Production and Antifungal Activity of Secondary Metabolites of Trichoderma virens

Toxins namely gliotoxin, dimethyl gliotoxin, viridin and viridiol were isolated from chloroform extract of 15 days old culture filtrate of a strain of Trichoderma virens (ITC-4777) grown in potato dextrose broth. Their structures were confirmed by 1H-NMR, and mass spectroscopy. Gliotoxin was found to be active against Rhizoctonia bataticola (ED50 0.03 µg ml-1), Macrophomina phaseolina (ED50 1.76 µg ml”1), Pythium deharyanum (ED50 29.38 µg ml1), Pythium aphanidermatum (ED50 12.02 µg ml-1), Sclerotium rolfsii (ED50 2.11 µg ml-1), Rhizoctonia solani (ED50 3.18 µg ml−1). Decrease in production of gliotoxin was observed with increase in days of incubation of culture of T. virens. Maximum production of gliotoxin was observed in the 7 day old culture filtrate.