Xylanase variants and methods

Abstract

The present disclosure provides variant xylanase enzymes for use in biobleaching and biodeinking process of the paper and pulp industry.

Description

[0001]A y Docket No. 114095-5014-WOXYLANASE VARIANTS AND METHODS FIELD OF THE INVENTIONThis disclosure relates to the variant xylanase enzymes, polynucleo des encoding the variantxylanase enzymes, methods of producing the variant xylanase enzymes, and methods of using the variant xylanase enzymes. Also described are the use of variant xylanases in the paper and pulpindustry as a biobleaching agent. The disclosure also relates to composi ons comprising one or morevariant xylanases. BACKGROUND OF THE INVENTION Xylan is a complex heteropolysaccharide comprised of various monosaccharides, including L-arabinose, D-galactose, D-mannose, and organic acids such as ace c acid, ferulic acid, and glucuronicacid, interconnected through glycosidic and ester bonds. Its heterogeneous nature presentschallenges for breakdown, which can be e ec vely addressed by xylanases. These enzymes have thecapability to cleave the -1,4-glycosidic linkages in xylan, facilita ng its decomposi on. Xylanases arewidely distributed in nature, found in organisms ranging from mollusks and insects to a diverse arrayof microorganisms—bacteria, fungi, ac nomycetes, yeast and archaea.Xylanase have found applica ons in various industry processes. In the paper and pulp industry,xylanases, especially those that are thermostable and alkaline stable, have proven to be invaluable in biobleaching processes. These enzymes disrupt the xylan-lignin bond within pulp bers, therebyfacilita ng the removal of lignin, enhancing pulp brightness, and reducing the dependency ontradi onal chemical bleaching agents, such as chlorine and hydrogen peroxide. The use of xylanasesin this context not only mi gates the environmental footprint of chemical bleaching but alsosupports a more sustainable pulp processing technique by minimizing damage to the pulp bers.In addi on to their demonstrated e cacy in biobleaching, xylanases have also shown promise in thebiodeinking of waste paper, par cularly when used in combina on with laccase. The enzyma cprocess, by modifying the structure of xylan within paper bers, could enhance ink removal, therebyimproving both the e ciency and environmental sustainability of paper recycling processes.A y Docket No. 114095-5014-WOThe present disclosure aims to introduce variant xylanases with enhanced enzyme ac vity at hightemperature and alkaline condi ons. This superior performance may result from improvements inspeci c ac vity, protein produc on, thermal ac vity, thermal stability, alkaline ac vity and / oralkaline stability of these variants. Moreover, selected variants demonstrate an enhanced paperbleaching e ect in industry-relevant applica ons. The disclosure encompasses polynucleo desencoding these xylanase variants. Overall, the present disclosure promises signi cant advancementsin enhancing e ciency and reducing the environmental impact of biobleaching and poten allybiodeinking processes, by harnessing the unique proper es of these engineered enzymes.BRIEF SUMMARY OF THE INVENTION Accordingly, the present disclosure provides (variant) xylanases and methods of producing and using them. The amino acid sequence numbers and nucleic acid sequence numbers of the present disclosure are listed in Table 1. Table 1. Amino acid sequence numbers and nucleic acid sequence numbers. In one aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1, wherein said aminoacid subs tu on is at a posi on number selected from the group consis ng of 322, 1, 29, 67, 70, 215,2, 3, 4, 5, 8, 22, 24, 32, 33, 50, 54, 55, 56, 57, 66, 69, 77, 91, 92, 93, 99, 104, 109, 112, 116, 127, 137, 144, 164, 178, 179, 184, 188, 193, 199, 203, 204, 206, 213, 218, 241, 247, 251, 252, 256, 263, 264,A y Docket No. 114095-5014-WO266, 267, 270, 271, 272, 292, 293, 295, 297, 317, 318, 321, 323, 325, 327 and 328, and wherein saidvariant enzyme is at least 90% iden cal to SEQ ID NO:1.In a further aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising an amino acid subs tu on at posi on 322 and at least one further amino acidsubs tu on as compared to SEQ ID NO:1, wherein said amino acid subs tu on is at a posi onnumber selected from the group consis ng of 1, 29, 67, 70, 215, 2, 3, 4, 5, 8, 22, 24, 32, 33, 50, 54,55, 56, 57, 66, 69, 77, 91, 92, 93, 99, 104, 109, 112, 116, 127, 137, 144, 164, 178, 179, 184, 188, 193, 199, 203, 204, 206, 213, 218, 241, 247, 251, 252, 256, 263, 264, 266, 267, 270, 271, 272, 292, 293, 295, 297, 317, 318, 321, 323, 325, 327 and 328, and wherein said variant xylanase enzyme is at least90% iden cal to SEQ ID NO:1.In an addi onal aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1, wherein said aminoacid subs tu on is at a posi on number selected from the group consis ng of 322, 1, 29, 67, 70, 215,2, 3, 4, 5, 8, 22, 24, 32, 33, 50, 54, 55, 56, 57, 66, 69, 77, 91, 92, 93, 99, 104, 109, 112, 116, 127, 137, 144, 164, 178, 179, 184, 188, 193, 199, 203, 204, 206, 213, 218, 241, 247, 251, 252, 256, 263, 264, 266, 267, 270, 271, 272, 292, 293, 295, 297, 317, 318, 321, 323, 325, 327 and 328, wherein saidvariant xylanase enzyme has at least 1.1 fold be er ac vity as compared to SEQ ID NO:1 under acondi on selected from the group consis ng of tolerance against pH 7.5, tolerance against pH 8,tolerance against pH 8.5, tolerance against pH 9, tolerance against pH 9.5, tolerance against pH 10, tolerance against pH 10.5, tolerance against pH 11, tolerance against pH 11.5, tolerance against pH 12, tolerance against pH 12.5, tolerance against pH 13, tolerance against pH 13.5 and toleranceagainst pH 14; and wherein said variant xylanase enzyme is at least 90% iden cal to SEQ ID NO:1.In a further aspect, the disclosure provides a composi on comprising a variant xylanase enzymeexhibi ng at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% iden ty to SEQ ID NO:1.In an addi onal aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1 as described herein,wherein said amino acid subs tu on(s) occur at one of said posi ons, two of said posi ons, three ofsaid posi ons, four of said posi ons, ve of said posi ons, six of said posi ons, seven of saidposi ons, eight of said posi ons, nine of said posi ons, ten of said posi ons, eleven of said posi ons,twelve of said posi ons, thirteen or more of said posi ons.A y Docket No. 114095-5014-WOIn a further aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1 as described herein,wherein said amino acid subs tu on(s) is selected from the group consis ng of K322D, K322E,K322F, K322G, K322L, K322S, K322T, K322V, K322W, S1Y, S29D, S29Y, P67T, K70P, K70H, K70L, K70R, R215N, R215D, R215L, R215M, R215S, R215T, R215V, Q2P, Q2S, Q2Y, N3T, V4E, V4N, S5Q, S5Y, E8G, I22D, I22E, I22Q, I22T, N24D, N24H, N24Q, N24S, E32D, K33E, K33F, K33M, K33R, Q50A, Q50D, Q50E, Q50G, Q50N, Q50S, Q50Y, D54E, D54G, D54H, D54Y, T55A, T55D, T55K, T55L, T55N, T55P, T55R, T55S, T55V, I56T, I56V, H57E, T66A, T66P, T66R, T66V, E69D, E77R, N91Q, N91S, N91T, Q92L, Q92S, Q92W, L93N, G99D, G99R, K104R, N109E, N109F, N109T, N109W, E112A, E112C, E112D, E112F, E112G, E112I, E112K, E112L, E112N, E112P, E112R, E112S, E112T, E112V, E112W, E112Y, K116C, K116G, K116S, K127L, K127T, S137N, E144S, E144Y, K164H, S178G, S178N, I179A, I179L, I179M, I179T, I179V, A184C, A184F, A184H, A184N, A184Q, A184S, A184T, A184W, A184Y, F188A, I193T, K199R, V203I, D204H, I206V, D213T, N218K, N218Q, N218T, N218W, M241L, M241T, M241V, L247A, L247E, L247T, E251C, E251L, E251N, E251V, E252L, K256E, K256P, A263R, K264R, F266A, F266E, F266G, F266I, F266K, F266L, F266P, F266Q, F266S, F266T, F266V, F266Y, D267A, D267F, D267I, D267K, D267L, D267M, D267T, D267W, L270W, D271R, D271Y, N272H, N272P, N272T, G292A, G292D, G292E, G292N, G292S, F293T, F293V, F293W, F293Y, K295E, K295I, K295L, K295N, K295S, Y297A, Y297E, Y297Q, Y297T, K317E, K317G, K317M, K317N, K317T, K317W, E318I, E318L, E318N, E318P, E321G, K323A, K323C, K323D, K323E, K323F, K323G, K323I, K323L, K323S, K323T, K323V, E325V, R327A, R327C, R327E, R327F, R327G, R327H, R327I, R327L, R327N, R327S, R327T, R327V, R327Y, K328N and K328P.In an addi onal aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1 as described herein,wherein said amino acid subs tu on(s) is selected from the group consis ng of K322D,K322D / S1Y / S29D / P67T / K70P, K322D / S1Y / S29D / P67T / K70P / R215N, K164H, V203I / I206V / A263R, K199R / V203I / I206V / A263R, A263R, I206V / A263R, E69D / K164H / K199R / D204H, K104R / F188A / I206V, E69D / V203I / D204H / A263R, E69D / K164H / V203I / I206V, E69D / K164H / A263R, K164H / F188A / I206V, V203I, K164H / K199R / I206V / A263R, V203I / I206V, E69D / K164H / I206V, D204H / I206V / A263R, F188A / V203I / A263R, K164H / F188A / K199R / V203I, K104R / K164H, E69D / K164H / K199R / V203I / I206V / A263R, E8G, Q2S, K33R, P67T, K33E, E32D, G99D, K70R, K116S, N109W, V4E, V4N, N109T, S1Y, N3T, K70H, S5Q, Q2Y, K127T, K33M, K116G, N109E, N109F, G99R, K70L, S29D, K33F, K116C, K323L, D267I, E251N, K317M, E325V, D271Y, E318N, K323V, E252L, E318I, D267T, L247T, E251C / K323T, K295N, K322W, K317T, D271R, E251V, K295L, K295S, D267M, K323F, K256P, E321G, N272P, K322F, D267A, K322L, L247A, K328N, K323D, D267F, K323I, K295I, K323S,A y Docket No. 114095-5014-WOD267L, K323A, N272T, E318L, K323T, K322E, K317G, K323E, D267W, K256E, D267K, K322S, K317W, K322V, K323G, K322T, E251L, K317E, N272H / K328P, L247E, K323C, K317N, K322G, E318P, E32D / K33E, N3T / K70P / E251N / K295N, L247A / E251N, Q2P / E32D / L247A, E32D / E251N / D267I, K70P, E32D / K33E / K70P / L247A, Q2P / N3T / D267I, E251N / D267I, N3T / E32D / K33E / D267I / K295N / K322D, Q2P, Q2P / K70P, Q2P / N3T, E32D / K33E / E251N, E32D / L247A, Q2P / N3T / K70P, Q2P / N3T / E32D / L247A / K295I, Q2P / K70P / E251N, N3T / K33E / E251N, N3T / E32D, K33E / L247A, L247A / D267I / K295I / K322D, Q2P / K295N, N3T / K127L / D267I / K295N, E251N / K322D / K323S, K70P / E251N / D267I / K295N, N3T / E32D / K33E / K70P / K127L / D267I, K33E / K70P / D267I, N3T / E32D / L247A / D267I, K33E / K70P, Q2P / E251N / D267I / K322D, E32D / K70P / K127L / D267I, K33E / K70P / E251N / K295L / K322D, N3T / K33E / K70P / K295I / K323S, K33E / K127L / K295N, Q2P / K33E / K70P / K295I, Q2P / E32D / K70P / K322D / K323S, N3T / K70P / L247A / E251N, E32D / K33E / K295N / K322D, K70P / D213T / D267I, Q2P / K70P / D267I, K322D / F266A, R327H, K322D / Q50N, K322D / E112N, K322D / I22E, K322D / E112P, R327C, K322D / R327T, K322D / N218T, K322D / E144Y, K322D / E112S, K322D / M241T, K322D / N218Q / F266K, K322D / E112D, K322D / R327N, K322D / E112K, K322D / E112F, K322D / F266P, K322D / E112I, K322D / R327I, K322D / A184W, K322D / E112C, K322D / E112Y, R327V, K322D / T66A, K322D / A184T, K322D / E112T, K322D / Q50Y, K322D / E112W, K322D / E112R, K322D / N218W, K322D / A184C, K322D / E112G, R327G, K322D / N218K, K322D / K264R / F266P, K322D / I22T, R327F, R327Y, K322D / F266V, K322D / A184S, K322D / A184W / I193T, K322D / Q50G, K322D / T66R, K322D / Q92S, K322D / F266Q, R327S, K322D / F266Q / L270W, K322D / I179M / M241L, R327T, R327E, K322D / A184N, K322D / F266Y, K322D / E144S, K322D / T66V, K322D / E112L, K322D / A184H, K322D / A184Y, K322D / I22D, K322D / E112V, K322D / F266E, K322D / F266S, K322D / F266T, K322D / F266I, K322D / E112A, K322D / Q92W, K322D / Q92L, K322D / I22Q, K322D / T66P, K322D / F266G, K322D / F266L, K322D / M241V, R327L, R327A, K322D / A184F, K322D / Q50G / A184Q / G292E, K322D / Q92S / G292A, K322D / I22E / F266V, K322D / I22T / E112R / F266L, K322D / Q2Y / N3T / E32D / K33R / E77R / K256E, K322D / S29D / N109E / E251V, K322D / K33E / K116S / K317E, K322D / S29D / D267A / E318N, K322D / N3T / E8G / K256E, K322D / Q2S / N3T / E8G / E32D / K116S / D271R, K322D / V4N / S5Q / S29D / K295N, K322D / P67T / K70L / K127L / D267A, K322D / S29D / N109T / K127L / K295N, K322D / V4E / S5Q / S29D / K295N / E318L, K322D / S1Y / S29D / P67T / K70P / I56V / H57E / N91Q / L93N, K322D / S1Y / S29D / P67T / K70P / N24H / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / T55A / N91Q / R215N, K322D / S1Y / S29D / P67T / K70P / T55V, K322D / S1Y / S29D / P67T / K70P / D54Y / T55N / S178G / I179A / K295E / Y297Q / K317T, K322D / S1Y / S29D / P67T / K70P / Q50A / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / I56V / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / N24D / Q50G / K295E, K322D / S1Y / S29D / P67T / K70P / I56T / K295E, K322D / S1Y / S29D / P67T / K70P / D54Y / T55N / F293T,A y Docket No. 114095-5014-WOK322D / S1Y / S29D / P67T / K70P / N24H / Q50E / S137N / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / K295E, K322D / S1Y / S29D / P67T / K70P / N91Q / R215N / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / D54E / T55V / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / D54Y / T55V, K322D / S1Y / S29D / P67T / K70P / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / N24D / D54Y / T55S / G292D / F293Y / K317T, K322D / S1Y / S29D / P67T / K70P / Q50D / R215N / F293Y, K322D / S1Y / S29D / P67T / K70P / T55V / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / K317T, K322D / S1Y / S29D / P67T / K70P / D54Y / T55N / N91S / I179L / K295E, K322D / S1Y / S29D / P67T / K70P / N24H / N91Q, K322D / S1Y / S29D / P67T / K70P / N24D / D54E / T55A / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / N24D / D54Y / T55S / S178N / I179V / K295E / K317T, K322D / S1Y / S29D / P67T / K70P / I56T / L93N / G292S / F293W, K322D / S1Y / S29D / P67T / K70P / Q50G / K295E / Y297Q / K317T, K322D / S1Y / S29D / P67T / K70P / Q50S / K295E, K322D / S1Y / S29D / P67T / K70P / I56T / H57E / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / I56V / H57E / F293T, K322D / S1Y / S29D / P67T / K70P / T55S / S137N, K322D / S1Y / S29D / P67T / K70P / T55N, K322D / S1Y / S29D / P67T / K70P / D54Y / T55V / N91S / K295E / K317T, K322D / S1Y / S29D / P67T / K70P / D54E / T55R / N91Q / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / N24D / D54Y / G292N / F293W, K322D / S1Y / S29D / P67T / K70P / N24D / N91S / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / I56V, K322D / S1Y / S29D / P67T / K70P / D54G / T55P / R215N / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / N24D / D54Y / R215N / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / N24D / N91Q / L93N / G292A / F293Y, K322D / S1Y / S29D / P67T / K70P / N24D / T55N / N91Q / S137N / S178G / I179T / R215N / K317T, K322D / S1Y / S29D / P67T / K70P / N24D / I56V / G292D / F293Y, K322D / S1Y / S29D / P67T / K70P / I56V / H57E / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / N24D, K322D / S1Y / S29D / P67T / K70P / T55V / L93N, K322D / S1Y / S29D / P67T / K70P / Q50G / R215N, K322D / S1Y / S29D / P67T / K70P / N24D / I56V / I179V / R215N, K322D / S1Y / S29D / P67T / K70P / N24H, K322D / S1Y / S29D / P67T / K70P / N24D / Q50G / G292S / F293V, K322D / S1Y / S29D / P67T / K70P / G292S, K322D / S1Y / S29Y / P67T / K70P / N24D / I56T / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / T55V / K295E, K322D / S1Y / S29D / P67T / K70P / N24H / Q50A / K295E, K322D / S1Y / S29D / P67T / K70P / D54E / T55V / N91S / K295E, K322D / S1Y / S29D / P67T / K70P / T55N / G292S / F293T, K322D / S1Y / S29D / P67T / K70P / I56T / H57E / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / I56T / H57E, K322D / S1Y / S29D / P67T / K70P / N24D / I56T / H57E,A y Docket No. 114095-5014-WOK322D / S1Y / S29D / P67T / K70P / N24H / D54Y / T55A / N91S / L93N / S137N / K295E, K322D / S1Y / S29D / P67T / K70P / D54Y / T55A / R215N / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / T55K, K322D / S1Y / S29D / P67T / K70P / N91T, K322D / S1Y / S29D / P67T / K70P / D54H, K322D / S1Y / S29D / P67T / K70P / R215M, K322D / S1Y / S29D / P67T / K70P / T55R, K322D / S1Y / S29D / P67T / K70P / R215D, K322D / S1Y / S29D / P67T / K70P / T55P, K322D / S1Y / S29D / P67T / K70P / Y297A, K322D / S1Y / S29D / P67T / K70P / N24Q, K322D / S1Y / S29D / P67T / K70P / N24S, K322D / S1Y / S29D / P67T / K70P / R215V, K322D / S1Y / S29D / P67T / K70P / R215S, K322D / S1Y / S29D / P67T / K70P / Y297T, K322D / S1Y / S29D / P67T / K70P / T55D, K322D / S1Y / S29D / P67T / K70P / T55L, K322D / S1Y / S29D / P67T / K70P / R215L, K322D / S1Y / S29D / P67T / K70P / R215T, K322D / S1Y / S29D / P67T / K70P / N91Q, K322D / S1Y / S29D / P67T / K70P / F293T / K295N, K322D / S1Y / S29D / P67T / K70P / E32D, K322D / S1Y / S29D / P67T / K70P / S5Y / E32D / S137N / G292E / K295N, K322D / S1Y / S29D / P67T / K70P / R215N / F293T, K322D / S1Y / S29D / P67T / K70L / K33E / S137N / K295N, K322D / S1Y / S29D / P67T / K70P / E32D / S137N / R215N, K322D / S1Y / S29D / P67T / K70P / E32D / K295N, K322D / S1Y / S29D / P67T / K70P / E32D / K33E / G292E / K317T, K322D / S1Y / S29D / P67T / K70P / K295N, K322D / K323S, K322D / K317T, K322D / E32D / K33E / K295N, K322D / Q50G / A184Q / G292E / K317T, K322D / E32D / K33E / K295N / K317T, K322D / E32D / K33E / K317T, K322D / K295N / K317T, K322D / E32D / K33E / P67T / K70L / K317T, K322D / P67T / K70L / K295N / K317T, K322D / E32D / K33E / Q50G / A184Q / G292E / K317T, K322D / Q50G / P67T / K70L / A184Q / G292E / K317T, K322D / E32D / K33E / Q50G / P67T / K70L / A184Q / G292E / K317T, K322D / S1Y / S29D / P67T / K70P / N24D / Q50G / K295E / , K322D / S1Y / S29D / P67T / K70P / R215N / K317T, K322D / S1Y / S29D / P67T / K70P / E32D / K33E / R215N, K322D / S1Y / S29D / P67T / K70P / E32D / K33E / R215N / K317T, K322D / Q50G / A184Q / R215N / G292E, K322D / Q50G / A184Q / R215N / G292E / K317T and K322D / S1Y / S29D / P67T / K70P / E32D / K33E / Q50G / A184Q / R215N / G292E / K317T.In a further aspect, the disclosure provides a composi on comprising a variant xylanase enzyme asdescribed herein, wherein said variant xylanase enzyme has at least 90% sequence iden ty to theamino acid sequence of SEQ ID NO:3, SEQ ID:5 or SEQ ID NO:7.In a further aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1 as described herein,wherein said amino acid subs tu on is K322D.A y Docket No. 114095-5014-WOIn an addi onal aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1 as described herein,wherein said amino acid subs tu ons are K322D / S1Y / S29D / P67T / K70P.In an addi onal aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising at least one amino acid subs tu on as compared to SEQ ID NO:1 as described herein,wherein said amino acid subs tu ons are K322D / S1Y / S29D / P67T / K70P / R215N.In a further aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising an amino acid subs tu on K322D, and further comprising at least one amino acidsubs tu on selected from the group consis ng of S1Y, S29D, S29Y, P67T, K70P, K70H, K70L, K70R,R215N, R215D, R215L, R215M, R215S, R215T, R215V, Q2P, Q2S, Q2Y, N3T, V4E, V4N, S5Q, S5Y, E8G, I22D, I22E, I22Q, I22T, N24D, N24H, N24Q, N24S, E32D, K33E, K33F, K33M, K33R, Q50A, Q50D, Q50E, Q50G, Q50N, Q50S, Q50Y, D54E, D54G, D54H, D54Y, T55A, T55D, T55K, T55L, T55N, T55P, T55R, T55S, T55V, I56T, I56V, H57E, T66A, T66P, T66R, T66V, E69D, E77R, N91Q, N91S, N91T, Q92L, Q92S, Q92W, L93N, G99D, G99R, K104R, N109E, N109F, N109T, N109W, E112A, E112C, E112D, E112F, E112G, E112I, E112K, E112L, E112N, E112P, E112R, E112S, E112T, E112V, E112W, E112Y, K116C, K116G, K116S, K127L, K127T, S137N, E144S, E144Y, K164H, S178G, S178N, I179A, I179L, I179M, I179T, I179V, A184C, A184F, A184H, A184N, A184Q, A184S, A184T, A184W, A184Y, F188A, I193T, K199R, V203I, D204H, I206V, D213T, N218K, N218Q, N218T, N218W, M241L, M241T, M241V, L247A, L247E, L247T, E251C, E251L, E251N, E251V, E252L, K256E, K256P, A263R, K264R, F266A, F266E, F266G, F266I, F266K, F266L, F266P, F266Q, F266S, F266T, F266V, F266Y, D267A, D267F, D267I, D267K, D267L, D267M, D267T, D267W, L270W, D271R, D271Y, N272H, N272P, N272T, G292A, G292D, G292E, G292N, G292S, F293T, F293V, F293W, F293Y, K295E, K295I, K295L, K295N, K295S, Y297A, Y297E, Y297Q, Y297T, K317E, K317G, K317M, K317N, K317T, K317W, E318I, E318L, E318N, E318P, E321G, K323A, K323C, K323D, K323E, K323F, K323G, K323I, K323L, K323S, K323T, K323V, E325V, R327A, R327C, R327E, R327F, R327G, R327H, R327I, R327L, R327N, R327S, R327T, R327V, R327Y, K328N and K328P.In a further aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising amino acid subs tu ons K322D / S1Y / S29D / P67T / K70P, and further comprising at leastone amino acid subs tu on selected from the group consis ng of R215N, R215D, R215L, R215M,R215S, R215T, R215V, Q2P, Q2S, Q2Y, N3T, V4E, V4N, S5Q, S5Y, E8G, I22D, I22E, I22Q, I22T, N24D, N24H, N24Q, N24S, E32D, K33E, K33F, K33M, K33R, Q50A, Q50D, Q50E, Q50G, Q50N, Q50S, Q50Y, D54E, D54G, D54H, D54Y, T55A, T55D, T55K, T55L, T55N, T55P, T55R, T55S, T55V, I56T, I56V, H57E,A y Docket No. 114095-5014-WOT66A, T66P, T66R, T66V, E69D, E77R, N91Q, N91S, N91T, Q92L, Q92S, Q92W, L93N, G99D, G99R, K104R, N109E, N109F, N109T, N109W, E112A, E112C, E112D, E112F, E112G, E112I, E112K, E112L, E112N, E112P, E112R, E112S, E112T, E112V, E112W, E112Y, K116C, K116G, K116S, K127L, K127T, S137N, E144S, E144Y, K164H, S178G, S178N, I179A, I179L, I179M, I179T, I179V, A184C, A184F, A184H, A184N, A184Q, A184S, A184T, A184W, A184Y, F188A, I193T, K199R, V203I, D204H, I206V, D213T, N218K, N218Q, N218T, N218W, M241L, M241T, M241V, L247A, L247E, L247T, E251C, E251L, E251N, E251V, E252L, K256E, K256P, A263R, K264R, F266A, F266E, F266G, F266I, F266K, F266L, F266P, F266Q, F266S, F266T, F266V, F266Y, D267A, D267F, D267I, D267K, D267L, D267M, D267T, D267W, L270W, D271R, D271Y, N272H, N272P, N272T, G292A, G292D, G292E, G292N, G292S, F293T, F293V, F293W, F293Y, K295E, K295I, K295L, K295N, K295S, Y297A, Y297E, Y297Q, Y297T, K317E, K317G, K317M, K317N, K317T, K317W, E318I, E318L, E318N, E318P, E321G, K323A, K323C, K323D, K323E, K323F, K323G, K323I, K323L, K323S, K323T, K323V, E325V, R327A, R327C, R327E, R327F, R327G, R327H, R327I, R327L, R327N, R327S, R327T, R327V, R327Y, K328N and K328P.In a further aspect, the disclosure provides a composi on comprising a variant xylanase enzymecomprising amino acid subs tu ons K322D / S1Y / S29D / P67T / K70P / R215N, and further comprising atleast one amino acid subs tu on selected from the group consis ng of Q2P, Q2S, Q2Y, N3T, V4E,V4N, S5Q, S5Y, E8G, I22D, I22E, I22Q, I22T, N24D, N24H, N24Q, N24S, E32D, K33E, K33F, K33M, K33R, Q50A, Q50D, Q50E, Q50G, Q50N, Q50S, Q50Y, D54E, D54G, D54H, D54Y, T55A, T55D, T55K, T55L, T55N, T55P, T55R, T55S, T55V, I56T, I56V, H57E, T66A, T66P, T66R, T66V, E69D, E77R, N91Q, N91S, N91T, Q92L, Q92S, Q92W, L93N, G99D, G99R, K104R, N109E, N109F, N109T, N109W, E112A, E112C, E112D, E112F, E112G, E112I, E112K, E112L, E112N, E112P, E112R, E112S, E112T, E112V, E112W, E112Y, K116C, K116G, K116S, K127L, K127T, S137N, E144S, E144Y, K164H, S178G, S178N, I179A, I179L, I179M, I179T, I179V, A184C, A184F, A184H, A184N, A184Q, A184S, A184T, A184W, A184Y, F188A, I193T, K199R, V203I, D204H, I206V, D213T, N218K, N218Q, N218T, N218W, M241L, M241T, M241V, L247A, L247E, L247T, E251C, E251L, E251N, E251V, E252L, K256E, K256P, A263R, K264R, F266A, F266E, F266G, F266I, F266K, F266L, F266P, F266Q, F266S, F266T, F266V, F266Y, D267A, D267F, D267I, D267K, D267L, D267M, D267T, D267W, L270W, D271R, D271Y, N272H, N272P, N272T, G292A, G292D, G292E, G292N, G292S, F293T, F293V, F293W, F293Y, K295E, K295I, K295L, K295N, K295S, Y297A, Y297E, Y297Q, Y297T, K317E, K317G, K317M, K317N, K317T, K317W, E318I, E318L, E318N, E318P, E321G, K323A, K323C, K323D, K323E, K323F, K323G, K323I, K323L, K323S, K323T, K323V, E325V, R327A, R327C, R327E, R327F, R327G, R327H, R327I, R327L, R327N, R327S, R327T, R327V, R327Y, K328N and K328P.A y Docket No. 114095-5014-WOIn an addi onal aspect, the disclosure provides a nucleic acid encoding the variant xylanase enzymeas described herein. In a further aspect, the disclosure provides the nucleic acid as described herein, wherein the nucleicacid is codon op mized for a host organism for expression of the variant xylanase enzyme asdescribed herein in said organism.In an addi onal aspect, the disclosure provides the nucleic acid as described herein, wherein thenucleic acid comprises a sequence that has at least 80% sequence iden ty to the sequence of SEQ IDNO:4, SEQ ID NO:6 or SEQ ID NO:8. In a further aspect, the disclosure provides the nucleic acid as described herein, wherein the nucleic acid comprises the sequence of SEQ ID NO:4, SEQ ID NO:6 or SEQ ID NO:8. In a further aspect, the disclosure provides an expression vector comprising the nucleic acid as described herein.In an addi onal aspect, the disclosure provides a host cell comprising the nucleic acid as describedherein. In a further aspect, the disclosure provides a host cell comprising the expression vector as described herein.In an addi onal aspect, the disclosure provides the host cell as described herein, wherein said hostcell is selected from the group consis ng of a bacterial cell, a fungal cell, and a yeast cell.In a further aspect, the disclosure provides a method of making a variant xylanase enzymecomprising: a) culturing the host cell as described herein under condi ons wherein said variantxylanase enzyme is expressed; and b) recovering said variant xylanase enzyme.In an addi onal aspect, the disclosure provides a composi on comprising the variant xylanaseenzyme as described herein, along with components suitable primarily for the biobleaching of paper.This composi on is par cularly e ec ve in biobleaching processes u lizing either chlorine-based orhydrogen peroxide-based agents, thereby enhancing the environmental sustainability and e ciencyof paper produc on.In a further aspect, the disclosure introduces a formula on suitable for use in the paper and pulpindustry. This formula on comprises the variant xylanase enzyme as described herein, along withA y Docket No. 114095-5014-WOone or more agents conducive to the biobleaching process. The integra on of the variant xylanaseenzyme facilitates a signi cant reduc on in the use of tradi onal, environmentally harmful bleachingagents, contribu ng to a greener, more cost-e ec ve paper manufacturing process.In an addi onal aspect, the disclosure describes a method for enhancing the biobleaching process inpaper manufacturing. Incorpora ng the variant xylanase enzyme into the paper pulp promotes thee cient and eco-friendly removal of lignin, leading to improved paper whiteness and quality, whileminimizing the ecological impact of the bleaching process.In a further aspect, while the primary focus and demonstrated applica on of the disclosure pertainto biobleaching, the poten al use of the variant xylanase enzyme for the deinking of waste paper isrecognized, based on its enzyma c proper es and ac ons. Although this speci ca on does notprovide direct examples for deinking, the mechanism of the enzyme suggests its u lity in enhancingthe sustainability and e ciency of deinking processes, especially when used in combina on withagents like laccase, thereby presen ng an avenue for future research and applica on.BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 depicts the sequence of an exemplary wild-type xylanase (also referred to as G1P xylanase herein; SEQ ID NO:1).Figure 2 depicts the tabulated fold improvement in alkaline pH ac vity of G1P-derived variants.Figure 3 depicts the tabulated fold improvement in alkaline pH ac vity of G2P-derived variants.Figure 4 depicts the tabulated fold improvement in alkaline pH ac vity of G3P-derived variants.Figure 5 depicts the tabulated fold improvement in alkaline pH speci c ac vity of selected G1P, G2Pand G3P-derived variants.Figure 6 depicts the tabulated fold improvement in applica on performance (paper whitenessincrease) of selected G1P, G2P and G3P-derived variants.Figure 7 depicts par cular variants of xylanase by posi on that demonstrate improvement asdisplayed in Figures 2−6.A y Docket No. 114095-5014-WOFigure 8 shows the Sequence Lis ng for G1P, G2P, G3P and G4P.DETAILED DESCRIPTION OF THE INVENTION A. Introduc on.Xylan is a complex heteropolysaccharide comprised of various monosaccharides, including L-arabinose, D-galactose, D-mannose, and organic acids such as ace c acid, ferulic acid, and glucuronicacid, interconnected through glycosidic and ester bonds. Its heterogeneous nature presentschallenges for breakdown, which can be e ec vely addressed by xylanases. These enzymes have thecapability to cleave the -1,4-glycosidic linkages in xylan, facilita ng its decomposi on. Xylanases arewidely distributed in nature, found in organisms ranging from mollusks and insects to a diverse arrayof microorganisms—bacteria, fungi, ac nomycetes, yeast and archaea.Xylanase has found applica ons in various industry processes. In the paper and pulp industry,xylanases, especially those that are thermostable and alkaline stable, have proven to be invaluable in biobleaching processes. These enzymes disrupt the xylan-lignin bond within pulp bers, therebyfacilita ng the removal of lignin, enhancing pulp brightness, and reducing the dependency ontradi onal chemical bleaching agents, such as chlorine and hydrogen peroxide. The use of xylanasesin this context not only mi gates the environmental footprint of chemical bleaching but alsosupports a more sustainable pulp processing technique by minimizing damage to the pulp bers.In addi on to their demonstrated e cacy in biobleaching, xylanases have also shown promise in thedeinking of waste paper, par cularly when used in combina on with laccase. The enzyma c process,by modifying the structure of xylan within paper bers, could enhance ink removal, therebyimproving both the e ciency and environmental sustainability of paper recycling processes.The present disclosure aims to introduce variant xylanases with enhanced enzyme ac vity at hightemperature and alkaline condi ons. This superior performance may result from improvements inspeci c ac vity, protein produc on, thermostability and / or alkaline stability of these variants.Moreover, selected variants demonstrate an enhanced paper bleaching e ect in industry-relevantapplica ons. The disclosure encompasses polynucleo des encoding these xylanase variants. Overall,the present disclosure promises signi cant advancements in enhancing e ciency and reducing theA y Docket No. 114095-5014-WOenvironmental impact of biobleaching and poten ally deinking processes, by harnessing the uniqueproper es of these engineered enzymes.B. De ni onsBy "protein" herein is meant at least two covalently a ached amino acids, which includes proteins,polypep des, oligopep des, and pep des. The pep dyl group generally comprise naturally occurringamino acids and pep de bonds. In addi on, polypep des may include synthe c deriva za on of oneor more side chains or termini, glycosyla on, PEGyla on, circular permuta on, cycliza on, linkers toother molecules, fusion to proteins or protein domains, and addi on of pep de tags or labels.By "amino acid" and "amino acid iden ty" as used herein is meant one of the 20 naturally occurringamino acids that are coded for by DNA and RNA.By "posi on" as used herein is meant a loca on in the sequence of a protein. In most cases unlessstated otherwise, the posi on number (which is more fully discussed below) is rela ve to the rstamino acid of the mature xylanase sequence, e.g. excluding the signal pep de.The phrase “mature polypep de” means a polypep de in its nal form excluding the signal pep deand following transla on and any post-transla onal modi ca ons, such as N-terminal processing, C-terminal trunca on, glycosyla on, phosphoryla on, etc.The phrase “mature polypep de coding sequence” refers to a polynucleo de that encodes a maturepolypep de having xylanase ac vity.By "residue" as used herein is meant a posi on in a protein and its associated amino acid iden ty.For example, Serine 133 (also referred to as Ser133 or S133) is a residue at posi on 133 in thexylanase G1P parental enzyme. The term “wild-type” xylanase refers to the sequence of the typical form of a xylanase as it occurs in nature, such as molluscs, insects and microorganisms found in nature.By "parent polypep de" as used herein is meant a star ng polypep de that is subsequently modi edto generate a variant. The parent polypep de may be a naturally occurring polypep de, or a variantor engineered version of a naturally occurring polypep de. Parent polypep de may refer to thepolypep de itself, composi ons that comprise the parent polypep de, or the amino acid sequenceA y Docket No. 114095-5014-WOthat encodes it. In the present case, some embodiments u lize xylanase G1P (wild-type) protein asset forth in SEQ ID NO:1 as the parent polypep de.The term “parent xylanase” refers to a xylanase to which an altera on is made to produce the variantxylanases of the present disclosure. The parent xylanase may be a naturally occurring (wild-type)polypep de or a variant or fragment thereof. In some embodiments, the parent polypep de of thepresent disclosure is SEQ ID NO:1. In some embodiments, the parent polypep de of the presentdisclosure is SEQ ID NO:3. In some embodiments, the parent polypep de of the present disclosure isSEQ ID NO:5.The term “variant” refers to a polypep de having xylanase ac vity and comprising an altera on or amodi ca on, e.g., a subs tu on, inser on, and / or dele on, at one or more (e.g., several) posi ons.A subs tu on means replacement of the amino acid occupying a posi on with a di erent aminoacid; a dele on means removal of the amino acid occupying a posi on; and an inser on meansadding an amino acid adjacent to and immediately following the amino acid occupying a posi on.By "variant protein" or "protein variant", as used herein is meant a protein that di ers from that of aparent protein by virtue of at least one amino acid modi ca on. Protein variant may refer to theprotein itself, a composi on comprising the protein, or the amino sequence that encodes it.Preferably, the protein variant has at least one amino acid modi ca on compared to the parentprotein, e.g. from about one to about twenty amino acid modi ca ons, and preferably from aboutone to about eleven amino acid modi ca ons compared to the parent. As described below, in someembodiments the parent polypep de is a wild-type sequence. As further discussed below, theprotein variant sequence herein will preferably exhibit at least about 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85&, 86, 87, 88%, 89%, 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98% or 99% sequence iden ty. Variant protein can refer to the variant protein itself,composi ons comprising the protein variant, or the DNA sequence that encodes it. Thus, by “variantxylanase” or “xylanase variant” herein is meant a novel xylanase that has at least one amino acidmodi ca on in the amino acid sequence as compared to a parent xylanase enzyme. As discussedherein, in some cases the parent xylanase is a second or higher genera on of a variant xylanase, suchas xylanase G2P protein (SEQ ID NO:3) or G3P protein (SEQ ID NO:5). Unless otherwise noted or as will be obvious from the context, the variant xylanases of the disclosure generally are compared tothe G1P sequence (SEQ ID NO:1). Addi onally, unless otherwise noted, the variant xylanases of thedisclosure are enzyma cally ac ve, that is, there is detectable xylanases ac vity using the xylanasesassay described in Examples below.A y Docket No. 114095-5014-WOBy "modi ca on" herein is meant an amino acid subs tu on, inser on, and / or dele on in apolypep de sequence or an altera on to a moiety chemically linked to a protein. For example, amodi ca on may be an altered carbohydrate or PEG structure a ached to a protein. By "amino acidmodi ca on" herein is meant an amino acid subs tu on, inser on, and / or dele on in a polypep desequence. For clarity, unless otherwise noted, the amino acid modi ca on is always to an amino acidcoded for by DNA, e.g. the 20 amino acids that have codons in DNA and RNA.By "amino acid subs tu on" or "subs tu on" herein is meant the replacement of an amino acid at apar cular posi on in a parent polypep de sequence with a di erent amino acid. In par cular, insome embodiments, the subs tu on is to an amino acid that is not naturally occurring at thepar cular posi on, either not naturally occurring within the organism or in any organism. Forexample, the subs tu on K322D refers to a variant polypep de, in this case a xylanase, in which thelysine at posi on 322 is replaced with aspar c acid. Mul ple muta ons are separated by forwardslash marks (“ / ”), e.g., “K322D / S1Y / S29D / P67T / K70P” represen ng subs tu ons at posi ons 322, 1,29, 67 and 70, respec vely (in some cases a “+” can be used). For clarity, a protein which has beenengineered to change the nucleic acid coding sequence but not change the star ng amino acid (forexample, exchanging CGG (encoding arginine) to CGA (s ll encoding arginine) to increase hostorganism expression levels) is not an “amino acid subs tu on”; that is, despite the crea on of a newgene encoding the same protein, if the protein has the same amino acid at the par cular posi onthat it started with, it is not an amino acid subs tu on.By "amino acid inser on" or "inser on" as used herein is meant the addi on of an amino acidsequence at a par cular posi on in a parent polypep de sequence. For example, -133E or 133Edesignates an inser on of glutamic acid a er posi on 133 and before posi on 134. Addi onally, -133ADE or 133ADE designates an inser on of AlaAspGlu a er posi on 133 and before posi on 134.By "amino acid dele on" or "dele on" as used herein is meant the removal of an amino acidsequence at a par cular posi on in a parent polypep de sequence. For example, Q12- or Q12#, Q12() or Q12del designates a dele on of glutamine at posi on 12. Addi onally, QSV12- or QSV12#designates a dele on of the sequence GlnSerVal that begins at posi on 12.The term “fragment” means a polypep de having one or more (e.g., several) amino acids absentfrom the amino and / or carboxyl terminus of a mature polypep de. A “xylanase fragment” hereinmeans a por on of an amino acid sequence depicted herein that maintains xylanase ac vity. In oneaspect, a xylanase fragment contains at least 50, at least 100, at least 150, at least 200, at least 210A y Docket No. 114095-5014-WOor at least 220 amino acid residues of a mature xylanase polypep de having zero, one or more of thesubs tu ons according to the disclosure.By "non-naturally occurring modi ca on" as used herein is meant an amino acid modi ca on that isnot found in the wild-type enzyme.The relatedness between two amino acid sequences or between two nucleo de sequences isdescribed by the parameter “sequence iden ty”. For purposes of the present disclosure, thesequence iden ty between two amino acid sequences is determined using the Needleman-Wunschalgorithm (Needleman and Wunsch, 1970, J. Mol. Biol.48: 443-453) as implemented in the Needleprogram of the EMBOSS package (EMBOSS: The European Molecular Biology Open So ware Suite,Rice et al., 2000, Trends Genet.16: 276-277), preferably 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 ofBLOSUM62) subs tu on matrix. The output of Needle labeled “longest iden ty” (obtained using the-nobrief op on) is used as the percent iden ty and is calculated as follows:(Iden cal Residues x 100) / (Length of Alignment - Total Number of Gaps in Alignment)Iden ca on of the corresponding amino acid residue in another xylanase can be determined by analignment of mul ple polypep de sequences using several computer programs including, but notlimited to, MUSCLE (mul ple sequence comparison by log-expecta on; version 3.5 or later; Edgar,2004, Nucleic Acids Research 32: 1792-1797), 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, Bioinforma cs 23: 372-374; Katoh et al., 2009, Methods in Molecular Biology537: 39-64; Katoh and Toh, 2010, Bioinforma cs 26: 1899-1900), EMBOSS EMMA employingClustalW (1.83 or later; Thompson et al., 1994, Nucleic Acids Research 22: 4673-4680), and EMBL-EBI employing Clustal Omega (Sievers and Higgins, 2014, Methods Mol Biol.2014;1079:105–16), usingtheir respec ve default parameters.When the other enzyme has diverged from the polypep de of SEQ ID NO:1 such that tradi onalsequence-based comparison fails to detect their rela onship (Lindahl and Elofsson, 2000, J. Mol. Biol.295: 613-615), other pairwise sequence comparison algorithms can be used. Greater sensi vity insequence-based searching can be a ained using search programs that u lize probabilis crepresenta ons of polypep de families (pro les) to search databases. For example, the PSI-BLASTprogram generates pro les through an itera ve database search process and is capable of detec ngremote homologs (Atschul et al., 1997, Nucleic Acids Res. 25: 3389-3402). Even greater sensi vityA y Docket No. 114095-5014-WOcan be achieved if the family or superfamily for the polypep de has one or more representa ves inthe protein structure databases. Programs such as GenTHREADER (Jones, 1999, J. Mol. Biol.287: 797-815; McGu n and Jones, 2003, Bioinforma cs 19: 874-881) u lize informa on from a variety ofsources (PSI-BLAST, secondary structure predic on, structural alignment pro les, and solva onpoten als) 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. Thesealignments can in turn be used to generate homology models for the polypep de, and such modelscan be assessed for accuracy using a variety of tools developed for that purpose. For proteins of known structure, several tools and resources are available for retrieving andgenera ng structural alignments. For example, the SCOP superfamilies of proteins have beenstructurally 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 implementa on of these algorithms can addi onally beu lized to query structure databases with a structure of interest in order to discover possiblestructural homologs (e.g., Holm and Park, 2000, Bioinforma cs 16: 566-567).In describing the variants of the present disclosure, the nomenclature described below is adapted forease of reference. The standardly accepted IUPAC single le er or three le er amino acid abbrevia onis employed and shown in Table 2.For an amino acid subs tu on, the following nomenclature is used herein: Original amino acid,posi on, subs tuted amino acid. Accordingly, the subs tu on of glycine at posi on 28 with aspar cacid is designated as “Lys322Asp” or “K322D”. Mul ple muta ons are separated by forward slashmarks (“ / ”), e.g., “K322D / S1Y / S29D / P67T / K70P”, represen ng subs tu ons at posi ons 322, 1, 29,67 and 70, respec vely.Table 2: Three-le er abbrevia ons, one-le er abbrevia ons and names of the 20 amino acids. A y Docket No. 114095-5014-WO The term “xylanase” or “xylanases” refers to one or more enzymes selected from the groupconsis ng of endo-1,4- -D-xylanases (EC 3.2.1.8), -D-xylosidases (E.C.3.2.1.37), -glucuronidase (EC3.2.1.139), acetylxylan esterase (EC 3.1.1.72), -L-arabinofuranosidases (E.C.3.2.1.55), p-coumaricesterase (3.1.1.B10) and ferulic acid esterase (EC 3.1.1.73) involved in the depolymeriza on of xylaninto simple monosaccharide and xylooligosaccharides. For purposes of the present disclosure,xylanase ac vity is determined according to the procedures described in the Examples herein, forexample, the xylanase Enzyma c Assay to determine the xylanase ac vity in Example 4.The term “coding sequence” refers to a polynucleo de, which directly speci es the amino acidsequence 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 codonsuch as TAA, TAG, or TGA. The coding sequence may be a genomic DNA, cDNA, synthe c DNA, or acombina on thereof.The term “control sequences” means nucleic acid sequences necessary for expression of apolynucleo de encoding a xylanase of the present disclosure. Each control sequence may be na ve(i.e., from the same gene) or foreign (i.e., from a di erent gene) to the polynucleo de encoding thevariant or na ve or foreign to each other. Such control sequences include, but are not limited to, aleader, polyadenyla on sequence, propep de sequence, promoter, signal pep de sequence, andtranscrip on terminator. At a minimum, the control sequences include a promoter, andtranscrip onal and transla onal stop signals. The control sequences may be provided with linkers forthe purpose of introducing speci c restric on sites facilita ng liga on of the control sequences withthe coding region of the polynucleo de encoding a variant.The term “expression” includes any step involved in the produc on of a polypep de, protein orpreprotein described herein, including, but not limited to, transcrip on, post-transcrip onalmodi ca on, transla on, post-transla onal modi ca on, and secre on.A y Docket No. 114095-5014-WOThe term “preprotein” refers to a protein precursor that is an inac ve protein or pep de andcontains a signal pep de sequence. The preprotein can be turned into a protein in an ac ve form bypost-transla onal modi ca on, such as cleaving o the signal pep de.The term “expression vector” refers to a linear or circular DNA molecule that comprises apolynucleo de encoding a polypep de, protein or preprotein as described herein, and is operablylinked to control sequences that provide for its expression.The term “subsequence” refers to a polynucleo de having one or more (e.g., several) nucleo desabsent from the 5'- and / or 3'- end of a mature polypep de coding sequence; wherein thesubsequence encodes a fragment having xylanase ac vity.By “recombinant enzyme” herein is meant that the enzyme is produced by recombinant techniques and that nucleic acid encoding the variant enzyme of the disclosure is operably linked to at least oneexogeneous (e.g. not na ve to the parent phytase) sequence, including, for examples, promoters,terminators, signal sequences, etc., as are more fully outlined below.The term “host cell” refers to any cell type that is suscep ble to transforma on, transfec on,transduc on, or the like with a nucleic acid construct or expression vector comprising apolynucleo de of the present disclosure, and that allows for expression of the enzyme. The term“host cell” encompasses any progeny of a parent cell that is not iden cal to the parent cell due tomuta ons that occur during replica on. In many embodiments, the xylanases of the disclosure(including both the xylanase and variant enzymes described herein) are not produced in the endogeneous host.The term “improved property” refers to a characteris c associated with a variant xylanase enzymedescribed herein that is improved compared to the parent xylanase enzyme. Such improvedproper es of xylanases include, but are not limited to, increased total ac vity, increased speci cac vity (e.g. the cataly c ac vity, its ability to bind to xylan, and / or its celluloly c / hydroly c ac vity),increased temperature ac vity (e.g., increased ac vity at a broad range of temperatures includinghigh temperatures), increased pH ac vity (e.g., increased ac vity at a broad range of pH includinglow pH), increased total stability, increased temperature stability (e.g., increased stability against a broad range of temperatures including high temperatures), and increased pH stability (e.g., increasedstability against a broad range of pH including low pH), formula on stability (including liquid, solidand pellets), protease stability, performance in the biobleaching and / or biodeinking process in the paper and pulp industry, etc.A y Docket No. 114095-5014-WOThe term “nucleic acid construct” refers to a nucleic acid molecule, either single-stranded or double-stranded, which is isolated from a naturally occurring gene or is modi ed to contain segments ofnucleic acids in a manner that would not otherwise exist in nature, or which is synthe c, and whichcomprises one or more control sequences.The term “operably linked” refers to a con gura on in which a construct sequence is placed at anappropriate posi on rela ve to the coding sequence of a polynucleo de such that the controlsequence directs, allows or facilitates expression of the coding sequence. The term “isolated” refers to a substance in a form or environment which does not occur in nature.Non-limi ng 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, pep de orcofactor, that is at least par ally removed from one or more or all of the naturally occurringcons tuents with which it is associated in nature; (3) any substance modi ed by the hand of manrela ve to that substance found in nature; or (4) any substance modi ed by increasing the amount ofthe substance rela ve to other components with which it is naturally associated (e.g., mul ple copiesof a gene encoding the substance; use of a stronger promoter than the promoter naturallyassociated with the gene encoding the substance, etc.). With speci c reference to isolated xylanasesof the present disclosure, the isolated xylanase is generally either: a) puri ed away from otherproteins with which it is normally associated; b) when the enzyme is in a concentra on not found innature, or c) when the enzyme is produced in a host cell that is not endogenous. By “exogeneous” in the context of nucleic acid sequences herein is meant that the exogeneouselement is not normally associated with the second element in nature and is thus an ar cial orsynthe c construct. By “exogeneous construct sequence" herein is meant a construct sequence(whether amino acid or nucleic acid sequences, although as will be appreciated by the context in which the term is used, usually refers to the nucleic acid sequence) that is not normally associated with the nucleic acid encoding the xylanase. In many embodiments, the disclosure provides nucleic acid constructs that comprise the coding sequence of an xylanase linked to exogeneous construct sequences such as an exogeneous promoter. For clarity, in general the reference to “exogeneous” is in reference to the xylanase and not the host cell. For example, if the host cell is an A. niger cell, the promoter that is operably linked to the xylanase gene may be endogeneous to A. niger but exogeneous to the xylanase. Accordingly, in some embodiments, the disclosure provides nucleic acid constructs that encode a xylanase enzyme (whether wild-type or variant) operably linked to exogeneous construct nucleic acid sequences. By “exogeneous construct sequence” herein is meantA y Docket No. 114095-5014-WOa construct sequence (whether amino acid or nucleic acid sequences, although as will be appreciated by the context in which the term is used, usually refers to the nucleic acid sequence) that is not normally associated with the nucleic acid encoding the xylanase.Suitable construct sequences that can be included in extrachromosomal or integra ng expressionvectors include, but are not limited to, selectable markers, puri caiton tags, origin(s) of replica onand regulatory sequences including but not limited to promoters (inducible and cons tua ve),enhancers, ribosomal binding sites, start codons, termina on codons, Shine-Dalgarno sequences,etc.By “selec on marker” or “selectable marker” or “selec on protein” herein is meant a protein that isintroduced into a host cell that confers a trait suitable for ar cial selec on during the growth of thehost cells, such that only those cells that contain the selectable marker grow. Thus, a selectable marker is a gene the product of which provides for biocide or viral resistance, resistance to heavymetals, prototrophy to auxotrophs, and the like. Examples of selec on markers are outlined below.Accordingly, a “selec on gene” is a nucleic acid that encodes a selec on protein.By “extrachromosomal expression vector” (also generally referred to as a “plasmid”) herein is meanta self-replica ng expression vector (generally a plasmid) that carries genes of interest, which remainswithin the cell and does not integrate into the genome of the host cell.By “integra ng expression vector” herein is meant a vector that is designed to be inserted into thegenome of the host cell, some mes referred to as “episomes”.The term “biobleaching” herein refers to the plain and ordinary meaning of the term used in the eld, such as bleaching of a material using biological means to obtain increased brightness or whiteness. The term “biodeinking” herein refers to the plain and ordinary meaning of the term used in the eld,such as removal of ink, color agents, paint, or color pigments from a medium for prin ng or wri ng,including paper and fabric, and any precursors or components thereof. C. Xylanase of the Present DisclosureAccordingly, the present disclosure provides variant xylanase with improved enzyma c ac vity thatcan be used in a variety of applica ons, most notably in the biobleaching and / or biodeinking processof paper and pulp industry.A y Docket No. 114095-5014-WOIn general, the variant xylanase of the disclosure have modi ed, improved biochemical proper es ascompared to the wild-type xylanase, “G1P” (i.e. “Genera on 1 Parent”), SEQ ID NO:1 herein, “G2P”(i.e. “Genera on 2 Parent”), which has amino acid subs tu on K322D, SEQ ID NO:3 herein, “G3P”(i.e. “Genera on 3 Parent”), which has amino acid subs tu on K322D / S1Y / S29D / P67T / K70P, SEQ IDNO:5 herein, or “G4P” (i.e. “Genera on 4 Parent”), which has amino acid subs tu onK322D / S1Y / S29D / P67T / K70P / R215N, SEQ ID NO:7 herein. The biochemical proper es of the variantxylanase that can be improved herein include, but are not limited to, total ac vity, speci c ac vity,protein produc on, thermal ac vity, thermal stability, alkaline ac vity and alkaline stability.The variant xylanases of the disclosure have one or more improved proper es as compared to G1P,G2P or G3P. By “improved” herein is meant a desirable change of at least one biochemical property.“Improved func on” can be measured as a percentage increase or decrease of a par cular ac vity, oras a “fold” change, with increases of desirable proper es (e.g. ac vity). That is, a variant xylanasemay have a 1%, 2%, 3%, 5%, or 10% increase in ac vity, as compared to G1P, G2P or G3P. In someembodiments, percentage changes are used to describe changes in biochemical ac vity of less than100%, and fold-changes are used to describe changes in biochemical ac vity of greater than 100% (ascompared to the parental enzyme, in many cases G1P, G2P or G3P). In the present disclosure,percentage changes (usually increases) of biochemical ac vity of at least about 10%, 20%, 30%, 40%,50%, 60%, 70%, 80%, 90%, 95%, 98% and 99% can be accomplished. In the present disclosure, a “foldincrease” (or decrease) is measured as compared to the star ng or parent enzyme. For example, asshown in the Figure 3, the variant K322D has 1.54 fold increase in ac vity as compared to G1P: this iscalculated by [(ac vity of variant) / (ac vity of parent)]. In many embodiments, the improvement is atleast 1.1 fold, 1.2 fold, 1.3 fold, 1.4 fold, 1.5 fold, 1.6 fold, 1.7 fold, 1.8 fold, 1.9 fold, 2 fold, 3 fold, 4 fold, 5 fold, 6 fold, 7 fold, 8 fold, 9 fold, or 10 fold or higher. In general, improvements are measured as compared to the G1P, G2P or G3P xylanase using anxylanase ac vity assay, under condi ons that are relevant to the biobleaching process of paper andpulp industry. 1. Total Ac vity IncreasesThe present disclosure provides variant xylanase with total ac vity exceeding that of G1P (wild-typexylanase, SEQ ID NO:1), G2P (variant xylanase, SEQ ID NO:3) or G3P (variant xylanase, SEQ ID NO:5).The “total ac vity” herein may be quan ed by monitoring the produc on of xylose and short-chainoligosaccharides during xylan depolymeriza on reac on at an elevated temperature (e.g. 85°C) anddesired alkaline pH (e.g. pH 8.5). Quan ca on may be performed using colorimetric assays such asA y Docket No. 114095-5014-WOthe DNS assay, as described in Example 4. Improvements in total ac vity may arise fromenhancements in speci c ac vity, protein produc on, thermoac vity, thermostability, alkalineac vity and / or alkaline stability of the variant xylanase.In many embodiments, the variant xylanases have improved total ac vity that is at least 1.1 fold, 1.2fold, 1.3 fold, 1.4 fold, 1.5 fold, 1.6 fold, 1.7 fold, 1.8 fold, 1.9 fold, 2 fold, 3 fold, 4 fold, 5 fold, 6 fold, 7 fold, 8 fold, 9 fold, or 10 fold or higher. In general, improvements are measured as compared to the G1P, G2P or G3P xylanase using anxylanase ac vity assay, under condi ons that are relevant to industrial paper biobleaching process.(i) Alkaline Ac vity IncreasesIn one aspect, the variant xylanase may exhibit increased alkaline ac vity. The “alkaline ac vity”herein may be quan ed by monitoring the produc on of xylose and short-chain oligosaccharidesduring xylan depolymeriza on reac on at the op mal temperature for the enzyme to operate and adesired alkaline pH (e.g. pH 8.5). Quan ca on may be performed using colorimetric assays such asthe DNS assay. Thus, the variant xylanases may demonstrate improved alkaline ac vity compared toG1P (wild-type xylanase, SEQ ID NO:1), G2P (variant xylanase, SEQ ID NO:3) or G3P (variant xylanase, SEQ ID NO:5),In many embodiments, the variant xylanases exhibited enhanced alkaline ac vity that is at least 1.1fold, 1.2 fold, 1.3 fold, 1.4 fold, 1.5 fold, 1.6 fold, 1.7 fold, 1.8 fold, 1.9 fold, 2 fold, 3 fold, 4 fold, 5fold, 6 fold, 7 fold, 8 fold, 9 fold, or 10 fold or higher, rela ve to G1P, G2P or G3P.(ii) Speci c Ac vity IncreasesIn another aspect, the variant xylanase may exhibited increased speci c ac vity. The “speci cac vity” herein may be determined by monitoring the produc on of xylose and short-chainoligosaccharides during xylan depolymeriza on reac on at the op mal temperature and pH for theenzyme to operate. Quan ca on may be performed using colorimetric assays such as the DNSassay, normalized for the same amount of enzyme based on protein quan ca on. Variant xylanasesdemonstrate increased ac vity per milligram of enzyme compared to G1P, G2P or G3P may exhibitedimproved speci c ac vity.In many embodiments, the variant xylanases show enhanced speci c ac vity that is at least 1.1 fold,1.2 fold, 1.3 fold, 1.4 fold, 1.5 fold, 1.6 fold, 1.7 fold, 1.8 fold, 1.9 fold, 2 fold, 3 fold, 4 fold, 5 fold, 6A y Docket No. 114095-5014-WOfold, 7 fold, 8 fold, 9 fold, or 10 fold or higher, compared to G1P, G2P or G3P. In some embodiments,the xylanase variants demonstrate increased produc on of xylose and short-chain oligosaccharidesper hour per milligram of enzyme that is at least 1.1 fold, 1.2 fold, 1.3 fold, 1.4 fold, 1.5 fold, 1.6 fold, 1.7 fold, 1.8 fold, 1.9 fold, 2 fold, 3 fold, 4 fold, 5 fold, 6 fold, 7 fold, 8 fold, 9 fold, or 10 fold or higher, compared to G1P, G2P or G3P. (iii) Protein Produc on IncreasesIn one aspect, the variant xylanases may exhibit increased protein produc on. The “proteinproduc on” herein may be determined by monitoring the protein ter of xylanase in grams per liter(g / L) using a protein quan ca on assay. Variant xylanases that demonstrate increased quan ty perliter of enzyme supernatant compared to G1P, G2P or G3P may exhibit improved protein produc on.In many embodiments, the variant xylanases show enhanced protein produc on that is at least 1.1fold, 1.2 fold, 1.3 fold, 1.4 fold, 1.5 fold, 1.6 fold, 1.7 fold, 1.8 fold, 1.9 fold, 2 fold, 3 fold, 4 fold, 5 fold, 6 fold, 7 fold, 8 fold, 9 fold, or 10 fold or higher, compared to G1P, G2P or G3P. 2. Paper Whiteness AssayIn one aspect, the variant xylanases may exhibit increased e cacy in paper biobelaching. The “paperwhiteness increase” herein may be determined by measuring the increase in paper whiteness units(PWU) or percentage increase in paper whiteness a er treatment with xylanase-containing enzymesupernatant, as described in Example 5 using a method mimicking real-world applica on in the paperand pulp industry. Variant xylanases that demonstrate a higher increase in paper whitenesscompared to G1P, G2P or G3P may indicate improved e cacy in paper biobleaching.In many embodiments, the variant xylanases show enhanced e cacy that is at least 1.1 fold, 1.2 fold,1.3 fold, 1.4 fold, 1.5 fold, 1.6 fold, 1.7 fold, 1.8 fold, 1.9 fold, 2 fold, 3 fold, 4 fold, 5 fold, 6 fold, 7 fold, 8 fold, 9 fold, or 10 fold or higher, compared to G1P, G2P or G3P. 3. XylanaseThe present disclosure provides a number of speci c variant xylanases with improved total ac vityand paper whiteness for use in the biobleaching process of paper and pulp industry.In some embodiments, the xylanase variant has one or more amino acid subs tu ons at a posi on(rela ve to G1P, SEQ ID NO:1) selected from the group consis ng of 322, 1, 29, 67, 70, 215, 2, 3, 4, 5,8, 22, 24, 32, 33, 50, 54, 55, 56, 57, 66, 69, 77, 91, 92, 93, 99, 104, 109, 112, 116, 127, 137, 144, 164,A y Docket No. 114095-5014-WO178, 179, 184, 188, 193, 199, 203, 204, 206, 213, 218, 241, 247, 251, 252, 256, 263, 264, 266, 267, 270, 271, 272, 292, 293, 295, 297, 317, 318, 321, 323, 325, 327 and 328. In some embodiments, thexylanase variant has 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or more amino acid subs tu ons at aposi on (rela ve to G1P, SEQ ID NO:1) selected from the same group.In some embodiments, the xylanase variant has one more amino acid subs tu ons selected from thegroup consis ng of K322D, K322E, K322F, K322G, K322L, K322S, K322T, K322V, K322W, S1Y, S29D,S29Y, P67T, K70P, K70H, K70L, K70R, R215N, R215D, R215L, R215M, R215S, R215T, R215V, Q2P, Q2S, Q2Y, N3T, V4E, V4N, S5Q, S5Y, E8G, I22D, I22E, I22Q, I22T, N24D, N24H, N24Q, N24S, E32D, K33E, K33F, K33M, K33R, Q50A, Q50D, Q50E, Q50G, Q50N, Q50S, Q50Y, D54E, D54G, D54H, D54Y, T55A, T55D, T55K, T55L, T55N, T55P, T55R, T55S, T55V, I56T, I56V, H57E, T66A, T66P, T66R, T66V, E69D, E77R, N91Q, N91S, N91T, Q92L, Q92S, Q92W, L93N, G99D, G99R, K104R, N109E, N109F, N109T, N109W, E112A, E112C, E112D, E112F, E112G, E112I, E112K, E112L, E112N, E112P, E112R, E112S, E112T, E112V, E112W, E112Y, K116C, K116G, K116S, K127L, K127T, S137N, E144S, E144Y, K164H, S178G, S178N, I179A, I179L, I179M, I179T, I179V, A184C, A184F, A184H, A184N, A184Q, A184S, A184T, A184W, A184Y, F188A, I193T, K199R, V203I, D204H, I206V, D213T, N218K, N218Q, N218T, N218W, M241L, M241T, M241V, L247A, L247E, L247T, E251C, E251L, E251N, E251V, E252L, K256E, K256P, A263R, K264R, F266A, F266E, F266G, F266I, F266K, F266L, F266P, F266Q, F266S, F266T, F266V, F266Y, D267A, D267F, D267I, D267K, D267L, D267M, D267T, D267W, L270W, D271R, D271Y, N272H, N272P, N272T, G292A, G292D, G292E, G292N, G292S, F293T, F293V, F293W, F293Y, K295E, K295I, K295L, K295N, K295S, Y297A, Y297E, Y297Q, Y297T, K317E, K317G, K317M, K317N, K317T, K317W, E318I, E318L, E318N, E318P, E321G, K323A, K323C, K323D, K323E, K323F, K323G, K323I, K323L, K323S, K323T, K323V, E325V, R327A, R327C, R327E, R327F, R327G, R327H, R327I, R327L, R327N, R327S, R327T, R327V, R327Y, K328N and K328P. In some embodiments, the xylanase varianthas 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or more amino acid subs tu ons selected from the samegroup.In some embodiments, the xylanase variant has an amino acid subs tu on of the lysine at posi on322 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K322D. In some embodiments, the amino acid subs tu on is K322E. In someembodiments, the amino acid subs tu on is K322F. In some embodiments, the amino acidA y Docket No. 114095-5014-WOsubs tu on is K322G. In some embodiments, the amino acid subs tu on is K322L. In someembodiments, the amino acid subs tu on is K322S. In some embodiments, the amino acidsubs tu on is K322T. In some embodiments, the amino acid subs tu on is K322V. In someembodiments, the amino acid subs tu on is K322W.In some embodiments, the variant xylanase has an amino acid subs tu on of the serine at posi on 1of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is S1Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the serine at posi on29 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is S29D. In some embodiments, the amino acid subs tu on is S29Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the proline at posi on67 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on). In some embodiments, the amino acid subs tu on is P67T.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on70 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on). In some embodiments, the amino acid subs tu on is K70P. In someembodiments, the amino acid subs tu on is K70H. In some embodiments, the amino acidsubs tu on is K70L. In some embodiments, the amino acid subs tu on is K70R.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase has an amino acid subs tu on of the arginine at posi on215 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, asparagine, aspar c acid, cysteine, glutamic acid, glutamine,glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine,tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due to possibledisul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is R215N. In some embodiments, the amino acid subs tu on is R215D. In someembodiments, the amino acid subs tu on is R215L. In some embodiments, the amino acidsubs tu on is R215M. In some embodiments, the amino acid subs tu on is R215S. In someembodiments, the amino acid subs tu on is R215T. In some embodiments, the amino acidsubs tu on is R215V.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamine atposi on 2 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline,serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine(due to possible disul de forma on). In some embodiments, the amino acid subs tu on is Q2P. Insome embodiments, the amino acid subs tu on is Q2S. In some embodiments, the amino acidsubs tu on is Q2Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the asparagine atposi on 3 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is N3T.In some embodiments, the variant xylanase has an amino acid subs tu on of the valine at posi on 4of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine and tryptophan, with some embodiments not u lizing cysteine (due to possibleA y Docket No. 114095-5014-WOdisul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is V4E. In some embodiments, the amino acid subs tu on is V4N.In some embodiments, the variant xylanase has an amino acid subs tu on of the serine at posi on 5of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is S5Q. In some embodiments, the amino acid subs tu on is S5Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 8 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is E8G.In some embodiments, the variant xylanase has an amino acid subs tu on of the isoleucine atposi on 22 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, leucine, lysine, methionine, phenylalanine, proline,serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine(due to possible disul de forma on) or proline (due to steric e ects). In some embodiments, theamino acid subs tu on is I22D. In some embodiments, the amino acid subs tu on is I22E. In someembodiments, the amino acid subs tu on is I22Q. In some embodiments, the amino acidsubs tu on is I22T.In some embodiments, the variant xylanase has an amino acid subs tu on of the asparagine atposi on 24 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is N24D. In some embodiments, the amino acid subs tu on is N24H. In someA y Docket No. 114095-5014-WOembodiments, the amino acid subs tu on is N24Q. In some embodiments, the amino acidsubs tu on is N24S.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 32 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is E32D.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on33 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K33E. In some embodiments, the amino acid subs tu on is K33F. In someembodiments, the amino acid subs tu on is K33M. In some embodiments, the amino acidsubs tu on is K33R.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamine atposi on 50 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline,serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine(due to possible disul de forma on) or proline (due to steric e ects). In some embodiments, theamino acid subs tu on is Q50A. In some embodiments, the amino acid subs tu on is Q50D. Insome embodiments, the amino acid subs tu on is Q50E. In some embodiments, the amino acidsubs tu on is Q50G. In some embodiments, the amino acid subs tu on is Q50N. In someembodiments, the amino acid subs tu on is Q50S. In some embodiments, the amino acidsubs tu on is Q50Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the aspar c acid atposi on 54 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, cysteine, glutamic acid,A y Docket No. 114095-5014-WOglutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is D54E. In some embodiments, the amino acid subs tu on is D54G. In someembodiments, the amino acid subs tu on is D54H. In some embodiments, the amino acidsubs tu on is D54Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the threonine atposi on 55 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (dueto possible disul de forma on). In some embodiments, the amino acid subs tu on is T55A. In someembodiments, the amino acid subs tu on is T55D. In some embodiments, the amino acidsubs tu on is T55K. In some embodiments, the amino acid subs tu on is T55L. In someembodiments, the amino acid subs tu on is T55N. In some embodiments, the amino acidsubs tu on is T55P. In some embodiments, the amino acid subs tu on is T55R. In someembodiments, the amino acid subs tu on is T55S. In some embodiments, the amino acidsubs tu on is T55V.In some embodiments, the variant xylanase has an amino acid subs tu on of the isoleucine atposi on 56 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, leucine, lysine, methionine, phenylalanine, proline,serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine(due to possible disul de forma on) or proline (due to steric e ects). In some embodiments, theamino acid subs tu on is I56T. In some embodiments, the amino acid subs tu on is I56V.In some embodiments, the variant xylanase has an amino acid subs tu on of the his dine atposi on 57 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is H57E.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase has an amino acid subs tu on of the threonine atposi on 66 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is T66A. In some embodiments, the amino acidsubs tu on is T66P. In some embodiments, the amino acid subs tu on is T66R. In someembodiments, the amino acid subs tu on is T66V.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 69 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is E69D.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 77 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is E77R.In some embodiments, the variant xylanase has an amino acid subs tu on of the asparagine atposi on 91 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is N91Q. In some embodiments, the amino acid subs tu on is N91S. In someembodiments, the amino acid subs tu on is N91T.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase has an amino acid subs tu on of the glutamine atposi on 92 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline,serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine(due to possible disul de forma on) or proline (due to steric e ects). In some embodiments, theamino acid subs tu on is Q92L. In some embodiments, the amino acid subs tu on is Q92S. In someembodiments, the amino acid subs tu on is Q92W.In some embodiments, the variant xylanase has an amino acid subs tu on of the leucine at posi on93 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is L93N.In some embodiments, the variant xylanase has an amino acid subs tu on of the glycine at posi on99 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is G99D. In some embodiments, the amino acid subs tu on is G99R.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on104 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K104R.In some embodiments, the variant xylanase has an amino acid subs tu on of the asparagine atposi on 109 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,A y Docket No. 114095-5014-WOglutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is N109E. In some embodiments, the amino acidsubs tu on is N109F. In some embodiments, the amino acid subs tu on is N109T. In someembodiments, the amino acid subs tu on is N109W.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 112 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine. In some embodiments, the amino acid subs tu on isE112A. In some embodiments, the amino acid subs tu on is E112C. In some embodiments, theamino acid subs tu on is E112D. In some embodiments, the amino acid subs tu on is E112F. Insome embodiments, the amino acid subs tu on is E112G. In some embodiments, the amino acidsubs tu on is E112I. In some embodiments, the amino acid subs tu on is E112K. In someembodiments, the amino acid subs tu on is E112L. In some embodiments, the amino acidsubs tu on is E112N. In some embodiments, the amino acid subs tu on is E112P. In someembodiments, the amino acid subs tu on is E112R. In some embodiments, the amino acidsubs tu on is E112S. In some embodiments, the amino acid subs tu on is E112T. In someembodiments, the amino acid subs tu on is E112V. In some embodiments, the amino acidsubs tu on is E112W. In some embodiments, the amino acid subs tu on is E112Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on116 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing proline (due tosteric e ects). In some embodiments, the amino acid subs tu on is K116C. In some embodiments,the amino acid subs tu on is K116G. In some embodiments, the amino acid subs tu on is K116S.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on127 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine,A y Docket No. 114095-5014-WOthreonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K127L. In some embodiments, the amino acid subs tu on is L127T.In some embodiments, the variant xylanase has an amino acid subs tu on of the serine at posi on137 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is S137N.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 144 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is E144S. In some embodiments, the amino acid subs tu on is E144Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on164 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K164H.In some embodiments, the variant xylanase has an amino acid subs tu on of the serine at posi on178 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is S178G. In some embodiments, the amino acid subs tu on is S178N.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase has an amino acid subs tu on of the isoleucine atposi on 179 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is I179A. In some embodiments, the amino acidsubs tu on is I179L. In some embodiments, the amino acid subs tu on is I179M. In someembodiments, the amino acid subs tu on is I179T. In some embodiments, the amino acidsubs tu on is I179V.In some embodiments, the variant xylanase has an amino acid subs tu on of the alanine at posi on184 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely arginine, asparagine, aspar c acid, cysteine, glutamic acid, glutamine,glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine,tyrosine, tryptophan and valine, with some embodiments not u lizing proline (due to steric e ects).In some embodiments, the amino acid subs tu on is A184C. In some embodiments, the amino acidsubs tu on is A184F. In some embodiments, the amino acid subs tu on is A184H. In someembodiments, the amino acid subs tu on is A184N. In some embodiments, the amino acidsubs tu on is A184Q. In some embodiments, the amino acid subs tu on is A184S. In someembodiments, the amino acid subs tu on is A184T. In some embodiments, the amino acidsubs tu on is A184W. In some embodiments, the amino acid subs tu on is A184Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the phenylalanine atposi on 188 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is F188A.In some embodiments, the variant xylanase has an amino acid subs tu on of the isoleucine atposi on 193 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, leucine, lysine, methionine, phenylalanine, proline,A y Docket No. 114095-5014-WOserine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine(due to possible disul de forma on) or proline (due to steric e ects). In some embodiments, theamino acid subs tu on is I193T.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on199 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, leucine, methionine, phenylalanine, proline, serine, threonine, tyrosine,tryptophan and valine, with some embodiments not u lizing cysteine (due to possible disul deforma on) or proline (due to steric e ects). In some embodiments, the amino acid subs tu on isK199R.In some embodiments, the variant xylanase has an amino acid subs tu on of the valine at posi on203 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, leucine, methionine, phenylalanine, proline, serine, threonine, tyrosineand tryptophan, with some embodiments not u lizing cysteine (due to possible disul de forma on)or proline (due to steric e ects). In some embodiments, the amino acid subs tu on is V203I.In some embodiments, the variant xylanase has an amino acid subs tu on of the aspar c acid atposi on 204 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is D204H.In some embodiments, the variant xylanase has an amino acid subs tu on of the isoleucine atposi on 206 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, leucine, lysine, methionine, phenylalanine, proline,serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine(due to possible disul de forma on) or proline (due to steric e ects). In some embodiments, theamino acid subs tu on is I206V.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase has an amino acid subs tu on of the aspar c acid atposi on 213 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, cysteine, glutamic acid,glutamine, glycine, his dine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine,tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due to possibledisul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is D213T.In some embodiments, the variant xylanase has an amino acid subs tu on of the asparagine atposi on 218 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is N218K. In some embodiments, the amino acid subs tu on is N218Q. In someembodiments, the amino acid subs tu on is N218T. In some embodiments, the amino acidsubs tu on is N218W.In some embodiments, the variant xylanase has an amino acid subs tu on of the methionine atposi on 241 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is M241L. In some embodiments, the amino acid subs tu on is M241T. In someembodiments, the amino acid subs tu on is M241V.In some embodiments, the variant xylanase has an amino acid subs tu on of the leucine at posi on247 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, lysine, methionine, phenylalanine, proline, serine, threonine,tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due to possibledisul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is L247A. In some embodiments, the amino acid subs tu on is L247E. In someembodiments, the amino acid subs tu on is L247T.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 251 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing proline (due tosteric e ects). In some embodiments, the amino acid subs tu on is E251C. In some embodiments,the amino acid subs tu on is E251L. In some embodiments, the amino acid subs tu on is E251N. Insome embodiments, the amino acid subs tu on is E251V.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 252 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is E252L.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on256 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamine,glycine, his dine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, tyrosine,tryptophan and valine, with some embodiments not u lizing cysteine (due to possible disul deforma on). In some embodiments, the amino acid subs tu on is K256E. In some embodiments, theamino acid subs tu on is K256P.In some embodiments, the variant xylanase has an amino acid subs tu on of the alanine at posi on263 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely arginine, asparagine, aspar c acid, cysteine, glutamine, glycine,his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine,tryptophan and valine, with some embodiments not u lizing cysteine (due to possible disul deforma on) or proline (due to steric e ects). In some embodiments, the amino acid subs tu on isA263R.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on264 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,A y Docket No. 114095-5014-WOglutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K264R.In some embodiments, the variant xylanase has an amino acid subs tu on of the phenylalanine atposi on 266 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on). In some embodiments, the amino acid subs tu on isF266A. In some embodiments, the amino acid subs tu on is F266E. In some embodiments, theamino acid subs tu on is F266G. In some embodiments, the amino acid subs tu on is F266I. Insome embodiments, the amino acid subs tu on is F266K. In some embodiments, the amino acidsubs tu on is F266L. In some embodiments, the amino acid subs tu on is F266P. In someembodiments, the amino acid subs tu on is F266Q. In some embodiments, the amino acidsubs tu on is F266S. In some embodiments, the amino acid subs tu on is F266T. In someembodiments, the amino acid subs tu on is F266V. In some embodiments, the amino acidsubs tu on is F266Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the aspar c acid atposi on 267 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is D267A. In some embodiments, the amino acidsubs tu on is D267F. In some embodiments, the amino acid subs tu on is D267I. In someembodiments, the amino acid subs tu on is D267K. In some embodiments, the amino acidsubs tu on is D267L. In some embodiments, the amino acid subs tu on is D267M. In someembodiments, the amino acid subs tu on is D267T. In some embodiments, the amino acidsubs tu on is D267W.In some embodiments, the variant xylanase has an amino acid subs tu on of the leucine at posi on270 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyA y Docket No. 114095-5014-WOoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is L270W.In some embodiments, the variant xylanase has an amino acid subs tu on of the aspar c acid atposi on 271 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is D271R. In some embodiments, the amino acidsubs tu on is D271Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the asparagine atposi on 272 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on). In some embodiments, the amino acid subs tu on isN272H. In some embodiments, the amino acid subs tu on is N272P. In some embodiments, theamino acid subs tu on is N272T.In some embodiments, the variant xylanase has an amino acid subs tu on of the glycine at posi on292 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is G292A. In some embodiments, the amino acid subs tu on is G292D. In someembodiments, the amino acid subs tu on is G292E. In some embodiments, the amino acidsubs tu on is G292N. In some embodiments, the amino acid subs tu on is G292S.In some embodiments, the variant xylanase has an amino acid subs tu on of the phenylalanine atposi on 293 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19A y Docket No. 114095-5014-WOnaturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is F293T. In some embodiments, the amino acidsubs tu on is F293V. In some embodiments, the amino acid subs tu on is F293W. In someembodiments, the amino acid subs tu on is F293Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on295 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K295E. In some embodiments, the amino acid subs tu on is K295I. In someembodiments, the amino acid subs tu on is K295L. In some embodiments, the amino acidsubs tu on is K295N. In some embodiments, the amino acid subs tu on is K295S.In some embodiments, the variant xylanase has an amino acid subs tu on of the tyrosine at posi on297 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is Y297A. In some embodiments, the amino acid subs tu on is Y297E. In someembodiments, the amino acid subs tu on is Y297Q. In some embodiments, the amino acidsubs tu on is Y297T.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on317 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on) or proline (due to steric e ects). In some embodiments, the amino acidsubs tu on is K317E. In some embodiments, the amino acid subs tu on is K317G. In someA y Docket No. 114095-5014-WOembodiments, the amino acid subs tu on is K317M. In some embodiments, the amino acidsubs tu on is K317N. In some embodiments, the amino acid subs tu on is K317T. In someembodiments, the amino acid subs tu on is K317W.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 318 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on). In some embodiments, the amino acid subs tu on isE318I. In some embodiments, the amino acid subs tu on is E318L. In some embodiments, theamino acid subs tu on is E318N. In some embodiments, the amino acid subs tu on is E318P.In some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 321 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is E321G.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on323 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing proline (due tosteric e ects). In some embodiments, the amino acid subs tu on is K323A. In some embodiments,the amino acid subs tu on is K323C. In some embodiments, the amino acid subs tu on is K323D. Insome embodiments, the amino acid subs tu on is K323E. In some embodiments, the amino acidsubs tu on is K323F. In some embodiments, the amino acid subs tu on is K323G. In someembodiments, the amino acid subs tu on is K323I. In some embodiments, the amino acidsubs tu on is K323L. In some embodiments, the amino acid subs tu on is K323S. In someembodiments, the amino acid subs tu on is K323T. In some embodiments, the amino acidsubs tu on is K323V.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase has an amino acid subs tu on of the glutamic acid atposi on 325 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19naturally occurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine,glutamic acid, glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine,proline, serine, threonine, tyrosine, tryptophan and valine, with some embodiments not u lizingcysteine (due to possible disul de forma on) or proline (due to steric e ects). In someembodiments, the amino acid subs tu on is E325V.In some embodiments, the variant xylanase has an amino acid subs tu on of the arginine at posi on327 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing proline (due tosteric e ects). In some embodiments, the amino acid subs tu on is R327A. In some embodiments,the amino acid subs tu on is R327C. In some embodiments, the amino acid subs tu on is R327E. Insome embodiments, the amino acid subs tu on is R327F. In some embodiments, the amino acidsubs tu on is R327G. In some embodiments, the amino acid subs tu on is R327H. In someembodiments, the amino acid subs tu on is R327I. In some embodiments, the amino acidsubs tu on is R327L. In some embodiments, the amino acid subs tu on is R327N. In someembodiments, the amino acid subs tu on is R327S. In some embodiments, the amino acidsubs tu on is R327T. In some embodiments, the amino acid subs tu on is R327V. In someembodiments, the amino acid subs tu on is R327Y.In some embodiments, the variant xylanase has an amino acid subs tu on of the lysine at posi on328 of SEQ ID NO:1. In some embodiments, the subs tu on is with any other of the 19 naturallyoccurring amino acids, namely alanine, arginine, asparagine, aspar c acid, cysteine, glutamic acid,glutamine, glycine, his dine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine,threonine, tyrosine, tryptophan and valine, with some embodiments not u lizing cysteine (due topossible disul de forma on). In some embodiments, the amino acid subs tu on is K328N. In someembodiments, the amino acid subs tu on is K328P.In some embodiments, the variant xylanase enzyme has one or more amino acid subs tu ons at 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 or 30 ofthe posi ons of SEQ ID NO:1 as described above.A y Docket No. 114095-5014-WOIn some embodiments, the variant xylanase enzymes of the disclosure have at least 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% sequence iden ty to SEQ ID NO:1. In someembodiments, the variant xylanase enzyme is SEQ ID NO:3. In some embodiments, the variant enzyme is SEQ ID NO:5. In some embodiments, the variant enzyme is SEQ ID NO:7.The amino acid changes that may be present in addi on to the speci c subs tu ons describedherein may be of a minor nature, that is conserva ve amino acid subs tu ons or inser ons that donot signi cantly a ect the folding and / or ac vity of the protein; small dele ons, typically of 1 toabout 30 amino acids; small amino- or carboxyl-terminal extensions, such as an amino-terminalmethionine residue; a small linker pep de of up to about 20 to about 25 residues; or a smallextension that facilitates puri ca on by changing net charge or another func on, such as a poly-his dine tract, an an genic epitope or a binding domain.Examples of conserva ve subs tu ons are within the groups of basic amino acids (arginine, lysineand his dine), acidic amino acids (glutamic acid and aspar c acid), polar amino acids (glutamine andasparagine), hydrophobic amino acids (leucine, isoleucine and valine), aroma c amino acids(phenylalanine, tryptophan and tyrosine), and small amino acids (glycine, alanine, serine, threonineand methionine). Amino acid subs tu ons that do not generally alter speci c ac vity are known inthe art and are described, for example, by H. Neurath and R.L. Hill, 1979, In, The Proteins, AcademicPress, New York. Common subs tu ons 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 / Ile, Leu / Ala, Ala / Glu, and Asp / Gly.In some embodiments, the disclosure relates to variant xylanases having improved proper es, suchas increased total ac vity, speci c ac vity, protein produc on, thermal ac vity, thermal stability,alkaline ac vity, alkaline stability, temperature stability, pH stability, steam stability, storage stability,and so on. These improved proper es are par cularly bene cial for various industry applica ons.The composi ons and methods of the disclosure thus pertain to variant xylanases exhibi ngenhanced e cacy in the biobleaching process and poten ally in the biodeinking process of the paperand pulp industry. Biobleaching refers to the removal of lignin and other colorants from pulp usingbiological agents, while biodeinking involves the enzyma c removal of ink from waste paper pulp.The improved e cacy of the variant xylanases o ers promising prospects for enhancing thee ciency and sustainability of paper and pulp processing.D. Nucleic Acids of the Present DisclosureA y Docket No. 114095-5014-WOThe present disclosure addi onal provides nucleic acids encoding the variant xylanases. As will beappreciated by those in the art, due to the degeneracy of the gene c code, an extremely largenumber of nucleic acids may be made, all of which encode the variant xylanases of the presentdisclosure. Thus, having iden ed a par cular amino acid sequence, those skilled in the art couldmake any number of di erent nucleic acids, by simply modifying the sequence of one or morecodons in a way which does not change the amino acid sequence of the protein. Thus, providing theamino acid sequence allows the genera on of a very large number of di erent nucleic acidsequences encoding the proteins.In some embodiments, speci c variant xylanases are encoded by speci c nucleic acid sequences, asare listed in Figure 8. In some embodiments, speci c variant xylanases are encoded by a nucleic acidsequence having at least about 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 85, 86, 87,88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100% iden ty to SEQ ID NO:2.As is known in the art, the nucleic acids encoding the components of the disclosure can be incorporated into expression vectors as is known in the art, and depending on the host cells used toproduce the heterodimeric an bodies of the disclosure. Generally the nucleic acids are operablylinked to any number of regulatory elements (promoters, origin of replica on, selectable markers,ribosomal binding sites, inducers, etc.). The expression vectors can be extra-chromosomal orintegra ng vectors.The nucleic acids and / or expression vectors of the disclosure are then transformed into any numberof di erent types of host cells as is well known in the art, including mammalian, bacterial, yeast,insect and / or fungal cells, with bacteria, yeast and fungi nding use in many embodiments. 1. Prepara on of VariantsThe nucleic acids encoding the variant xylanases of the disclosure can be prepared using anymutagenesis procedure known in the art, such as site-directed mutagenesis and synthe c geneconstruc on as are well known in the art.Synthe c gene construc on entails in vitro synthesis of a designed polynucleo de molecule toencode a polypep de of interest. Gene synthesis can be performed u lizing a number of techniques,such as the mul plex microchip-based technology described by Tian et al. (2004, Nature 432: 1050-1054) and similar technologies wherein oligonucleo des are synthesized and assembled upon photo-programmable micro uidic chips. A preferred technique is GenScript®.A y Docket No. 114095-5014-WO2. Regulatory sequencesThe present disclosure also relates to nucleic acid constructs comprising a polynucleo de encoding avariant of the present disclosure operably linked to one or more control sequences that direct theexpression of the coding sequence in a suitable host cell under condi ons compa ble with thecontrol sequences.The polynucleo de may be manipulated in a variety of ways to provide for expression of a variant.Manipula on of the polynucleo de prior to its inser on into a vector may be desirable or necessarydepending on the expression vector. The techniques for modifying polynucleo des u lizingrecombinant DNA methods are well known in the art.The control sequence may be a promoter, a polynucleo de which is recognized by a host cell forexpression of the polynucleo de. The promoter contains transcrip onal control sequences thatmediate the expression of the variant. The promoter may be any polynucleo de that showstranscrip onal ac vity in the host cell including mutant, truncated, and hybrid promoters, and maybe obtained from genes encoding extracellular or intracellular polypep des either homologous orheterologous to the host cell. Promoters for bacteria, yeast and fungi are well known in the art. Exemplary operons for expressionin lac c acid bacteria include S. thermophilus lactose operons or L. lac c lac ABCDFEGX operons,which have been successfully used to induce foreign gene expression in hosts (see, e.g., Simons et al.,1993, J. Bact. 175: 5186-5175; Mollet et al., 1993, J. Bact. 175: 4315-4324). Non-limi ng addi onalexamples of cons tu ve promoters for bacteria include lac promoter, trp promoter, tac promoter, T7promoter, erm promoter, p promoter, nit promoter, and Sp6 promoter. Exemplary promoters for yeasts include, but not limited to, AOX1 promoter, ADH promoter, PH05 promoter, GAL1 and GAL10 promoters, PKG promoter and GAP promoter. Other useful promoters for yeast host cells are described by Romanoset al., 1992, Yeast 8: 423-488. Moreover, examples of useful promoters for fungi vectors include, but not limit to, Aspergillus niger GLA promoter, Aspergillus nidulans GPDpromoter, those derived from Aspergillus nidulans glycoly c genes, such as the adh3 promoter(McKnight et al., EMBO J.4:2093-2099,1985). 3. Codon Op miza onCodon op miza on can be employed with any of the variant xylanase polypep des of the presentdisclosure, in order to op mize expression in the host cell employed. Such methods are well knownin the art and described in, for example, WO 2007 / 142954. In heterologous expression systems,A y Docket No. 114095-5014-WO In some embodiments, reduced heterologous protein expression results from a rare codon-inducedtransla onal pause. A rare codon-induced transla onal pause includes the presence of codons in thepolynucleo de of interest that are rarely used in the host organism can have a nega ve e ect onprotein transla on due to their scarcity in the available tRNA pool. One method of improving op maltransla on in the host organism includes performing includes performing codon op miza on whichcan result in rare host codons being modi ed in the synthe c polynucleo de sequence.In some embodiments, reduced heterologous protein expression results from alternate transla onalini a on. Alternate transla onal ini a on can include a synthe c polynucleo de sequenceinadvertently containing mo fs capable of func oning as a ribosome binding site (RBS). These sitescan result in ini a ng transla on of a truncated protein from a gene-internal site. One method ofreducing the possibility of producing a truncated protein, which can be di cult to remove duringpuri ca on, includes modifying puta ve internal RBS sequences from an op mized polynucleo desequence. In some embodiments, reduced heterologous protein expression occurs through repeat-inducedpolymerase slippage. Repeat-induced polymerase slippage involves nucleo de sequence repeats thathave been shown to cause slippage or stu ering of DNA polymerase which can result in frameshimuta ons. Such repeats can also cause slippage of RNA polymerase. In an organism with a high G+Ccontent bias, there can be a higher degree of repeats composed of G or C nucleo de repeats.Therefore, one method of reducing the possibility of inducing RNA polymerase slippage includesaltering extended repeats of G or C nucleo des.In some embodiments, reduced heterologous protein expression occurs through interferingsecondary structures. Secondary structures can sequester the RBS sequence or ini a on codon andhave been correlated to a reduc on in protein expression. Stem-loop structures can also be involvedA y Docket No. 114095-5014-WOin transcrip onal pausing and a enua on. An op mized polynucleo de sequence can containminimal secondary structures in the RBS and gene coding regions of the nucleo de sequence toallow for improved transcrip on and transla on.In some embodiments, restric on sites can a ect heterologous protein expression. By modifyingrestric on sites that could interfere with subsequent sub-cloning of transcrip on units into hostexpression vectors a polynucleo de sequence can be op mized.Op mizing a DNA sequence can nega vely or posi vely a ect gene expression or protein produc on.For example, modifying a less-common codon with a more common codon may a ect the half-life ofthe mRNA or alter its structure by introducing a secondary structure that interferes with transla onof the message. It may therefore be necessary, in certain instances, to alter the op mized message.All or a por on of a gene can be op mized. In some embodiments, the desired modula on ofexpression is achieved by op mizing essen ally the en re gene. In other embodiments, the desiredmodula on will be achieved by op mizing part but not all of the gene.The codon usage of any coding sequence can be adjusted to achieve a desired property, for examplehigh levels of expression in a speci c cell type. The star ng point for such an op miza on may be acoding sequence with 100% common codons, or a coding sequence which contains a mixture of common and non-common codons.Two or more candidate sequences that di er in their codon usage can be generated and tested todetermine if they possess the desired property. Candidate sequences can be evaluated by using a computer to search for the presence of regulatory elements, such as silencers or enhancers, and to search for the presence of regions of coding sequence which could be converted into such regulatoryelements by an altera on in codon usage. Addi onal criteria can include enrichment for par cularnucleo des, e.g., A, C, G or U, codon bias for a par cular amino acid, or the presence or absence ofpar cular mRNA secondary or ter ary structure. Adjustment to the candidate sequence can be madebased on a number of such criteria.Promising candidate sequences are constructed and then evaluated experimentally. Mul plecandidates may be evaluated independently of each other, or the process can be itera ve, either byusing the most promising candidate as a new star ng point, or by combining regions of two or morecandidates to produce a novel hybrid. Further rounds of modi ca on and evalua on can beincluded.A y Docket No. 114095-5014-WOModifying the codon usage of a candidate sequence can result in the crea on or destruc on ofeither a posi ve or nega ve element. In general, a posi ve element refers to any element whosealtera on or removal from the candidate sequence could result in a decrease in expression of thetherapeu c protein, or whose crea on could result in an increase in expression of a therapeu cprotein. For example, a posi ve element can include an enhancer, a promoter, a downstreampromoter element, a DNA binding site for a posi ve regulator (e.g., a transcrip onal ac vator), or asequence responsible for impar ng or modifying an mRNA secondary or ter ary structure. Anega ve element refers to any element whose altera on or removal from the candidate sequencecould result in an increase in expression of the therapeu c protein, or whose crea on would result ina decrease in expression of the therapeu c protein. A nega ve element includes a silencer, a DNAbinding site for a nega ve regulator (e.g., a transcrip onal repressor), a transcrip onal pause site, ora sequence that is responsible for impar ng or modifying an mRNA secondary or ter ary structure.In general, a nega ve element arises more frequently than a posi ve element. Thus, any change incodon usage that results in an increase in protein expression is more likely to have arisen from thedestruc on of a nega ve element rather than the crea on of a posi ve element. In addi on,altera on of the candidate sequence is more likely to destroy a posi ve element than create aposi ve element. In some embodiments, a candidate sequence is chosen and modi ed so as toincrease the produc on of a therapeu c protein. The candidate sequence can be modi ed, e.g., bysequen ally altering the codons or by randomly altering the codons in the candidate sequence. Amodi ed candidate sequence is then evaluated by determining the level of expression of theresul ng therapeu c protein or by evalua ng another parameter, e.g., a parameter correlated to thelevel of expression. A candidate sequence which produces an increased level of a therapeu c proteinas compared to an unaltered candidate sequence is chosen.In some embodiments, one or a group of codons can be modi ed, e.g., without reference to proteinor message structure and tested. Alterna vely, one or more codons can be chosen on a message-level property, e.g., loca on in a region of predetermined, e.g., high or low GC content, loca on in aregion having a structure such as an enhancer or silencer, loca on in a region that can be modi ed tointroduce a structure such as an enhancer or silencer, loca on in a region having, or predicted tohave, secondary or ter ary structure, e.g., intra-chain pairing, inter-chain pairing, loca on in a regionlacking, or predicted to lack, secondary or ter ary structure, e.g., intra-chain or inter-chain pairing. Apar cular modi ed region is chosen if it produces the desired result.Methods which systema cally generate candidate sequences are useful. For example, one or agroup, e.g., a con guous block of codons, at various posi ons of a synthe c nucleic acid sequenceA y Docket No. 114095-5014-WOcan be modi ed with common codons (or with non common codons, if for example, the star ngsequence has been op mized) and the resul ng sequence evaluated. Candidates can be generatedby op mizing (or de-op mizing) a given “window” of codons in the sequence to generate a rstcandidate, and then moving the window to a new posi on in the sequence, and op mizing (or de-op mizing) the codons in the new posi on under the window to provide a second candidate.Candidates can be evaluated by determining the level of expression they provide, or by evalua nganother parameter, e.g., a parameter correlated to the level of expression. Some parameters can beevaluated by inspec on or computa onally, e.g., the possession or lack thereof of high or low GCcontent; a sequence element such as an enhancer or silencer; secondary or ter ary structure, e.g.,intra-chain or inter-chain paring.In some embodiments, the op mized nucleic acid sequence can express the variant xylanasepolypep de of the disclosure, at a level which is at least about 110%, 150%, 200%, 500%, 1,000%,5,000% or even 10,000% of that expressed by nucleic acid sequence that has not been op mized.Star ng with the amino acid sequence of a variant xylanase, a candidate DNA sequence can bedesigned. During the design of the synthe c DNA sequence, the frequency of codon usage can becompared to the codon usage of the host expression organism and rare host codons can be modi edin the synthe c sequence. Addi onally, the synthe c candidate DNA sequence can be modi ed inorder to remove undesirable enzyme restric on sites and add or alter any desired signal sequences,linkers or untranslated regions. The synthe c DNA sequence can be analyzed for the presence ofsecondary structure that may interfere with the transla on process, such as G / C repeats and stem-loop structures. Before the candidate DNA sequence is synthesized, the op mized sequence designcan be checked to verify that the sequence correctly encodes the desired amino acid sequence. Finally, the candidate DNA sequence can be synthesized using DNA synthesis techniques, such as those known in the art. In some embodiments, the general codon usage in a host organism, such as any of those describedherein, can be u lized to op mize the expression of the heterologous polynucleo de sequence inthe host organism. The percentage and distribu on of codons that rarely would be considered aspreferred for a par cular amino acid in the host expression system can be evaluated. Values of 5%and 10% usage can be used as cuto values for the determina on of rare codons.4. Host Cells and Produc on StrainsA y Docket No. 114095-5014-WOIn one aspect, the present disclosure relates to an expression vector comprising the nucleic acid encoding the variant xylanase described herein. In another aspect, the present disclosure also relates to a host cell comprising the expression vector. In some embodiments, the host cell is bacteria. In some embodiments, the host cell is yeast. In some embodiments, the host cell is fungi. In some embodiments, the host cell may be bacteria, including but not limited to E. coli, Bacillus. In some embodiments, the host cell may be yeast, including but not limited to Saccharomyces cerevisiae, Pichia. In some embodiments, the host cell may be fungi, including but not limited to A. niger, T. reseei, or Myceliophthora thermophila.The expression vector may be any of integra on vectors which are to be integrated into genome orautonomously replica ng plasmids in the selected host. In one embodiment, the vector can be stablymaintained in the introduced cell, with the variant xylanase gene supported thereon in a t state forexpression. The expression vector may be selected to be suitable for the speci c host cells to whichthe vector is introduced. Speci c examples available for use include but not limit to pBR322,pACYC184, pUC18, pKK223-2, pHSG398 (Takara Bio Inc.), pTrcHis (Invitrogen Corpora on) and pET11a(Stratagene Corpora on) in the case where Escherichia coli is used as a host; pBBR122 (Mobiotech)and pBHR1 (Mobiotech) for the other gram-nega ve bacteria; pHW1520 (Mobiotech) andpHY300PLK (Takara Bio Inc.) for Bacillus; pSH19 (Herai et al., Proc. Natl. Acad. Sci., 101, 14031-14035, 2004), pIJ702 (John Innes Centre), pIJ943 (John Innes Centre), pIJ8600 (John Innes Centre), pIJ602 (John Innes Centre), pTip-vectors (Nakashima et al., Appli. Environ. Microbiol., 70, 5557-5568, 2004),pTYM19 (Onaka et al., J. An biot., 56, 950-956, 2003) for ac nomycetes; pPICZα and pPIC9 (ThermoFisher Scien c) for Pichia, and pAO815 (Invitrogen Corpora on), pAUR101 (Takara Bio Inc.),pAUR123 (Takara Bio Inc.) and pAUR316 (Takara Bio Inc.) for fungi. In another aspect, the present disclosure also relates to a method of expressing the variant xylanase in the host cell. In another aspect, the present disclosure also relates to a method of making thevariant xylanase comprising culturing the host cell under condi ons wherein said variant xylanase isproduced, and recovering said variant xylanase.The culture of a transformed organism may be performed in the medium which can be a nutri vemedium of the transformed host cell without a ec ng the transforma on of the variant xylanase.Such a medium comprises an appropriate carbon source, nitrogen source, inorganic salt, natural organic nutrient and the like. As a carbon source, glucose, fructose, glycerol, sorbitol, organic acidscan be used individually or in combina on. The concentra on of the carbon source is not par cularlylimited and may be 1 to 10 %. As a nitrogen source, ammonium, urea, ammonium sulfate,A y Docket No. 114095-5014-WOammonium nitrate, ammonium acetate and the like can be used individually or in combina on oftwo or more members thereof. As an inorganic salt, salts such as monopotassium phosphate, dipotassium phosphate, magnesium sulfate, manganese sulfate and ferrous sulfate can be used. Inaddi on, as an organic nutrient source having growth-promo ng e ects of the bacteria to be used,peptone, meat extract, yeast extract, corn steep liquor and casamino acids can be used and furthermore, a small amount vitamins and nucleic acids may be contained in the medium. 5. Xylanase Formula ons and UsesAs will be appreciated by those in the art, the formula on of the variant xylanases of the disclosuredepends on its end use and the associated condi ons. Suitable formula ons for the variant xylanasesof the disclosure include liquid formula ons, dried formula ons (including spray dried formula ons),powdered formula ons, granular formula ons, and pelleted formula ons.In some embodiments, the enzyme composi on (i.e., polypep de composi ons) of the presentdisclosure can be in any form suitable for use, such as, for example, a crude fermenta on broth withor without cells removed, a cell lysate with or without cellular debris, a semi-puri ed or puri edenzyme composi on, or a host cell, as a source of the enzymes.In some embodiments, the enzyme composi on may be a dry powder or granulate, a non-dus nggranulate, a liquid, a stabilized liquid, or a stabilized protected enzyme. Liquid enzyme composi onsmay, for instance, be stabilized by adding stabilizers such as a sugar, a sugar alcohol or anotherpolyol, and / or lac c acid or another organic acid according to established processes.In some embodiments, the dosage of the polypep de composi on of the disclosure and othercondi ons under which the composi on is used may be determined on the basis of methods knownin the art.The above composi ons are suitable for use in the biobleaching and biodeinking process of thepaper and pulp industry. EXAMPLES Example 1: Design and Construc on of Xylanase Libraries and Speci c VariantsA y Docket No. 114095-5014-WOThe wild-type xylanase, or G1P, from Thermotoga mari ma (h ps: / / www.uniprot.org / accessionnumber: Q9WXS5) was obtained by gene synthesis from GeneWiz (h ps: / / www.genewiz.com / ). Tofurther improve the total ac vity of the xylanase under thermal and alkaline condi on, mul plevariant libraries and speci c variants were designed based on experimental results, as well as in-depth sequence and structure analysis. Mutagenesis and subsequent cloning of the mutated genes into suitable expression vectors wereperformed using established techniques. The resul ng variants were expressed in a host organismop mized for xylanase variant expression.Example 2: Prepara on of Variant Xylanases in Micro ter PlatesRecombinant host strains containing variant xylanase genes were cultured from single colonies in 24-or 96-well micro ter plates containing a speci c growth medium. Cultures were incubated overnightat 30°C with 200 rpm shaking and maintained at 85% rela ve humidity. These primary cultures werethen diluted and inoculated into fresh plates with iden cal media.The cultures underwent further incuba on under the same condi ons and were induced periodicallywith an inducer compound over a span of up to 120 hours to maximize variant expression.Culture supernatants were subsequently decanted into round-bo om plates for storage at -20°C,preserving protein integrity prior to analysis via ac vity assays.Example 3: Prepara on of Variant Xylanases in Large ScaleSelected variant strains were grown in shake asks with ba ed bo om containing a speci c growthmedium. Cultures were incubated overnight at 30°C with 200 rpm shaking and maintained at 85%rela ve humidity. These primary cultures were then diluted and inoculated into fresh shake askswith ba ed bo om with iden cal media. The cultures underwent further incuba on under the samecondi ons and were induced periodically with an inducer compound up to 120 hours to maximizevariant expression. Selected variant strains were grown in fermenters. The transformed host organisms were cultured ina fermenta on medium that was tailored for the growth requirements of the speci c host.A y Docket No. 114095-5014-WOThroughout the fermenta on process, cri cal parameters such as temperature, pH, aera on,agita on, and feeding schedules were me culously controlled to maximize enzyme produc on. Theprogress of the fermenta on was monitored by measuring the biomass concentra on, and periodicsampling was conducted to evaluate protein expression levels. Example 4: Evalua on of Variant Xylanases Alkaline pH Ac vity in Micro ter PlatesThe enzyme dosing response assay (EDR) is conducted in a 96-well plate using posi ve controlsupernatant to iden fy the appropriate dilu on factor for the assay, aiming for an op cal density(OD) of 0.4-0.6 at 540 nm. Following the EDR, variant xylanase samples are diluted in costar plates,mixed with 50 mM pH 8.5 Tris-HCl bu er, and then transferred to BioRad PCR plates with the xylansubstrate at the same pH. The plates are sealed, heated, and shaken for speci c dura ons tofacilitate the enzyma c reac on at pH 8.5 and 85°C. Subsequently, DNS reagent is added, and theplates undergo a DNS reac on in a PCR machine. A er mixing and centrifuging, the samples aretransferred to NUNC plates, mixed with water, and read at 540 nm in a plate reader to assess theenzyme ac vity. This process involves several steps of mixing, hea ng, and centrifuga on to ensureaccurate measurement of enzyme ac vity. The results, illustra ng the improved alkaline pH ac vityof all variants in comparison to their respec ve parent enzyme (G1P, G2P or G3P), are documented inFigures 2−4. Example 5: Evalua on of Xylanase Alkaline pH Speci c Ac vity in Large ScaleFermented xylanase sample is diluted with 50 mM pH 8.5 Tris-HCl bu er. A er pre-incuba ng 1 mLdiluted fermenta on sample at 85°C for 5 minutes, pre-incubated 1 mL xylan solu on (pH 8.5) isadded, and the mixture is maintained at 85°C for 30 minutes. DNS solu on (2.5 mL) is added in themixture and the mixture is then boiled for 5 minutes. A er the sample is cooled down, the sample iscentrifuged in order to separate no reacted xylan. The supernatant (360 μL) is mixed with 640 μL MilliQ water and 540 nm in the mixture is then measured using a spectrophotometer. The enzymeac vity is calculated based on xylose standard curve using DNS reac on. The results, illustra ng theimproved alkaline pH speci c ac vity of all variants in comparison to G1P are documented in FigureA y Docket No. 114095-5014-WOExample 6: Evalua on of Variant Xylanases Applica on E ect in Large ScaleThe paper whiteness assay is conducted to assess the e cacy of variant xylanases in enhancingpaper whiteness. First, 40 g of pulp sheet is broken into approximately 2 cm x 2 cm pieces and placedin a paper dissociator. A er adding 2 L of dis lled water (DW) and dissocia ng the pieces, thedissociated pulp solu on is washed with DW un l the ow-through becomes clear, maintaining aneutral pH. Subsequently, nearly 1 g of the pulp is weighed and dried overnight for furthercalcula ons. The remaining wet pulp is refrigerated un l the next day, where the dried pulp isweighed, and the required amount for the assay is calculated. The calculated wet pulp is then mixedwith MilliQ water and Tris-HCl bu er (pH 8.5, nal concentra on: 50 mM) to prepare a 10% paperpulp solu on. A er pre-incuba ng the pulp solu on at 85°C for 30 minutes, candidate xylanase isadded, and the mixture is maintained at 85°C for 2 hours with regular agita on. Following theenzyma c reac on, the pulp is washed with DW and then mixed with MilliQ water, MgSO4 ( nalconcentra on: 0.02%), EDTA ( nal concentra on: 0.03 or 0.035%), NaOH ( nal concentra on: 0.15%)and hydrogen peroxide ( nal concentra on: 0.3%) to prepare a 10% paper pulp solu on. The mixtureis maintained at 70°C for 2 hours with regular agita on. Following the chemical bleach reac on, thepulp is washed and dissociated. Wet papers are created with a paper maker and the papers are then dried with a paper dryer. The paper whiteness is assessed using a whiteness meter. The resultsdemonstrate the e ec veness of variant xylanases in enhancing paper whiteness is shown in Figure6.

Claims

1. A y Docket No. 114095-5014-WOCLAIMS1. A composi on comprising a variant xylanase as compared to SEQ ID NO:1, wherein said variantcomprises at least one amino acid subs tu on compared to SEQ ID NO: 1 at an amino acidposi on(s) selected from the group consis ng of 322, 1, 29, 67, 70, 215, 2, 3, 4, 5, 8, 22, 24, 32, 33,50, 54, 55, 56, 57, 66, 69, 77, 91, 92, 93, 99, 104, 109, 112, 116, 127, 137, 144, 164, 178, 179, 184, 188, 193, 199, 203, 204, 206, 213, 218, 241, 247, 251, 252, 256, 263, 264, 266, 267, 270, 271, 272, 292, 293, 295, 297, 317, 318, 321, 323, 325, 327 and 328, wherein said variant xylanase has at least85% iden ty to SEQ ID NO:1 and has xylanase ac vity.

2. The composi on according to claim 1, wherein said amino acid subs tu on is selected from thegroup consis ng of K322D, K322E, K322F, K322G, K322L, K322S, K322T, K322V, K322W, S1Y, S29D,S29Y, P67T, K70P, K70H, K70L, K70R, R215N, R215D, R215L, R215M, R215S, R215T, R215V, Q2P, Q2S, Q2Y, N3T, V4E, V4N, S5Q, S5Y, E8G, I22D, I22E, I22Q, I22T, N24D, N24H, N24Q, N24S, E32D, K33E, K33F, K33M, K33R, Q50A, Q50D, Q50E, Q50G, Q50N, Q50S, Q50Y, D54E, D54G, D54H, D54Y, T55A, T55D, T55K, T55L, T55N, T55P, T55R, T55S, T55V, I56T, I56V, H57E, T66A, T66P, T66R, T66V, E69D, E77R, N91Q, N91S, N91T, Q92L, Q92S, Q92W, L93N, G99D, G99R, K104R, N109E, N109F, N109T, N109W, E112A, E112C, E112D, E112F, E112G, E112I, E112K, E112L, E112N, E112P, E112R, E112S, E112T, E112V, E112W, E112Y, K116C, K116G, K116S, K127L, K127T, S137N, E144S, E144Y, K164H, S178G, S178N, I179A, I179L, I179M, I179T, I179V, A184C, A184F, A184H, A184N, A184Q, A184S, A184T, A184W, A184Y, F188A, I193T, K199R, V203I, D204H, I206V, D213T, N218K, N218Q, N218T, N218W, M241L, M241T, M241V, L247A, L247E, L247T, E251C, E251L, E251N, E251V, E252L, K256E, K256P, A263R, K264R, F266A, F266E, F266G, F266I, F266K, F266L, F266P, F266Q, F266S, F266T, F266V, F266Y, D267A, D267F, D267I, D267K, D267L, D267M, D267T, D267W, L270W, D271R, D271Y, N272H, N272P, N272T, G292A, G292D, G292E, G292N, G292S, F293T, F293V, F293W, F293Y, K295E, K295I, K295L, K295N, K295S, Y297A, Y297E, Y297Q, Y297T, K317E, K317G, K317M, K317N, K317T, K317W, E318I, E318L, E318N, E318P, E321G, K323A, K323C, K323D, K323E, K323F, K323G, K323I, K323L, K323S, K323T, K323V, E325V, R327A, R327C, R327E, R327F, R327G, R327H, R327I, R327L, R327N, R327S, R327T, R327V, R327Y, K328N and K328P.

3. A composi on according to any one of the preceding claims, wherein said variant xylanase enzymehas one or more amino acid subs tu ons at one of said posi ons, two of said posi ons, three of saidposi ons, four of said posi ons, ve of said posi ons, six of said posi ons, seven of said posi ons,eight of said posi ons, nine of said posi ons, ten of said posi ons, eleven of said posi ons, twelve ofsaid posi ons, thirteen of said posi ons, fourteen of said posi ons, een of said posi ons, sixteenA y Docket No. 114095-5014-WOof said posi ons, seventeen of said posi ons, eighteen of said posi ons, nineteen of said posi ons ortwenty of said posi ons.

4. A composi on according to any one of the preceding claims, wherein said variant xylanasecomprises a set of amino acid subs tu ons selected from the group consis ng of K322D,K322D / S1Y / S29D / P67T / K70P, K322D / S1Y / S29D / P67T / K70P / R215N, K164H, V203I / I206V / A263R, K199R / V203I / I206V / A263R, A263R, I206V / A263R, E69D / K164H / K199R / D204H, K104R / F188A / I206V, E69D / V203I / D204H / A263R, E69D / K164H / V203I / I206V, E69D / K164H / A263R, K164H / F188A / I206V, V203I, K164H / K199R / I206V / A263R, V203I / I206V, E69D / K164H / I206V, D204H / I206V / A263R, F188A / V203I / A263R, K164H / F188A / K199R / V203I, K104R / K164H, E69D / K164H / K199R / V203I / I206V / A263R, E8G, Q2S, K33R, P67T, K33E, E32D, G99D, K70R, K116S, N109W, V4E, V4N, N109T, S1Y, N3T, K70H, S5Q, Q2Y, K127T, K33M, K116G, N109E, N109F, G99R, K70L, S29D, K33F, K116C, K323L, D267I, E251N, K317M, E325V, D271Y, E318N, K323V, E252L, E318I, D267T, L247T, E251C / K323T, K295N, K322W, K317T, D271R, E251V, K295L, K295S, D267M, K323F, K256P, E321G, N272P, K322F, D267A, K322L, L247A, K328N, K323D, D267F, K323I, K295I, K323S, D267L, K323A, N272T, E318L, K323T, K322E, K317G, K323E, D267W, K256E, D267K, K322S, K317W, K322V, K323G, K322T, E251L, K317E, N272H / K328P, L247E, K323C, K317N, K322G, E318P, E32D / K33E, N3T / K70P / E251N / K295N, L247A / E251N, Q2P / E32D / L247A, E32D / E251N / D267I, K70P, E32D / K33E / K70P / L247A, Q2P / N3T / D267I, E251N / D267I, N3T / E32D / K33E / D267I / K295N / K322D, Q2P, Q2P / K70P, Q2P / N3T, E32D / K33E / E251N, E32D / L247A, Q2P / N3T / K70P, Q2P / N3T / E32D / L247A / K295I, Q2P / K70P / E251N, N3T / K33E / E251N, N3T / E32D, K33E / L247A, L247A / D267I / K295I / K322D, Q2P / K295N, N3T / K127L / D267I / K295N, E251N / K322D / K323S, K70P / E251N / D267I / K295N, N3T / E32D / K33E / K70P / K127L / D267I, K33E / K70P / D267I, N3T / E32D / L247A / D267I, K33E / K70P, Q2P / E251N / D267I / K322D, E32D / K70P / K127L / D267I, K33E / K70P / E251N / K295L / K322D, N3T / K33E / K70P / K295I / K323S, K33E / K127L / K295N, Q2P / K33E / K70P / K295I, Q2P / E32D / K70P / K322D / K323S, N3T / K70P / L247A / E251N, E32D / K33E / K295N / K322D, K70P / D213T / D267I, Q2P / K70P / D267I, K322D / F266A, R327H, K322D / Q50N, K322D / E112N, K322D / I22E, K322D / E112P, R327C, K322D / R327T, K322D / N218T, K322D / E144Y, K322D / E112S, K322D / M241T, K322D / N218Q / F266K, K322D / E112D, K322D / R327N, K322D / E112K, K322D / E112F, K322D / F266P, K322D / E112I, K322D / R327I, K322D / A184W, K322D / E112C, K322D / E112Y, R327V, K322D / T66A, K322D / A184T, K322D / E112T, K322D / Q50Y, K322D / E112W, K322D / E112R, K322D / N218W, K322D / A184C, K322D / E112G, R327G, K322D / N218K, K322D / K264R / F266P, K322D / I22T, R327F, R327Y, K322D / F266V, K322D / A184S, K322D / A184W / I193T, K322D / Q50G, K322D / T66R, K322D / Q92S, K322D / F266Q, R327S, K322D / F266Q / L270W, K322D / I179M / M241L, R327T, R327E, K322D / A184N, K322D / F266Y, K322D / E144S, K322D / T66V, K322D / E112L,A y Docket No. 114095-5014-WOK322D / A184H, K322D / A184Y, K322D / I22D, K322D / E112V, K322D / F266E, K322D / F266S, K322D / F266T, K322D / F266I, K322D / E112A, K322D / Q92W, K322D / Q92L, K322D / I22Q, K322D / T66P, K322D / F266G, K322D / F266L, K322D / M241V, R327L, R327A, K322D / A184F, K322D / Q50G / A184Q / G292E, K322D / Q92S / G292A, K322D / I22E / F266V, K322D / I22T / E112R / F266L, K322D / Q2Y / N3T / E32D / K33R / E77R / K256E, K322D / S29D / N109E / E251V, K322D / K33E / K116S / K317E, K322D / S29D / D267A / E318N, K322D / N3T / E8G / K256E, K322D / Q2S / N3T / E8G / E32D / K116S / D271R, K322D / V4N / S5Q / S29D / K295N, K322D / P67T / K70L / K127L / D267A, K322D / S29D / N109T / K127L / K295N, K322D / V4E / S5Q / S29D / K295N / E318L, K322D / S1Y / S29D / P67T / K70P / I56V / H57E / N91Q / L93N, K322D / S1Y / S29D / P67T / K70P / N24H / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / T55A / N91Q / R215N, K322D / S1Y / S29D / P67T / K70P / T55V, K322D / S1Y / S29D / P67T / K70P / D54Y / T55N / S178G / I179A / K295E / Y297Q / K317T, K322D / S1Y / S29D / P67T / K70P / Q50A / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / I56V / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / N24D / Q50G / K295E, K322D / S1Y / S29D / P67T / K70P / I56T / K295E, K322D / S1Y / S29D / P67T / K70P / D54Y / T55N / F293T, K322D / S1Y / S29D / P67T / K70P / N24H / Q50E / S137N / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / K295E, K322D / S1Y / S29D / P67T / K70P / N91Q / R215N / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / D54E / T55V / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / D54Y / T55V, K322D / S1Y / S29D / P67T / K70P / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / N24D / D54Y / T55S / G292D / F293Y / K317T, K322D / S1Y / S29D / P67T / K70P / Q50D / R215N / F293Y, K322D / S1Y / S29D / P67T / K70P / T55V / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / K317T, K322D / S1Y / S29D / P67T / K70P / D54Y / T55N / N91S / I179L / K295E, K322D / S1Y / S29D / P67T / K70P / N24H / N91Q, K322D / S1Y / S29D / P67T / K70P / N24D / D54E / T55A / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / N24D / D54Y / T55S / S178N / I179V / K295E / K317T, K322D / S1Y / S29D / P67T / K70P / I56T / L93N / G292S / F293W, K322D / S1Y / S29D / P67T / K70P / Q50G / K295E / Y297Q / K317T, K322D / S1Y / S29D / P67T / K70P / Q50S / K295E, K322D / S1Y / S29D / P67T / K70P / I56T / H57E / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / I56V / H57E / F293T, K322D / S1Y / S29D / P67T / K70P / T55S / S137N, K322D / S1Y / S29D / P67T / K70P / T55N, K322D / S1Y / S29D / P67T / K70P / D54Y / T55V / N91S / K295E / K317T, K322D / S1Y / S29D / P67T / K70P / D54E / T55R / N91Q / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / N24D / D54Y / G292N / F293W, K322D / S1Y / S29D / P67T / K70P / N24D / N91S / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / I56V, K322D / S1Y / S29D / P67T / K70P / D54G / T55P / R215N / K295E / Y297E,A y Docket No. 114095-5014-WOK322D / S1Y / S29D / P67T / K70P / N24D / D54Y / R215N / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / N24D / N91Q / L93N / G292A / F293Y, K322D / S1Y / S29D / P67T / K70P / N24D / T55N / N91Q / S137N / S178G / I179T / R215N / K317T, K322D / S1Y / S29D / P67T / K70P / N24D / I56V / G292D / F293Y, K322D / S1Y / S29D / P67T / K70P / I56V / H57E / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / N24D, K322D / S1Y / S29D / P67T / K70P / T55V / L93N, K322D / S1Y / S29D / P67T / K70P / Q50G / R215N, K322D / S1Y / S29D / P67T / K70P / N24D / I56V / I179V / R215N, K322D / S1Y / S29D / P67T / K70P / N24H, K322D / S1Y / S29D / P67T / K70P / N24D / Q50G / G292S / F293V, K322D / S1Y / S29D / P67T / K70P / G292S, K322D / S1Y / S29Y / P67T / K70P / N24D / I56T / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / T55V / K295E, K322D / S1Y / S29D / P67T / K70P / N24H / Q50A / K295E, K322D / S1Y / S29D / P67T / K70P / D54E / T55V / N91S / K295E, K322D / S1Y / S29D / P67T / K70P / T55N / G292S / F293T, K322D / S1Y / S29D / P67T / K70P / I56T / H57E / K295E / Y297Q, K322D / S1Y / S29D / P67T / K70P / I56T / H57E, K322D / S1Y / S29D / P67T / K70P / N24D / I56T / H57E, K322D / S1Y / S29D / P67T / K70P / N24H / D54Y / T55A / N91S / L93N / S137N / K295E, K322D / S1Y / S29D / P67T / K70P / D54Y / T55A / R215N / K295E / Y297E, K322D / S1Y / S29D / P67T / K70P / T55K, K322D / S1Y / S29D / P67T / K70P / N91T, K322D / S1Y / S29D / P67T / K70P / D54H, K322D / S1Y / S29D / P67T / K70P / R215M, K322D / S1Y / S29D / P67T / K70P / T55R, K322D / S1Y / S29D / P67T / K70P / R215D, K322D / S1Y / S29D / P67T / K70P / T55P, K322D / S1Y / S29D / P67T / K70P / Y297A, K322D / S1Y / S29D / P67T / K70P / N24Q, K322D / S1Y / S29D / P67T / K70P / N24S, K322D / S1Y / S29D / P67T / K70P / R215V, K322D / S1Y / S29D / P67T / K70P / R215S, K322D / S1Y / S29D / P67T / K70P / Y297T, K322D / S1Y / S29D / P67T / K70P / T55D, K322D / S1Y / S29D / P67T / K70P / T55L, K322D / S1Y / S29D / P67T / K70P / R215L, K322D / S1Y / S29D / P67T / K70P / R215T, K322D / S1Y / S29D / P67T / K70P / N91Q, K322D / S1Y / S29D / P67T / K70P / F293T / K295N, K322D / S1Y / S29D / P67T / K70P / E32D, K322D / S1Y / S29D / P67T / K70P / S5Y / E32D / S137N / G292E / K295N, K322D / S1Y / S29D / P67T / K70P / R215N / F293T, K322D / S1Y / S29D / P67T / K70L / K33E / S137N / K295N, K322D / S1Y / S29D / P67T / K70P / E32D / S137N / R215N, K322D / S1Y / S29D / P67T / K70P / E32D / K295N, K322D / S1Y / S29D / P67T / K70P / E32D / K33E / G292E / K317T, K322D / S1Y / S29D / P67T / K70P / K295N, K322D / K323S, K322D / K317T, K322D / E32D / K33E / K295N, K322D / Q50G / A184Q / G292E / K317T, K322D / E32D / K33E / K295N / K317T, K322D / E32D / K33E / K317T, K322D / K295N / K317T, K322D / E32D / K33E / P67T / K70L / K317T, K322D / P67T / K70L / K295N / K317T, K322D / E32D / K33E / Q50G / A184Q / G292E / K317T, K322D / Q50G / P67T / K70L / A184Q / G292E / K317T, K322D / E32D / K33E / Q50G / P67T / K70L / A184Q / G292E / K317T,A y Docket No. 114095-5014-WOK322D / S1Y / S29D / P67T / K70P / N24D / Q50G / K295E / , K322D / S1Y / S29D / P67T / K70P / R215N / K317T, K322D / S1Y / S29D / P67T / K70P / E32D / K33E / R215N, K322D / S1Y / S29D / P67T / K70P / E32D / K33E / R215N / K317T, K322D / Q50G / A184Q / R215N / G292E, K322D / Q50G / A184Q / R215N / G292E / K317T and K322D / S1Y / S29D / P67T / K70P / E32D / K33E / Q50G / A184Q / R215N / G292E / K317T.

5. The composi on of claim 1, wherein said variant xylanase has at least 95% sequence iden ty to anamino acid sequence selected from the group consis ng of SEQ ID NO:1, SEQ ID NO:3, SEQ ID NO:5and SEQ ID NO:

7.

6. A nucleic acid encoding the variant xylanase enzyme of any one of the preceding claims.

7. An expression vector comprising the nucleic acid of claim 6.

8. A host cell comprising the expression vector of claim 7.

9. The host cell according to claim 8, wherein the cell is a bacterium, a yeast or a fungus.

10. A method of making a variant xylanase enzyme comprising culturing the host cell of claim 8 or 9under condi ons wherein said variant xylanase enzyme is produced, and recovering said variantxylanase enzyme.

11. A method of paper biobleaching, comprising contac ng the paper with the variant xylanaseenzyme of any one of claims 1-5.

12. A method of paper biodeinking, comprising contac ng the paper with the variant xylanaseenzyme of any one of claims 1-5.

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