Influence of L-Sorbose on Growth and Enzyme Synthesis of Trichoderma reesei C-5

Abstract

SUMMARY: The effects of L-sorbose on the growth and biosynthesis of cellulases and other polysaccharide-degrading enzymes of Trichoderma reesei C-5 were studied. The specific growth rate and yield of this strain in batch culture were reduced by 23% and 46% respectively on addition of 1% (w/v) sorbose to Vogel's medium containing 1% (w/v) glucose. The specific consumption rate of both sorbose and glucose decreased in the presence of the other sugar at 1% (w/v) concentration. The addition of sorbose (1-5%) to cultures grown in 1% glucose resulted in enhanced activities of all cellulase enzymes, and particularly endoglucanase activity, which increased sevenfold in the presence of 5% sorbose. There was no significant effect on the activities of β-glucosidase, acid phosphatase and amylase. While the increased enzyme activities seemed to be correlated with a decreased rate of glucose consumption, a direct effect on some extracellular enzymes could not be ruled out.