GLUCANOLYTIC ENZYME PRODUCTION BY SCHIZOPHYLLUM COMMUNE FR DURING MYCOPARASITISM

摘要

Schizophyllum commune S-25 was able to attack 16 out of 50 fungi tested, representing oomycetes, zygomycetes and hyphomycetes, which are either saprophytic, soilborne or foliar plant pathogens. In dual culture agar plates consisting of S. commune and its host Rhizotonia solani, the production of extracellular endo-beta-1,3(4)-glucanase was markedly enhanced, whereas chitinase, N-acetylglucosaminidase and glucosidase were not or barely detected. Coincidentally, the major constituents of the crude enzyme from dual culture broth was endo-beta-1,3(4)-glucanase. Treatment of the young hyphae of R. solani by these crude enzyme preparations led to the release of protoplasts. The specific activity of the endo-beta-1,3(4)-glucanase from crude preparations was increased 240 times by DEAE-Sephadex ion exchange chromatography, Sephadex G-100 gel filtration and isoelectric focusing. The purified endo-beta-1,3(4)-glucanase was capable of hydrolysing purified cell walls of R. solani. It is suggested that endo-beta-1,3(4)-glucanase in cooperation with trace amounts of certain wall-lytic enzymes, such as cellulase produced by S. commune may play a crucial role in host-parasite interactions.