TRANSGLYCOSYLATION OF EXTRACELLULAR BETA-GLUCOSIDASE OF TRICHODERMA-PSEUDOKONINGII S38 AND ITS FUNCTION IN REGULATION OF CELLULASE BIOSYNTHESIS

Two beta-glucosidase (beta G) components, beta G1 and beta G2, purifie d from extracellular culture filtrate of Trichoderma pseudokoningii S3 8 by chromatography techniques, showed transglycosylation activity, th e character of which was previously believed to belong to the membrane -bound beta G. beta G1 also hydrolyzed cellobiose (and other beta-link ed disaccharides) to produce glucose, and could hydrolyze p-nitropheny l-beta-D-glucoside (PNPG). However, the activity of hydrolysis of disa ccharides and PNPG of beta G2 was lower than that of beta G1, but it h ad higher transglycosylation activity, showing different substrate spe cificities. The transcosylation products originating from cellobiose b y beta Gs, such as all of the other beta-linked disaccharides and even cellotriose, were determined by HPLC. Among them, gentiobiose was bel ieved to be the most effective inducer of cellulose biosynthesis in th is strains. The induction ability of a certain disaccharide had a rela tionship with its amount in the traction mixture which was controlled by the dual activities of beta G, hydrolysis and transglycosylation.