Synthesis and regulation of extracellular β(1−3)glucanase and protease by cytophaga sp. in batch and continuous culture

Lytic enzyme systems with the ability to break whole cells of yeast are a mixture of several enzymes and virtually all contain β(1–3)glucanases and some protease. It appears that the presence of these two enzyme activities is necessary to break the two layers of the rigid cell wall. The enzyme system of Cytophaga NCIB 9497 has a high activity towards the walls of yeast and also of bacteria. This article describes the production of this extracellular lytic enzyme system in batch and continuous culture—it was found to be inducible. The synthesis and regulation of the two main constituent enzymes, β(1–3)glucanase and protease, have been investigated. The synthesis of β(1–3)glucanase is regulated by bothinduction (by an unknown inducer) and catabolite repression. Highβ(1–3)glucanase activities were obtained in continuous culture at low dilution rates over a narrow range (0.05–0.10 h−1), and there is evidence of the presence of more than one glucanase enzyme. Proteolytic activity appears subject to catabolite repression and made up of the activities of more than one protease enzyme. Productivity and enzyme concentration were increased several fold in continuous culture when compared to batch culture.