EFFECT OF AGITATION ON GROWTH AND ENZYME-PRODUCTION OF TRICHODERMA-REESEI IN BATCH FERMENTATION

Growth, enzyme-producing activity and respiratory properties of Tricho derma reesei QM 9414 were examined under various agitation intensities . Two substrates were compared: lactose and Avicel. Pellet formation o ccurred at all agitation intensities for both substrates. Oxygen depen dence at the lower agitation rate varied with the substrate type. With lactose as the carbon source, linear growth was observed, despite a r egulation of the dissolved oxygen concentration at 30% saturation. The enzyme production was strongly affected by the agitation. At the high er agitation rates the enzyme production dropped. With Avicel as the c arbon source, the production of enzymes surged as soon as the growth w as limited by the hydrolysis of Avicel. Growth on Avicel, in the condi tions we used, was limited by Avicel hydrolysis. Cubic growth was obse rved when lactose was the carbon source. A new derivation for a model of the observed cubic growth is proposed and is used to correlate grow th, CO2 production and oxygen consumption in a consistent way, impossi ble with exponential growth models.