REGULATION OF BETA-GLUCOSIDASE BIOSYNTHESIS IN ASPERGILLUS-NIDULANS

beta-Glucosidase in Aspergillus nidulans was found to be both intracel lular and extracellular. The intracellular beta-glucosidase was synthe sized after the exhaustion of carbon source in the medium. The extrace llular enzyme appeared with autolysis of the mycelium. Biosynthesis of beta-glucosidase was not induced by various carbohydrates but repress ed to varying extents in the presence of glucose, glycerol, and 2-deox yglucose. This repression was not relieved by addition of cAMP. The re pression was relieved much more by mutations in the creA gene than by one in the creC gene. Thus, beta-glucosidase synthesis in A. nidulans is subject to carbon catabolite repression.