58 results about "Xylosidases" patented technology

Isolated and / or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius and variations thereof are provided. Further provided are methods of at least partially degrading xylotriose, xylobiose, and / or arabinofuranose-substituted xylan using isolated and / or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius and variations thereof.

Xylose-containing plant material may be hydrolyzed to xylose using a β-D-xylosidase which exhibits unexpectedly high activity. The enzyme has a kcat value for catalysis of approximately 185 sec−1 for 1,4-β-D-xylobiose (X2) when measured at a pH of 5.3 and a temperature of 25° C.; this is at least 10-fold greater than reported for other xylosidases at 25° C. and their optimal pH. The enzyme also has an isoelectric point of approximately 4.4. When reacted at a pH between about 4.5 and about 7.7, the β-D-xylosidase exhibits surprisingly high activity for hydrolyzing xylose-containing plant materials to xylose. The xylose released from plant materials may then be converted to other secondary products such as ethanol by fermentation or other reaction. This β-D-xylosidase may be used alone or in combination with other hydrolytic or xylanolytic enzymes for treatment of lignocellulosic or hemicellulosic plant materials or plant material hydrolysates or xylooligosaccharides.

The invention discloses a method for producing xylanase at high yield from trichoderma reesei and application of the xylanase, and belongs to the technical field of bioengineering. According to the invention, a transcription activator XYR1 is expressed to enhance the xylan degrading enzyme expression ability, and a transcription factor binding site on a promoter Pcbh1 is designed, so that XYR1 of constitutive expression can further activate the artificial promoter Pcbh1, and the artificial promoter Pcbh1 is used for expressing homologous xylanase XYNII to obtain recombinant trichoderma reesei. Under the cellulose induction condition, the expression quantity of the recombinant strain xylanase reaches 6410U / mL, which is 9.28 times higher than that of a parent; meanwhile, the activity of xylosidase is improved by 1.93 times and reaches 9.08 U / mL; and the recombinant strain can relieve carbon metabolism repression, soluble cheap carbon sources glucose and lactose are used as fermentation carbon sources, the activity of the extracellular xylanase of 2514 U / mL and the activity of the extracellular xylanase of 3446 U / mL can also be obtained, and meanwhile, the yield of the xylosidase is increased by 9.3 times and 2.3 times compared with that of the parent. Meanwhile, the xylanase produced with the method cooperates with commercial cellulose to perform straw saccharification, so that the saccharification efficiency can be improved by 35%.

The invention provides polypeptides having any cellulolytic activity, e.g., a cellulase activity, a endoglucanase, a cellobiohydrolase, a beta-glucosidase, a xylanase, a mannanse, a beta-xylosidase, an arabinofiiranosidase, and / or an oligomerase activity, polynucleotides encoding these polypeptides, and methods of making and using these polynucleotides and polypeptides. In one aspect, the invention is directed to polypeptides having any cellulolytic activity, e.g., a cellulase activity, e.g., endoglucanase, cellobiohydrolase, beta-glucosidase, xylanase, mannanse, beta-xylosidase, arabinofuranosidase, and / or oligomerase activity, including thermostable and thermotolerant activity, and polynucleotides encoding these enzymes, and making and using these polynucleotides and polypeptides. In one aspect, the invention provides polypeptides having an oligomerase activity, e.g., enzymes that convert recalcitrant soluble oligomers to fermentable sugars in the saccharification of biomass. The polypeptides of the invention can be used in a variety of pharmaceutical, agricultural, food and feed processing and industrial contexts. The invention also provides compositions or products of manufacture comprising mixtures of enzymes comprising at least one enzyme of this invention.

Xylose-containing plant material may be hydrolyzed to xylose using a β-D-xylosidase which exhibits unexpectedly high activity. The enzyme has a kcat value for catalysis of approximately 185 sec−1 for 1,4-β-D-xylobiose (X2) when measured at a pH of 5.3 and a temperature of 25° C.; this is at least 10-fold greater than reported for other xylosidases at 25° C. and their optimal pH. The enzyme also has an isoelectric point of approximately 4.4. When reacted at a pH between about 4.5 and about 7.7, the β-D-xylosidase exhibits surprisingly high activity for hydrolyzing xylose-containing plant materials to xylose. The xylose released from plant materials may then be converted to other secondary products such as ethanol by fermentation or other reaction. This β-D-xylosidase may be used alone or in combination with other hydrolytic or xylanolytic enzymes for treatment of lignocellulosic or hemicellulosic plant materials or plant material hydrolysates or xylooligosaccharides.

The invention belongs to the technical field of catalysis, and provides a method for preparing cycloastragenol by catalyzing astragaloside through co-immobilized double enzymes. The method comprises the following steps of: carrying out a reaction among beta-glucosidase, a phosphate buffer solution, a Fe3O4 solution, a copper chloride solution and xylosidase to obtain the co-immobilized double enzymes; and carrying out a catalytic reaction by using co-immobilized double enzymes and astragaloside to obtain cycloastragenol. The method provided by the invention overcomes the problem of extractionand separation of intermediates in a process for preparing cycloastragenol by adopting a two-step reaction in the prior art, and meanwhile, the co-immobilized double enzymes can be recycled, so that the production cost is reduced, the process is simple, economic and economical, and the method is very suitable for large-scale industrial production. The conversion rate of the co-immobilized double enzymes to astragaloside basically reaches 100%, and the substrate astragaloside is completely converted into cycloastragenol. The purity of the cycloastragenol product obtained by the method can reach78.3% or above.

A process for extracting phytochemicals from plants. The process generally comprises controllably slurrying a selected plant material in a volume, adding a selected enzyme the slurry while it is controllably agitated, then heating the controllably agitated slurry-enzyme mixture to a temperature from the range of 40° C. to 110° C., and then maintaining the slurry-enzyme mixture at that temperature for a selected period of time. The slurry is then separated into a solids fraction and a liquids fraction that contains extracted phytochemicals. The liquids fraction is controllably de-watered to produce a fluid extract concentrate. The liquids fraction may optionally be dried to produce a dried extract concentrate. Suitable enzymes for use with this process include α-amylases, β-amylases, endo-β-1,4-glucanases, cellobiohydrolases, cellulases, hemicellulases, β-glucosidases, β-xylosidases, xylanases, pullulases, esterases and mixtures thereof.

The invention discloses a salt-tolerant xylosidase mutant T329E and its preparation method and application. The amino acid sequence of the mutant T329E is obtained by mutating the threonine at position 329 of wild xylosidase HJ14GH43 into glutamic acid. Its sequence is shown in SEQ ID NO.1, and the salt is not NaCl. Compared with the wild enzyme HJ14GH43, the mutant enzyme T329E of the present invention has a high concentration of KCl, Na 2 SO 4 and (NH 4 ) 2 SO 4 The stability in the medium has been enhanced, after 15.0-30.0% concentration of KCl treatment, its activity remains 59-70%; after 15.0-30.0% concentration of Na 2 SO 4 After treatment, its activity remained 78-87%; after 20.0-30.0% concentration (NH 4 ) 2 SO 4 After treatment, its activity is increased by about 20%, which can be applied to industries such as tanning, papermaking, and sewage treatment.

The invention belongs to the field of biological engineering and provides a novel bifunctional enzyme RuXyn1 with low-temperature resistance and activities of beta-D-xylosidase and alpha-L-arabinofuranosidase. The RuXyn1 has an amino acid coding sequence shown as SEQ ID No 2 and has a nucleotide coding sequence shown as SEQ ID No 1. The RuXyn1 can be prepared by a genetic engineering method or anartificial synthesis method. The RuXyn1 has functions of the arabinofuranosidase and the xylosidase, can keep higher activity in a low-temperature environment, and can be applied to the application fields of cellulose bioconversion, chemical industry, textiles, foods, bioenergy, feed additives, pharmaceutical industry and the like.

The invention relates to the technical field of genetic engineering and protein transformation, and discloses a sodium chloride- and potassium chloride-resistant xylosidase mutant H328D and its application. The amino acid sequence of the mutant H328D is shown in SEQ ID NO.1. The mutant has good stability in high concentrations of NaCl and KCl. After being treated with 3.0-30.0% (w / v) NaCl for 60 minutes, the activity is 44-60%; After 60 minutes of treatment, the activity was 73-105%. The sodium chloride and potassium chloride resistant xylosidase mutant H328D of the present invention can be applied to industries such as food, agriculture, and sewage treatment.

The invention discloses salt-tolerant xylosidase mutant K321D as well as a preparation method and application thereof. The amino acid sequence of the mutant K321D is obtained by mutating lysine at the321st site of wild xylosidase HJ14GH43 into aspartic acid, the sequence of the mutant K321D is shown as SEQ ID NO.1, and the salt is not NaCl. Compared with wild enzyme HJ14GH43, the mutant has the advantages that the stability of the mutant enzyme K321D disclosed by the invention in high-concentration KCl, Na2SO4 and (NH4) 2SO4 is enhanced; the activity increased from 48% to 65% after being treated with KCl with the concentration of 20.0%-30.0%, and the activity is 93%-111% after being treated with Na2SO4 with the concentration of 10.0%-30.0%; and the activity is maintained to be higher than90% after being treated with (NH4) 2SO4 with the concentration of 20.0-30.0%; and the salt-tolerant xylosidase mutant K321D can be applied to industries such as tanning, papermaking, sewage treatmentand the like.