| Abstract |
This examined some conditions for the induction of β-D-galactosidase synthesis in Candida kefyr CBS 834. The optimal pH, temperature, and inoculum size either for growth or β-D-galactosidase synthesis were 5.5, 30℃ and above 0.2 at A610nm, respectively. Enzyme activity began to increase at 2h after the addition of inducer, and continued to increase linearly up to 2~3h before reaching stationary phase, and thereafter its activity was decreased. β-D-galactosidase was induced either by lactose or galactose but not either by glucose or ethanol. The greater activity of β-D-galactosidase on galactose than on lactose indicated that the former might be natural inducer for β-D-galactosidase synthesis. The rate of its induction as a function of lactose concentration showed that enzyme activity increased linearly above 4mM, while it was very low below that. Glucose represed the induction of β-D-galactosidase, and the period of adaptation to inducer from other carbon sources was relatively short. |
