Phomopsis sp. as an endophyte of Turnera subulata L.: Isolation, identification and antimicrobial and antioxidant activity of their extracts

摘要

Turnera subulata L. is a plant that belongs to the Turneraceae family and is popularly known in Brazil as “Chanana”; it is used as an alternative medicine. Among all microorganisms, fungi are mostly associated with plants. The aim of this study is to isolate, identify and evaluate the antifungal and antioxidant activity of extracts of Phomopsis sp. isolated from T. subulata. From the leaf fragment obtained from T. subulata, the filamentous endophytic fungus Phomopsis sp was isolated. The fungal isolate had a higher growth in potato dextrose agar (PDA) and potato sucrose agar (PSA) culture medium, as well as in the presence of light. In the antagonism test of the endophytic Phomopsis sp. against human pathogens, there was inhibition zone against Escherichia coli, Staphylococcus aureus, Candida albicans, C. tropicalis and C. glabrata. Concerning the antioxidant activity, it was observed that the chloroform extract was more effective than hexane. On the other hand, all the extracts from the mycelium of Phomopsis sp. and its ethyl acetate extract from the cultured filtrate had low antimicrobial activity against strains of E. coli, S. aureus, C. albicans, C. tropicalis and C. glabrata. Therefore it was concluded that Phomopsis sp. may act as an endophyte of T. subulata. Extracts from Phomopsis sp. promoted inhibition zone of growth when tested against human pathogen. Its hexanic and chloroform extracts showed lower antioxidant activity.