CHARACTERIZATION OF KINETIC-PARAMETERS AND METABOLIC TRANSITION OF CORYNEBACTERIUM-GLUTAMICUM ON L-LYSINE PRODUCTION IN CONTINUOUS-CULTURE

Kinetic parameters and physiological states of Corynebacterium glutami cum at the growing and L-lysine-overproducing phase were characterised in continuous culture on threonine-limited complex and minimal media. High L-lysine productivity occurred at dilution rates ranging from 0. 1h(-1) to 0.3h(-1) on threonine-limited complex medium, and at dilutio n rates ranging from 0.1h(-1) to 0.15h(-1) in minimal medium. L-Lysine yields of 0.25 g/g (0.31 g/g as L-lysine hydrochloride) in complex me dium, and of 0.17 g/g (0.21 g/g as L-lysine hydrochloride) in minimal medium, corresponding respectively to intrinsic yields of 0.533 g/g an d 0.572 g/g were obtained. These intrinsic yield factors are dosed to the theoretical ones (0.608 g/g, 0.75 mol/mol). Intrinsic biomass yiel ds were calculated as 0.658 g/g in complex medium and 0.283 g/g in min imal medium. CO2 production has been clearly related to L-lysine produ ction. According to our results on specific uptake rates and specific productivities in complex medium, metabolic rearrangement should occur during the transition from the growing phase to the L-lysine-overprod ucing phase. This phenomenon was further investigated.