Production of Bacteriolytic Enzymes and Degradation of Bacteria by Filamentous Fungi

Of 33 filamentous fungi, representing five taxonomic subdivisions, 31 were able to grow on heat-killed Bacillus subtilis cells as sole C, N and P source. Two types of decomposition were observed: cytolysis, in which the bacterial cytoplasm was rapidly degraded, leaving apparently empty cell walls, and bacteriolysis, in which the entire bacterial cell gradually disintegrated. Supernatants of cultures in which the latter type of attack occurred contained enzymes capable of dissolving bacterial cell walls. Most of these enzymes were glycosidases with pH optima of 2.0-3.9. Two were peptidases and/or amidases with pH optima of 7.8-8.3.