose, and sorbitol. The liquid formulation may be sprayed onto the feed after it has been pelleted or may be added to drinking water given to the animals.

[0354] For a solid formulation, the formulation may be for example as a granule, spray dried powder or agglomerate (e.g. as disclosed in WO2000 / 70034). The formulating agent may comprise a salt (organic or inorganic zinc, sodium, potassium or calcium salts such as e.g. such as calcium acetate, calcium benzoate, calcium carbonate, calcium chloride, calcium citrate, calcium sorbate, calcium sulfate, potassium acetate, potassium benzoate, potassium carbonate, potassium chloride, potassium citrate, potassium sorbate, potassium sulfate, sodium acetate, sodium benzoate, sodium carbonate, sodium chloride, sodium citrate, sodium sulfate, zinc acetate, zinc benzoate, zinc carbonate, zinc chloride, zinc citrate, zinc sorbate, zinc sulfate), starch or a sugar or sugar derivative (such as e.g. sucrose, dextrin, glucose, lactose, sorbitol).

[0355] In one embodiment, the composition is a solid composition, such as a spray dried composition, comprising the xylanase of the invention and one or more formulating agents selected from the list consisting of sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch and cellulose. In a preferred embodiment, the formulating agent is selected from one or more of the following compounds: sodium sulfate, dextrin, cellulose, sodium thiosulfate, magnesium sulfate and calcium carbonate.

[0356] The present invention also relates to enzyme granules / particles comprising the xylanase of the invention optionally combined with one or more additional enzymes. The granule is composed of a core, and optionally one or more coatings (outer layers) surrounding the core.

[0357] Typically the granule / particle size, measured as equivalent spherical diameter (volume based average particle size), of the granule is 20-2000 µm, particularly 50-1500 µm, 100-1500 µm or 250-1200 µm.

[0358] The core can be prepared by granulating a blend of the ingredients, e.g., by a method comprising granulation techniques such as crystallization, precipitation, pan-coating, fluid bed coating, fluid bed agglomeration, rotary atomization, extrusion, prilling, spheronization, size reduction methods, drum granulation, and / or high shear granulation.

[0359] Methods for preparing the core can be found in Handbook of Powder Technology; Particle size enlargement by C. E. Capes; Volume 1; 1980; Elsevier. Preparation methods include known feed and granule formulation technologies, e.g.: a) spray dried products, wherein a liquid enzyme-containing solution is atomized in a spray drying tower to form small droplets which during their way down the drying tower dry to form an enzyme-containing particulate material; b) layered products, wherein the enzyme is coated as a layer around a pre-formed inert core particle, wherein an enzyme-containing solution is atomized, typically in a fluid bed apparatus wherein the pre-formed core particles are fluidized, and the enzyme-containing solution adheres to the core particles and dries up to leave a layer of dry enzyme on the surface of the core particle. Particles of a desired size can be obtained this way if a useful core particle of the desired size can be found. This type of product is described in, e.g., WO 97 / 23606; c) absorbed core particles, wherein rather than coating the enzyme as a layer around the core, the enzyme is absorbed onto and / or into the surface of the core. Such a process is described in WO 97 / 39116. d) extrusion or pelletized products, wherein an enzyme-containing paste is pressed to pellets or under pressure is extruded through a small opening and cut into particles which are subsequently dried. Such particles usually have a considerable size because of the material in which the extrusion opening is made (usually a plate with bore holes) sets a limit on the allowable pressure drop over the extrusion opening. Also, very high extrusion pressures when using a small opening increase heat generation in the enzyme paste, which is harmful to the enzyme; e) prilled products, wherein an enzyme-containing powder is suspended in molten wax and the suspension is sprayed, e.g., through a rotating disk atomiser, into a cooling chamber where the droplets quickly solidify (Michael S. Showell (editor); Powdered detergents; Surfactant Science Series; 1998; vol. 71; page 140-142; Marcel Dekker). The product obtained is one wherein the enzyme is uniformly distributed throughout an inert material instead of being concentrated on its surface. Also US 4,016,040 and US 4,713,245 are documents relating to this technique; f) mixer granulation products, wherein a liquid is added to a dry powder composition of, e.g., conventional granulating components, the enzyme being introduced either via the liquid or the powder or both. The liquid and the powder are mixed and as the moisture of the liquid is absorbed in the dry powder, the components of the dry powder will start to adhere and agglomerate and particles will build up, forming granulates comprising the enzyme. Such a process is described in US 4,106,991 and related documents EP 170360, EP 304332, EP 304331, WO 90 / 09440 and WO 90 / 09428. In a particular product of this process wherein various high-shear mixers can be used as granulators, granulates consisting of enzyme as enzyme, fillers and binders etc. are mixed with cellulose fibres to reinforce the particles to give the so-called T-granulate. Reinforced particles, being more robust, release less enzymatic dust. g) size reduction, wherein the cores are produced by milling or crushing of larger particles, pellets, tablets, briquettes etc. containing the enzyme. The wanted core particle fraction is obtained by sieving the milled or crushed product. Over and undersized particles can be recycled. Size reduction is described in (Martin Rhodes (editor); Principles of Powder Technology; 1990; Chapter 10; John Wiley & Sons); h) fluid bed granulation, which involves suspending particulates in an air stream and spraying a liquid onto the fluidized particles via nozzles. Particles hit by spray droplets get wetted and become tacky. The tacky particles collide with other particles and adhere to them and form a granule; i) the cores may be subjected to drying, such as in a fluid bed drier. Other known methods for drying granules in the feed or detergent industry can be used by the skilled person. The drying preferably takes place at a product temperature of from 25 to 90°C. For some enzymes it is important the cores comprising the enzyme contain a low amount of water before coating. If water sensitive enzymes are coated before excessive water is removed, it will be trapped within the core and it may affect the activity of the enzyme negatively. After drying, the cores preferably contain 0.1-10 % w / w water.

[0360] The core may include additional materials such as fillers, fibre materials (cellulose or synthetic fibres), stabilizing agents, solubilizing agents, suspension agents, viscosity regulating agents, light spheres, plasticizers, salts, lubricants and fragrances.

[0361] The core may include a binder, such as synthetic polymer, wax, fat, or carbohydrate.

[0362] The core may include a salt of a multivalent cation, a reducing agent, an antioxidant, a peroxide decomposing catalyst and / or an acidic buffer component, typically as a homogenous blend.

[0363] In one embodiment, the core comprises a material selected from the group consisting of salts (such as calcium acetate, calcium benzoate, calcium carbonate, calcium chloride, calcium citrate, calcium sorbate, calcium sulfate, potassium acetate, potassium benzoate, potassium carbonate, potassium chloride, potassium citrate, potassium sorbate, potassium sulfate, sodium acetate, sodium benzoate, sodium carbonate, sodium chloride, sodium citrate, sodium sulfate, zinc acetate, zinc benzoate, zinc carbonate, zinc chloride, zinc citrate, zinc sorbate, zinc sulfate), starch or a sugar or sugar derivative (such as e.g. sucrose, dextrin, glucose, lactose, sorbitol), sugar or sugar derivative (such as e.g. sucrose, dextrin, glucose, lactose, sorbitol), small organic molecules, starch, flour, cellulose and minerals and clay minerals (also known as hydrous aluminium phyllosilicates). In one embodiment, the core comprises a clay mineral such as kaolinite or kaolin.

[0364] The core may include an inert particle with the enzyme absorbed into it, or applied onto the surface, e.g., by fluid bed coating.

[0365] The core may have a diameter of 20-2000 µm, particularly 50-1500 µm, 100-1500 µm or 250-1200 µm.

[0366] The core may be surrounded by at least one coating, e.g., to improve the storage stability, to reduce dust formation during handling, or for coloring the granule. The optional coating(s) may include a salt and / or wax and / or flour coating, or other suitable coating materials.

[0367] The coating may be applied in an amount of at least 0.1% by weight of the core, e.g., at least 0.5%, 1% or 5%. The amount may be at most 100%, 70%, 50%, 40% or 30%.

[0368] The coating is preferably at least 0.1 µm thick, particularly at least 0.5 µm, at least 1 µm or at least 5 µm. In some embodiments the thickness of the coating is below 100 µm, such as below 60 µm, or below 40 µm.

[0369] The coating should encapsulate the core unit by forming a substantially continuous layer. A substantially continuous layer is to be understood as a coating having few or no holes, so that the core unit is encapsulated or enclosed with few or no uncoated areas. The layer or coating should in particular be homogeneous in thickness.

[0370] The coating can further contain other materials as known in the art, e.g., fillers, antisticking agents, pigments, dyes, plasticizers and / or binders, such as titanium dioxide, kaolin, calcium carbonate or talc.

[0371] A salt coating may comprise at least 60% by weight of a salt, e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99% by weight.

[0372] The salt may be added from a salt solution where the salt is completely dissolved or from a salt suspension wherein the fine particles are less than 50 µm, such as less than 10 µm or less than 5 µm.

[0373] The salt coating may comprise a single salt or a mixture of two or more salts. The salt may be water soluble, in particular having a solubility at least 0.1 g in 100 g of water at 20°C, preferably at least 0.5 g per 100 g water, e.g., at least 1 g per 100 g water, e.g., at least 5 g per 100 g water.

[0374] The salt may be an inorganic salt, e.g., salts of sulfate, sulfite, phosphate, phosphonate, nitrate, chloride or carbonate or salts of simple organic acids (less than 10 carbon atoms, e.g., 6 or less carbon atoms) such as citrate, malonate or acetate. Examples of cations in these salts are alkali or earth alkali metal ions, the ammonium ion or metal ions of the first transition series, such as sodium, potassium, magnesium, calcium, zinc or aluminium. Examples of anions include chloride, bromide, iodide, sulfate, sulfite, bisulfite, thiosulfate, phosphate, monobasic phosphate, dibasic phosphate, hypophosphite, dihydrogen pyrophosphate, tetraborate, borate, carbonate, bicarbonate, metasilicate, citrate, malate, maleate, malonate, succinate, sorbate, lactate, formate, acetate, butyrate, propionate, benzoate, tartrate, ascorbate or gluconate. In particular alkali- or earth alkali metal salts of sulfate, sulfite, phosphate, phosphonate, nitrate, chloride or carbonate or salts of simple organic acids such as citrate, malonate or acetate may be used.

[0375] The salt in the coating may have a constant humidity at 20°C above 60%, particularly above 70%, above 80% or above 85%, or it may be another hydrate form of such a salt (e.g., anhydrate). The salt coating may be as described in WO1997 / 05245, WO1998 / 54980, WO1998 / 55599, WO2000 / 70034, WO2006 / 034710, WO2008 / 017661, WO2008 / 017659, WO2000 / 020569, WO2001 / 004279, WO1997 / 05245, WO2000 / 01793, WO2003 / 059086, WO2003 / 059087, WO2007 / 031483, WO2007 / 031485, WO2007 / 044968, WO2013 / 192043, WO2014 / 014647 and WO2015 / 197719 or polymer coating such as described in WO 2001 / 00042.

[0376] Specific examples of suitable salts are NaCl (CH20°C=76%), Na2CO3 (CH20°C=92%), NaNO3 (CH20°C=73%), Na2HPO4 (CH20°C=95%), Na3PO4 (CH25°C=92%), NH4CI (CH20°C = 79.5%), (NH4)2HPO4 (CH20°C = 93,0%), NH4H2PO4 (CH20°C = 93.1%), (NH4)2SO4 (CH20°C=81.1%), KCI (CH20°C=85%), K2HPO4 (CH20°C=92%), KH2PO4 (CH20°C=96.5%), KNO3 (CH20°C=93.5%), Na2SO4 (CH20°C=93%), K2SO4 (CH20°C=98%), KHSO4 (CH20°C=86%), MgSO4 (CH20°C=90%), ZnSO4 (CH20°C=90%) and sodium citrate (CH25°C=86%). Other examples include NaH2PO4, (NH4)H2PO4, CuSO4, Mg(NO3)2, magnesium acetate, calcium acetate, calcium benzoate, calcium carbonate, calcium chloride, calcium citrate, calcium sorbate, calcium sulfate, potassium acetate, potassium benzoate, potassium carbonate, potassium chloride, potassium citrate, potassium sorbate, sodium acetate, sodium benzoate, sodium citrate, sodium sulfate, zinc acetate, zinc benzoate, zinc carbonate, zinc chloride, zinc citrate and zinc sorbate.

[0377] The salt may be in anhydrous form, or it may be a hydrated salt, i.e. a crystalline salt hydrate with bound water(s) of crystallization, such as described in WO 99 / 32595. Specific examples include anhydrous sodium sulfate (Na2SO4), anhydrous magnesium sulfate (MgSO4), magnesium sulfate heptahydrate (MgSO4.7H2O), zinc sulfate heptahydrate (ZnSO4.7H2O), sodium phosphate dibasic heptahydrate (Na2HPO4.7H2O), magnesium nitrate hexahydrate (Mg(NO3)2(6H2O)), sodium citrate dihydrate and magnesium acetate tetrahydrate.

[0378] Preferably the salt is applied as a solution of the salt, e.g., using a fluid bed.

[0379] A wax coating may comprise at least 60% by weight of a wax, e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99% by weight.

[0380] Specific examples of waxes are polyethylene glycols; polypropylenes; Carnauba wax; Candelilla wax; bees wax; hydrogenated plant oil or animal tallow such as polyethylene glycol (PEG), methyl hydroxy-propyl cellulose (MHPC), polyvinyl alcohol (PVA), hydrogenated ox tallow, hydrogenated palm oil, hydrogenated cotton seeds and / or hydrogenated soy bean oil; fatty acid alcohols; mono-glycerides and / or di-glycerides, such as glyceryl stearate, wherein stearate is a mixture of stearic and palmitic acid; micro-crystalline wax; paraffin's; and fatty acids, such as hydrogenated linear long chained fatty acids and derivatives thereof. A preferred wax is palm oil or hydrogenated palm oil.

[0381] The granule may comprise a core comprising the xylanase of the invention, one or more salt coatings and one or more wax coatings. Examples of enzyme granules with multiple coatings are shown in WO1993 / 07263, WO1997 / 23606 and WO2016 / 149636.

[0382] Non-dusting granulates may be produced, e.g., as disclosed in U.S. Patent Nos. 4,106,991 and 4,661,452 and may optionally be coated by methods known in the art. The coating materials can be waxy coating materials and film-forming coating materials. Examples of waxy coating materials are poly(ethylene oxide) products (polyethyleneglycol, PEG) with mean molar weights of 1000 to 20000; ethoxylated nonylphenols having from 16 to 50 ethylene oxide units; ethoxylated fatty alcohols in which the alcohol contains from 12 to 20 carbon atoms and in which there are 15 to 80 ethylene oxide units; fatty alcohols; fatty acids; and mono- and di- and triglycerides of fatty acids. Examples of film-forming coating materials suitable for application by fluid bed techniques are given in GB 1483591.

[0383] The granulate may further comprise one or more additional enzymes. Each enzyme will then be present in more granules securing a more uniform distribution of the enzymes, and also reduces the physical segregation of different enzymes due to different particle sizes. Methods for producing multi-enzyme co-granulates is disclosed in the ip.com disclosure IPCOM000200739D.

[0384] Another example of formulation of enzymes by the use of co-granulates is disclosed in WO 2013 / 188331.

[0385] The present invention also relates to protected enzymes prepared according to the method disclosed in EP 238,216.

[0386] Thus, in a further aspect, the present invention provides a granule, which comprises: (a) a core comprising an xylanase according to the invention, and (b) a coating consisting of one or more layer(s) surrounding the core.

[0387] In one embodiment, the coating comprises a salt coating as described herein. In one embodiment, the coating comprises a wax coating as described herein. In one embodiment, the coating comprises a salt coating followed by a wax coating as described herein.Animal Feed Additives

[0388] The present invention also relates to animal feed compositions and animal feed additives comprising one or more xylanases of the invention. In an embodiment, the animal feed or animal feed additive comprises a formulating agent and one or more xylanases of the invention. In a further embodiment, the formulating agent comprises one or more of the following compounds: glycerol, ethylene glycol, 1, 2-propylene glycol or 1, 3-propylene glycol, sodium chloride, sodium benzoate, potassium sorbate, sodium sulfate, potassium sulfate, magnesium sulfate, sodium thiosulfate, calcium carbonate, sodium citrate, dextrin, glucose, sucrose, sorbitol, lactose, starch and cellulose.

[0389] Thus the invention further relates to an animal feed additive comprising one or more vitamins and a xylanase variant of the invention. The invention also relates to an animal feed additive comprising one or more minerals and a xylanase variant of the invention. The invention also relates to an animal feed additive comprising one or more amino acids and a xylanase variant of the invention.

[0390] In an embodiment, the amount of enzyme in the animal feed additive is between 0.001% and 10% by weight of the composition.

[0391] In an embodiment, the animal feed additive comprises one or more formulating agents, preferably as described herein above.

[0392] In an embodiment, the animal feed additive comprises one or more additional enzymes, preferably as described herein below.

[0393] In an embodiment, the animal feed additive comprises one or more probiotics, preferably as described herein below.

[0394] In an embodiment, the animal feed additive comprises one or more vitamins, preferably as described herein below.

[0395] In an embodiment, the animal feed additive comprises one or more minerals, preferably as described herein below.

[0396] In an embodiment, the animal feed additive comprises one or more amino acids, preferably as described herein below.

[0397] In an embodiment, the animal feed additive comprises one or more prebiotics, preferably as described herein below.

[0398] In an embodiment, the animal feed additive comprises one or more organic acids, preferably as described herein below.

[0399] In an embodiment, the animal feed additive comprises one or more phytogenics, preferably as described herein below.Animal Feed

[0400] The present invention also relates to animal feed compositions comprising one or more xylanase variants of the invention. The invention also relates to an animal feed comprising the granule as described herein and plant based material. The invention also relates to an animal feed comprising the animal feed additive as described herein and plant based material. In one embodiment, the plant based material is from the sub-family Panicoideae.

[0401] Animal feed compositions or diets have a relatively high content of protein. Poultry and pig diets can be characterised as indicated in Table B of WO 01 / 58275, columns 2-3. Fish diets can be characterised as indicated in column 4 of this Table B. Furthermore such fish diets usually have a crude fat content of 200-310 g / kg.

[0402] An animal feed composition according to the invention has a crude protein content of 50-800 g / kg, and furthermore comprises at least one xylanase as claimed herein.

[0403] Furthermore, or in the alternative (to the crude protein content indicated above), the animal feed composition of the invention has a content of metabolisable energy of 10-30 MJ / kg; and / or a content of calcium of 0.1-200 g / kg; and / or a content of available phosphorus of 0.1-200 g / kg; and / or a content of methionine of 0.1-100 g / kg; and / or a content of methionine plus cysteine of 0.1-150 g / kg; and / or a content of lysine of 0.5-50 g / kg.

[0404] In particular embodiments, the content of metabolisable energy, crude protein, calcium, phosphorus, methionine, methionine plus cysteine, and / or lysine is within any one of ranges 2, 3, 4 or 5 in Table B of WO 01 / 58275 (R. 2-5).

[0405] Crude protein is calculated as nitrogen (N) multiplied by a factor 6.25, i.e. Crude protein (g / kg)= N (g / kg) x 6.25. The nitrogen content is determined by the Kjeldahl method (A.O.A.C., 1984, Official Methods of Analysis 14th ed., Association of Official Analytical Chemists, Washington DC).

[0406] Metabolisable energy can be calculated on the basis of the NRC publication Nutrient requirements in swine, ninth revised edition 1988, subcommittee on swine nutrition, committee on animal nutrition, board of agriculture, national research council. National Academy Press, Washington, D.C., pp. 2-6, and the European Table of Energy Values for Poultry Feed-stuffs, Spelderholt centre for poultry research and extension, 7361 DA Beekbergen, The Netherlands. Grafisch bedrijf Ponsen & looijen bv, Wageningen. ISBN 90-71463-12-5.

[0407] The dietary content of calcium, available phosphorus and amino acids in complete animal diets is calculated on the basis of feed tables such as Veevoedertabel 1997, gegevens over chemische samenstelling, verteerbaarheid en voederwaarde van voedermiddelen, Central Veevoederbureau, Runderweg 6, 8219 pk Lelystad. ISBN 90-72839-13-7.

[0408] In a particular embodiment, the animal feed composition of the invention contains at least one vegetable protein as defined above.

[0409] The animal feed composition of the invention may also contain animal protein, such as Meat and Bone Meal, Feather meal, and / or Fish Meal, typically in an amount of 0-25%. The animal feed composition of the invention may also comprise Dried Distillers Grains with Solubles (DDGS), typically in amounts of 0-30%.

[0410] In still further particular embodiments, the animal feed composition of the invention contains 0-80% maize; and / or 0-80% sorghum; and / or 0-70% wheat; and / or 0-70% Barley; and / or 0-30% oats; and / or 0-40% soybean meal; and / or 0-25% fish meal; and / or 0-25% meat and bone meal; and / or 0-20% whey.

[0411] The animal feed may comprise vegetable proteins. In particular embodiments, the protein content of the vegetable proteins is at least 10, 20, 30, 40, 50, 60, 70, 80, or 90% (w / w). Vegetable proteins may be derived from vegetable protein sources, such as legumes and cereals, for example, materials from plants of the families Fabaceae (Leguminosae), Cruciferaceae, Chenopodiaceae, and Poaceae, such as soy bean meal, lupin meal, rapeseed meal, and combinations thereof.

[0412] In a particular embodiment, the vegetable protein source is material from one or more plants of the family Fabaceae, e.g., soybean, lupine, pea, or bean. In another particular embodiment, the vegetable protein source is material from one or more plants of the family Chenopodiaceae, e.g. beet, sugar beet, spinach or quinoa. Other examples of vegetable protein sources are rapeseed, and cabbage. In another particular embodiment, soybean is a preferred vegetable protein source. Other examples of vegetable protein sources are cereals such as barley, wheat, rye, oat, maize (corn), rice, and sorghum.

[0413] Animal diets can e.g. be manufactured as mash feed (non-pelleted) or pelleted feed. An aspect of the invention is directed to pelleted animal feed prepared using the method of the invention or by pelleting the animal feed of the invention. Typically, the milled feed-stuffs are mixed and sufficient amounts of essential vitamins and minerals are added according to the specifications for the species in question. Enzymes can be added as solid or liquid enzyme formulations. For example, for mash feed a solid or liquid enzyme formulation may be added before or during the ingredient mixing step. For pelleted feed the (liquid or solid) xylanase / enzyme preparation may also be added before or during the feed ingredient step. Typically a liquid xylanase / enzyme preparation comprises the xylanase of the invention optionally with a polyol, such as glycerol, ethylene glycol or propylene glycol, and is added after the pelleting step, such as by spraying the liquid formulation onto the pellets. The enzyme may also be incorporated in a feed additive or premix.

[0414] Alternatively, the xylanase can be prepared by freezing a mixture of liquid enzyme solution with a bulking agent such as ground soybean meal, and then lyophilizing the mixture.

[0415] The final enzyme concentration in the diet is within the range of 0.01-200 mg enzyme protein per kg diet, preferably between 0.05-100 mg / kg diet, more preferably 0.1-50 mg, even more preferably 0.2-20 mg enzyme protein per kg animal diet.

[0416] It is at present contemplated that the enzyme is administered in one or more of the following amounts (dosage ranges): 0.01-200; 0.05-100; 0.1-50; 0.2-20; 0.1-1; 0.2-2; 0.5-5; or 1-10; - all these ranges being in mg xylanase protein per kg feed (ppm).

[0417] For determining mg xylanase protein per kg feed, the xylanase is purified from the feed composition, and the specific activity of the purified xylanase is determined using a relevant assay (see under xylanase activity). The xylanase activity of the feed composition as such is also determined using the same assay, and on the basis of these two determinations, the dosage in mg xylanase protein per kg feed is calculated.

[0418] In a particular embodiment, the animal feed additive of the invention is intended for being included (or prescribed as having to be included) in animal diets or feed at levels of 0.01 to 10.0%; more particularly 0.05 to 5.0%; or 0.2 to 1.0% (% meaning g additive per 100 g feed). This is so in particular for premixes.

[0419] The same principles apply for determining mg xylanase protein in feed additives. Of course, if a sample is available of the xylanase used for preparing the feed additive or the feed, the specific activity is determined from this sample (no need to purify the xylanase from the feed composition or the additive).Plant based material from the sub-family Panicoideae

[0420] In one embodiment, the plant based material from the sub-family Panicoideae is from the tribe Andropogoneae such as the rank Andropogon or Andropterum or Apluda or Apocopis or Arthraxon or Bothriochloa or Capillipedium or Chionachne or Chrysopogon or Coelorachis or Coix or Cymbopogon or Dichanthium or Diheteropogon or Dimeria or Elionurus or Eremochloa or Euclasta or Eulalia or Germainia or Hemarthria or Heteropholis or Heteropogon or Hyparrhenia or Hyperthelia or Imperata or Ischaemum or Iseilema or Kerriochloa or Microstegium or Miscanthidium or Miscanthus or Mnesithea or Ophiuros or Oxyrhachis or Phacelurus or Pholiurus or Pogonatherum or Polytoca or Polytrias or Pseudopogonatherum or Pseudosorghum or Rhytachne or Rottboellia or Saccharum (e.g. sugar cane) or Sarga or Schizachyrium or Sehima or Sorghastrum or Sorghum or Spodiopogon or Thaumastochloa or Thelepogon or Themeda or Trachypogon or Triarrhena or Tripsacum or Urelytrum or Vetiveria or Vossia or Xerochloa or Zea.

[0421] In a preferred embodiment, the plant based material from the sub-family Panicoideae is from the rank Zea, such as the species Zea diploperennis, Zea luxurians, Zea mays, Zea nicaraguensis or Zea perennis.

[0422] In a preferred embodiment, the plant based material from the sub-family Panicoideae is from the rank Sorghum, such as the species Sorghum amplum, Sorghum angustum, Sorghum arundinaceum, Sorghum australiense, Sorghum bicolor, Sorghum brachypodum, Sorghum bulbosum, Sorghum ecarinatum, Sorghum exstans, Sorghum grande, Sorghum halepense, Sorghum hybrid cultivar, Sorghum interjectum, Sorghum intrans, Sorghum laxiflorum, Sorghum leiocladum, Sorghum macrospermum, Sorghum matarankense, Sorghum nitidum, Sorghum plumosum, Sorghum propinquum, Sorghum purpureosericeum, Sorghum stipoideum, Sorghum sudanense, Sorghum timorense, Sorghum versicolor, Sorghum sp. 'Silk' or Sorghum sp. as defined in WO2007 / 002267.

[0423] In another embodiment, the plant based material from the sub-family Panicoideae is from the tribe Paniceae such as the rank Acritochaete, Acroceras, Alexfloydia, Alloteropsis, Amphicarpum, Ancistrachne, Anthephora, Brachiaria (e.g. signal grass), Calyptochloa, Cenchrus, Chaetium, Chaetopoa, Chamaeraphis, Chlorocalymma, Cleistochloa, Cyphochlaena, Cyrtococcum, Dichanthelium, Digitaria, Dissochondrus, Echinochloa, Entolasia, Eriochloa, Homopholis, Hygrochloa, Hylebates, Ixophorus, Lasiacis, Leucophrys, Louisiella, Megal...

Claims

1. A xylanase variant having xylanase activity, wherein the variant has at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 1 and comprises a substitution at a position corresponding to position 2 of SEQ ID NO: 1, selected from the group consisting of A2D, A2Q, A2G, A2W and A2P, and wherein the position corresponds to the position of SEQ ID NO: 1, wherein the variant has improved thermostability compared to the SEQ ID NO: 1.

2. A composition comprising the xylanase variant defined in claim 1 and a formulating agent.

3. A granule comprising the xylanase variant defined in claim 1 and a formulating agent, wherein the granule comprises a core particle and one or more coatings.

4. An animal feed additive comprising the xylanase variant defined in claim 1, the composition of claim 2 or the granule of claim 3 and one or more components selected from the group consisting of: one or more vitamins; one or more minerals; one or more amino acids; one or more phytogenics; one or more prebiotics; one or more organic acids; and one or more other ingredients.

5. A liquid formulation comprising the xylanase variant defined in claim 1 , wherein the xylanase variant is dosed between 0.01% to 25% w / w of liquid formulation, preferably 0.05% to 20% w / w, more preferably 0.2% to 15% w / w, more preferably 0.5% to 15% w / w or most preferably 1.0% to 10% w / w xylanase variant.

6. An animal feed comprising the xylanase variant defined in claim 1, the composition of claim 3, the granule of claim 4, the animal feed additive of claim 5 or the liquid formulation of claim 6 and plant based material.

7. Use of the xylanase variant defined in claim 1, the composition of claim 2, the granule of claim 3, the animal feed additive of claim 4or the liquid formulation of claim 5 or the animal feed of claim 6: in animal feed; in animal feed additives; in the preparation of a composition for use in animal feed; for improving the nutritional value of an animal feed; for increasing digestibility of an animal feed; for improving one or more performance parameters in an animal; for solubilizing xylan from plant based material for releasing starch from plant based material.

8. A process of producing a fermentation product, comprising the following steps: (a) saccharifying a starch-containing material at a temperature below the initial gelatinization temperature with an alpha-amylase, a glucoamylase, and a xylanase variant defined in claim 1; and (b) fermenting using a fermentation organism.

9. A method for preparing a dough or a baked product prepared from the dough which method comprises incorporating into the dough a xylanase variant defined in claim 1.

10. A polynucleotide encoding the xylanase variant as defined in claim 1.

11. A recombinant host cell comprising the polynucleotide of claim 10 operably linked to one or more control sequences that direct the production of the polypeptide.

12. A method of producing the xylanase variant defined in claim 1, comprising: (a) cultivating the recombinant host cell of claim 11 under conditions conducive for production of the polypeptide; and (b) recovering the polypeptide.

13. The xylanase variant according to claim 1, having one or more substitutions, wherein the number of substitutions is 1-35, e.g., 1-30, 1-25, 1-20, 1-15, 1-10 or 1-5 substitutions.

14. The xylanase variant according to claim 1, having one or more substitutions, wherein the number of substitutions is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38 or 39 substitutions.