Conversion of viridin to viridiol by viridin-producing fungi.

The fungistatic compound viridin, produced by the fungus Gliocladium virens, was found to be irreversibly reduced to the phytotoxin viridiol in liquid culture. Conversion occurred only in the presence of viridin-producing fungi and was subsequent to viridin production. Radiolabelled viridin was rapidly taken up by the mycelium of G. virens and reduced to radiolabelled viridiol, while labelled viridiol was not taken up to any significant extent by the mycelium. Reduction of viridin to viridiol was independent of culture pH, carbon source, and nitrogen source or quantity. A simple production system consisting of peat moss amended with dextrose and calcium nitrate and inoculated with G. virens supported production of 86 micrograms viridiol/g peat. This production system, when applied to soil, may have value as a herbicide.