Antifungal activity of extracellular metabolites produced by Sporothrix flocculosa

The antifungal properties of extracellular compounds produced by the epiphytic fungus Sporothrix flocculosa were bioassayed against phytopathogenie fungi on the basis of inhibition of spore germination, and mycelial growth and induction of cellular leakage. Following incubation in stationary culture, S. flocculosa released antifungal metabolites into the culture medium which were extractable with methylene chloride. When separated by thin layer chromatography, extracted metabolites yielded a compound(s) at Rf0.65 which inhibited development of Cladosporium cucumerinum and several other phytopathogenic fungi. Treatment of Botrytis cinerea and Fusarium oxysporum f.sp. radicis‐lycopersici (FORL) with the same compound(s) greatly reduced spore germination and biomass growth of both fungi. Additionally, both B. cinerea and FORL leaked electrolytes and proteins when grown in presence of the metabolites. Observations under electron microscopy revealed that FORL reacted to the presence of S. flocculosa metabolite...