PRODUCTION OF CELLULASE ENZYME FROM LACTOSE IN BATCH AND CONTINUOUS CULTURES BY A PARTIALLY CONSTITUTIVE STRAIN OF TRICHODERMA-REESEI

The present studies concern the production of cellulases, in batch and in continuous cultures, using a mutant strain T. reesei C-5 growing o n soluble carbon substrate, lactose. The maximum specific growth rate (mu(max)) and saturation constant (K(s)) in continuous culture at 2%fe ed lactose were estimated to be 0.066 h-1 and 1.17 g l-1, respectively . The corresponding values in batch culture on 4% lactose were estimat ed to be 0.067 h-1 and 1.36 g l-1, respectively, and the corresponding overall growth yield factor (Y0) was found to be 0.63 g cell g lactos e-1 (in 60 h). The volumetric enzyme productivity (E), and specific en zyme productivity (v) in continuous culture with 2% feed lactose were found to be 51.52 IU l-1 h-1 and 4.58 IU mg cell-1 h-1, respectively, and the corresponding values with 4% feed lactose were estimated to be 56.02 IU l-1 h-1 and 2.68 IU l-1 h-1, respectively. From the pulse re sponse of 0.2% glucose, partial catabolic repression was noticed. The addition of 0.2% cellulose produced an inducing effect for enzyme synt hesis. It was noticed that T. reesei C-5 is a highly derepressed mutan t strain capable of synthesizing active cellulases on soluble sugar la ctose.