Altering enzyme balance through fermentation conditions

Abstract

This present disclosure relates to methods for improved production of proteins from a cell culture, particularly to culture components and conditions that can preferentially increase the expression of proteins produced from genes under the control of xylanase gene promoter sequences. The improved methods can be used for the production of enzyme compositions with enhanced xylanase and hem icellulolytic activity.

1 - 24 . (canceled) 
     
     
         25 . A mixed saccharide composition produced by:
 a) mixing a glucose solution with a transglycosylating enzyme to give an enzyme-glucose mixture;   b) incubating the enzyme-glucose mixture at an elevated temperature of 50° C. to 75° C. for a time sufficient to give a processed glucose mixture comprising at least one oligosaccharide;   c) mixing the processed glucose mixture with a pentose to yield the mixed saccharide composition,   wherein the transglycosylating enzyme is capable of processing the glucose in the glucose mixture into at least one oligosaccharide, which, when mixed with the pentose of c), is capable of enhancing hemicellulase production without significantly reducing cellulase production by filamentous fungi.   
     
     
         26 . An enzyme composition produced by:
 a) mixing a glucose solution with a transglycosylating enzyme to give an enzyme-glucose mixture;   b) incubating the enzyme-glucose mixture at an elevated temperature of 50° C. to 75° C. for a time sufficient to give a processed glucose mixture comprising at least one oligosaccharide;   c) mixing the processed glucose mixture with a pentose to yield a mixed saccharide composition;   d) exposing a filamentous fungi to the mixed saccharide composition under conditions conducive to protein expression to generate the enzyme composition,   wherein the transglycosylating enzyme is capable of processing the glucose in the glucose mixture into at least one oligosaccharide, which, when mixed with the pentose of c), is capable of enhancing hemicellulase production without significantly reducing cellulase production by filamentous fungi.   
     
     
         27 . A method of degrading a biomass comprising contacting the biomass substrate with an enzyme composition of  claim 26 . 
     
     
         28 . An enzyme composition comprising, made by, or obtainable by mixing:
 (a) one or more xylanase enzyme(s) wherein at least one of said one or more xylanase enzyme(s) is a XYN2, or a XYN3; and   (b) one or more cellulase enzyme(s) wherein at least one of said one or more more cellulase enzyme(s) is a CBH1, a CBH2 or a BGL1; wherein said enzyme composition comprises a ratio of a about 0.5 to about 1.0 xylanases to cellulases (wt/wt) or a ratio of about 0.05 to about 1.5 xylanase to CBH1 (wt/wt).   
     
     
         29 . The enzyme composition of  claim 28 , wherein said enzyme composition comprises a ratio of about 0.1 to about 1.0 XYN2 to CBH1 (wt/wt). 
     
     
         30 . The enzyme composition of  claim 28 , wherein said enzyme composition comprises a ratio of about 0.05 to about 0.5 XYN3 to CBH1 (wt/wt). 
     
     
         31 . The enzyme composition of  claim 28 , wherein said enzyme composition comprises a ratio of about 0.5 to about 1.0 xylanases to cellulases (wt/wt). 
     
     
         32 . The enzyme composition of  claim 28 , wherein said xylanases comprises XYN2 and XYN3. 
     
     
         33 . The enzyme composition of  claim 28 , wherein said cellulases comprises CBH1, CBH2 and BGL1. 
     
     
         34 . The method of  claim 27 , wherein the biomass substrate is selected from trees, shrubs, grasses, wheat, wheatstraw, sugar cane bagasse, corn, corn husks, corn kernel, products and by-products from milling of grains, municipal solid waste, waste paper, yard waste, wood, wood pulp, papermaking sludge, paper pulp waste streams, particle board, corn stover, corn fiber, rice, woody and herbaceous plants, fruit pulp, vegetable pulp, pumice, distillers grain, grasses, rice hulls, cotton, jute, hemp, flax, bamboo, sisal, abaca, straw, corn cob, leaves, coconut hair, algae, switchgrass, giant reeds or mixtures thereof. 
     
     
         35 . The method of  claim 34 , wherein the biomass substrate is subject to pretreatment before contacting the enzyme composition.