PRODUCTION OF EXTRACELLULAR ENZYMES BY IMMOBILIZED TRICHODERMA-REESEIIN SHAKE FLASK CULTURES

Polyurethane foam and nylon-web carriers were compared for simultaneou s production of endo-1, 4-beta-glucanase and xylanase by immobilized T richoderma reesei on a medium based on lactose (27 g/l), cellulose (3 g/l) and sorbose (0.3 g/l). Nylon sheet with 1.2 cm(2) carrier surface /ml medium was superior to the others, and it was selected for further studies. The carbon source had a marked effect on enzyme production b y the immobilized fungus. With pure cellulose (10 g/l) as substrate, t he maximum endoglucanase activity was 690 nkat/ml and xylanase activit y 4800 nkat/ml. Supplementation with 0.5 g/l of sorbose resulted in an increase in both endoglucanase and xylanase activities in all media s tudied. A more detailed study on the effect of sorbose on a lactose(7 g/l)- and cellulose(3 g/l)-based medium revealed a clear optimum sorbo se concentration of 1.5 g/l, with a maximum endoglucanase activity of 660 nkat/ml, xylanase activity of 3670 nkat/ml, and filter-paper activ ity (overall cellulolytic activity) of 2.0 filter-paper units/ml. Howe ver, the addition of 1.5 g/l sorbose to the pure-cellulose(10 g/l)-bas ed medium resulted in a slight decrease in the enzyme production.