
Full text loading...
SUMMARY: Several species of soil actinomycetes arrested the growth of fungi by antibiotic secretions on agar media containing 10 g. glucose/1. On media of lower glucose concentration, the fungi continued to grow in the presence of the actinomycetes, but there was evidence that traces of antibiotic substances were still being formed. In sand moistened with liquid medium containing glucose, S. albidoflavus limited early growth of Fusarium culmorum by antibiotic action and also attacked preformed fungus mycelium directly. The effectiveness of these antagonistic mechanisms was decreased when the glucose concentration was lowered. The fungus and the actinomycete grew together on a variety of natural organic materials, but only when dried grass was used did the actinomycete arrest growth of the fungus at a distance.