Abstract: A GH10 xylanase variant is disclosed herein. This GH10 xylanase variant has increased thermostability compared with a parent GH10 xylanase enzyme comprising at least 90% sequence identity with the amino acid sequence of SEQ ID No. 1 wherein the variant has been modified at two or more of the following positions 7, 33, 79, 217 and 298 corresponding to the amino acid numbering of SEQ ID No. 1.

Abstract: The present invention relates to an isolated polypeptide having xylanase activity, selected from the group consisting of: a) a polypeptide comprising an amino acid sequence having at least 87% identity with SEQ ID NO: 1; b) a polypeptide encoded by a polynucleotide having at least 87% identity with SEQ ID NO:2; or c) a fragment of a polypeptide of a) or b) which fragment has xylanase activity.

Abstract: The present inventions relates to a modified GH10 xylanase enzyme or a fragment thereof having xylanase activity wherein said modified GH10 xylanase or fragment thereof has increased thermostability compared with a parent GH10 xylanase enzyme, the parent GH10 xylanase having been modified at, at least, two of the following positions 7, 33, 79, 217 and 298, wherein the numbering is based on the amino acid numbering of FveXyn4 (SEQ ID No. 1). In particular, the modified xylanase enzyme according to the present invention has the following modifications: N7D; T33V; K79Y, V, F, I, L or M (preferably K79Y, F or V, more preferably Y); A217Q, E, P, D or M (preferably A217Q, E or P, more preferably Q); and T298Y, F or W (preferably Y or F, more preferably Y).