Location and biosynthetic regulation of endo-1,4-beta-glucanase in Aspergillus nidulans.

The location and biosynthetic regulation of endo-1,4-beta-glucanase were studied in Aspergillus nidulans. The enzyme was found to be extracellular, but low intracellular activity was also detected at the beginning of enzyme induction. The synthesis of the enzyme was regulated by carbon catabolite repression as well as specific induction. beta-1,4-Linked carbohydrates, such as carboxymethylcellulose, cellobiose and lactose, induced the enzyme synthesis, while 2-deoxyglucose and readily metabolizable substrates, such as glucose and glycerol, repressed it. Carbon catabolite repression could not be overcome by cAMP. Actinomycin D and cycloheximide completely inhibited the enzyme synthesis, which indicated the novo synthesis.