关键词: 虫花棒束孢, 蝙蝠蛾拟青霉, 乙酸乙酯粗提物, 抗氧化活性, 抗菌活性, 菌株差异

Abstract: Isaria farinosa is a widely distributed entomopathogenic fungus in soil-dwelling insects. It has been extensively studied and applied in biological control of insects, and also attracted researchers′ attention for its pharmacological effects and bioactive metabolites. In this study, seven strains of I. farinosa from different origins were selected based on morphological and molecular identification to reveal the variation among strains. Antioxidant effects and antimicrobial activities were tested by crude ethyl acetate extracts from the strains cultivated on rice medium. The results showed that the strains displayed significant variations in the bioactivities tested under the same conditions and strain 2142 had the best performance. In particular, the crude extract (200 mg/mL) from strain 2142 had the similar effect with Bacillus cereus to that of ampicillin sodium (80 μg/mL) used as the positive control in the antimicrobial experiment. Further investigation on the strain was required to explore its potentials. There are broad prospects for the application of I. farinosa in health foods and pharmaceutical product, but the caution should be taken in the selection of strains for such purposes. It is important to evaluate the safety of any strain before its application in the area associated with human health.

Key words: Isaria farinosa, Paecilomyces hepiali, crude ethyl acetate extracts, antioxidant effects, antimicrobial activity, strain variation