Conversion of cellulose to glucose with cellulase of Trichoderma viride ITCC‐1433

Trichoderma viride ITCC‐1433 secretes a cellulase complex that is rich in β‐glucosidase and therefore well suited for the saccharification of cellulosic materials. The cellulase was investigated with respect to optimum conditions of reaction and enzyme stability. Avicelase, CMCase, and β‐glucosidase differed considerably in their physicochemical properties. At temperatures above 50°C, β‐glucosidase is not very stable. Therefore, as a compromise the conditions of hydrolysis were chosen to be 50°C and pH 4.5. With the crude culture filtrate of T. viride ITCC‐1433 a nearly pure glucose solution of 4% is reached from a 10% cellulose suspension. Wood pulp and newsprint are hydrolyzed to a much smaller extent. With an enzyme concentrate up to 8% glucose accumulated in the reaction fluid within 48 hr. At this time the glucose‐cellobiose ratio was 75:1. Glucose was demonstrated to be the most potent inhibitor of total hydrolysis. The addition of glucose to the enzyme‐substrate solution at zero time completely stopped its own formation and cellobiose and reducing groups (oligosaccharides) accumulated. By removing glucose through an ultrafilter device about 90% saccharification of cellulose to glucose was achieved in 48 hr without any accumulation of cellobiose.