Enzymes of Aspergillus Oryzae III. The Sequence of Appearance and Some Properties of the Enzymes Liberated During Growth

Abstract

When a strain of the mould Aspergillus oryzae is grown in surface culture on a protein-free sucrose-tartrate medium, enzymes are released into the culture medium in the following order first, the carbo-hydrases sucrase and amylase, together with phosphatase, second, the proteases and esterases, and third, catalase. Their liberation is accompanied by appearance of protein N in medium and loss in wt. of mycelium. Evidence is presented for presence of at least 2 proteases in addition to glycylglycine dipeptidase[long dash]one reduces viscosity of gelatin very rapidly and is believed to act preferentially on high-molecular-wt. fractions of gelatin (the "viscometric protease") whereas the other degrades lower molecular components of the gelatin more readily (the "gravimetric protease"). The pH activity curves for sucrase and amylase also indicate presence of more than one component. Inactivation of the various enzymes present during incubation at 40C and at different pH values has been followed.