Abstract: Compositions and methods are provided for treating lignocellulosic material with a xylanase enzyme having xylanase activity. The enzyme is stable and active at increased pHs and temperatures. The present invention therefore provides methods for hydrolyzing lignocellulosic material, especially cellulose and hemicellulose, which are major components of the cell wall of non-woody and woody plants. The methods for hydrolyzing cellulose and hemicellulose can be used on any plant, wood or wood product, wood waste, paper pulp, paper product or paper waste or byproduct.