Antimicrobial, antioxidant activity and phytochemical analysis of an endophytic species of Nigrospora isolated from living fossil Ginkgo biloba
Current Research in Environmental & Applied Mycology
Nigropsora sp. was isolated as an endophyte from a medicinal plant, Ginkgo biloba. Ethyl acetate extract of the fungus was evaluated for antimicrobial and free radical scavenging (DPPH) activity. Ethyl acetate extract was effective against Escherichia coli (R-2046), Klebsiella sp. (R-2434), Staphylococcus aureus (ATCC 6538), Candida albicans (NCIM 3471) and Geotrichum sp. (NFCCI-2521) while it did not show activity against Saccharomyces cerevisiae (NFCCI-1248), Nodulisporium sp. (NFCCI-2264)
... sp. (NFCCI-2264) and Syncephalastrum sp. (NFCCI-2269). The minimum inhibitory concentration (MIC) of ethyl acetate extract evaluated by tube broth dilution method was recoerded as 2.5mg/ml against all test organisms while by agar dilution method it was recorded as 1.25mg/ml against E. coli, 0.15625mg/ml against S. aureus and 0.3125mg/ml against Klebsiella sp. and C. albicans. The TLC-bioautography assay, used to screen the plant extracts for antimicrobial activity and localization of the active compounds indicated the presence of a number of inhibitory compounds with activity against tested microorganisms. Phytochemical analysis revealed the presence phenolic compounds and anthraquinones. Nigrospora sp. was also examined for in vitro antioxidant activity by DPPH radical scavenging assay. The ethyl acetate extract of the fungus showed potent antioxidant activity with IC 50 value of 9.28µg/ml compared to the IC 50 value of standard ascorbic acid, 1.74μg/ml.