Cellulolytic enzyme compositions and uses thereof

Abstract

The present invention relates enzyme composition comprising a cellulolytic preparation and an acetylxylan esterase (AXE); and the used of cellulolytic enzyme compositions for hydrolyzing acetylated cellulosic material. Finally the invention also relates to processes of producing fermentation products from acetylated cellulosic materials using a cellulolytic enzyme composition of the invention.

1 . A method of hydrolyzing acetylated acid-pretreated cellulosic material, comprising subjecting the acetylated cellulosic material to a cellulolytic preparation and an acetylxylan esterase (AXE), wherein the acetylxylan esterase (AXE) is derived from a strain of  Thielavia terrestris  and has at least 80% sequence identity to SEQ ID NO: 1 or is derived from a strain of  Humicola insolens  and has at least 80% sequence identity to SEQ ID NO: 3. 
     
     
         2 . The method of  claim 1 , wherein the acetylated acid-pretreated cellulosic material is thermomechanically pulped plant material. 
     
     
         3 . The method of  claim 2 , wherein the thermomechanically pulped plant material is acetylated corn stover pulp. 
     
     
         4 . The method of  claim 1 , wherein the acetylated acid-pretreated cellulosic material has a degree of acetylation of the cellulosic material of about 5-10%. 
     
     
         5 . The method of  claim 1 , wherein the cellulolytic preparation is a  Trichoderma reesei  cellulolytic preparation, further comprising  Penicillium emersonii  GH61A polypeptide having cellulolytic enhancing activity,  Aspergillus fumigatus  beta-glucosidase variant and  Aspergillus fumigatus  beta-xylosidase. 
     
     
         6 . The method of  claim 1 , wherein the ratio between cellulolytic preparation and acetylxylan esterase (AXE) is in the range in a ratio of between 500:1 and 1:1, between 50:1 and 2:1, or about 4:1. 
     
     
         7 . The method of  claim 1 , wherein the acetylxylan esterase has at least 85%, such as at least 90%, preferably 95%, such as at least 96%, such as 97%, such as at least 98%, such as at least 99% identity to SEQ ID NO: 1 herein. 
     
     
         8 . The method of  claim 1 , wherein the acetylxylan esterase has at least 85%, such as at least 90%, preferably 95%, such as at least 96%, such as 97%, such as at least 98%, such as at least 99% identity to SEQ ID NO: 3 herein. 
     
     
         9 . A process of producing a fermentation product from acetylated acid-pretreated cellulosic material, comprising:
 (a) hydrolyzing said acetylated acid-pretreated cellulosic material by subjecting the material to an enzyme composition comprising a cellulolytic preparation and an acetylxylan esterase (AXE), wherein the acetylxylan esterase (AXE) is derived from a strain of  Thielavia terrestris  and has at least 80% sequence identity to SEQ ID NO: 1 or is derived from a strain of  Humicola insolens  and has at least 80% sequence identity to SEQ ID NO: 3;   (b) fermenting using a fermenting organism; and   (c) optionally recovering the fermentation product.   
     
     
         10 . The process of  claim 9 , wherein the fermentation product is ethanol. 
     
     
         11 . The method of  claim 9 , wherein the acetylated acid-pretreated cellulosic material is thermomechanically pulped plant material. 
     
     
         12 . The method of  claim 11 , wherein the thermomechanically pulped plant material is acetylated corn stover pulp. 
     
     
         13 . The method of  claim 9 , wherein the acetylated acid-pretreated cellulosic material has a degree of acetylation of the cellulosic material of about 5-10%. 
     
     
         14 . The method of  claim 9 , wherein the acetylxylan esterase has at least 85%, such as at least 90%, preferably 95%, such as at least 96%, such as 97%, such as at least 98%, such as at least 99% identity to SEQ ID NO: 1 herein. 
     
     
         15 . The method of  claim 9 , wherein the acetylxylan esterase has at least 85%, such as at least 90%, preferably 95%, such as at least 96%, such as 97%, such as at least 98%, such as at least 99% identity to SEQ ID NO: 3 herein.