Studies in the growth requirements of Indian fungi

Abstract

Twenty-six isolates of fungi from different host plants were tested for vitamin requirements. Eleven isolates (including several morphologically similar isolates of Pellicularia koleroga) were heterotrophic to thiamine, but their capacity to synthesize this vitamin was not completely lost as they do so from a mixture of thiazole and pyrimidine or from pyrimidine alone. Piricularia oryzae, however, was unable to do this in young cultures, but with advancing age utilized an equimolar mixture of thiazole and pyrimidine or pyrimidine alone. Some isolates were also tested for growth response with riboflavin, biotin and pantothenic acid. A strain of Aspergillus niger isolated from Indian soil was more sensitive in detecting traces of copper and molybdenum than the standard A. niger 'M' strain used for bio-assay of heavy metals.