The present invention provides nucleotide sequences of Macrophomina phaseolina (“M. phaseolina”) that encodes proteins/enzymes with cellulolytic activity, including a cellulase activity, a endoglucanase, a cellobiohydrolase, a β-glucosidase, a a-glucosidase, a xylanase, a mannanse, a β-xylosidase, a a-xylosidase, a galactosidase, an arabinofuranosidase, a a-fucosidases, a β-galactanase, an unsaturated β-glucuronyl hydrolase and/or oligomerase activity. Vectors, expression constructs and host cells comprising and/or consisting of the nucleotide sequences of the enzyme genes are also provided. The invention further provides methods for producing the enzymes and methods for modifying the enzymes in order to improve their desirable characteristics. The enzymes of the invention can be used in a variety of, but not limited to, pharmaceutical, agricultural, food and feed processing, biofuel, energy efficiency and industrial contexts. These enzymes are also useful for complete hydrolysis of lignocellulosic biomass into simple sugar that can then be fermented to liquid fuels and chemical feedstocks.

A xylosidase having improved enzymatic activity is disclosed. The amino acid sequence of the xylosidase is a modified amino acid sequence of SEQ ID NO: 2, wherein the modification is a substitution of phenylalanine at position 35 with glutamate, and/or a substitution of glutamine at position 41 with histidine.

A xylosidase having improved enzymatic activity is disclosed. The amino acid sequence of the xylosidase is a modified amino acid sequence of SEQ ID NO: 2, wherein the modification is a substitution of phenylalanine at position 35 with glutamate, and/or a substitution of glutamine at position 41 with histidine.