Spectrum of Biological Activity of Extracts from Cultures of Distinct Isolates of Bipolaris sorokiniana Produced on Different Media

Abstract—Bipolaris sorokiniana is circumglobally widespread root and leaf pathogen of cereals and grasses. It can grow both endo- and epiphytically and also survive in the soil. The chemical mechanisms of such good persistence of the fungus are poorly studied. This study assays the biological (phytotoxic, antimicrobial, insecticidal, and cytotoxic) activity of extracts from cultures of four B. sorokiniana of distinct geographical origin produced on three different media. The composition of media and, to lesser extent, origin of the isolate affected the yield of extractive matter, spectrum, and level of biological activity of extracts. Extracts from liquid culture mycelium demonstrated relatively high insecticidal activity to wheat aphid and galleria, while extracts from solid cultures were highly cytotoxic to the Sf9 cell line. Phytotoxic activity was the most pronounced in extracts from culture liquids. No correlation was found between phytotoxic and insecticidal or cytotoxic activity of extracts indicating possible production of insecticidal metabolites by B. sorokiniana isolates. The revealed insecticidal properties of the fungal metabolites were able to explain its high competition activity for the plant substrate and broaden the biotechnological potential B. sorokiniana of as a producer of bioactive compounds.