Isolation and screening of endophytic fungi from three plants used in traditional medicine in Nigeria for antimicrobial activity

Abstract

Background: Endophytes represent a promising source of biologically active metabolites for pharmaceutical and agricultural applications. Objective: This study was aimed to investigate the endophytic fungi diversity and the antimicrobial potential of three popular medicinal plants (Alstonia boonei‐Ahun, Enantia chlorantha‐Awopa and Kigelia africana‐Pandoro) that have ethnobotanical history in Nigeria. Materials and Methods: The stem barks were used for isolation of endophytic fungi and fermented, and the cell free fermentation broths were subjected to antimicrobial screening against six human pathogens; Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and Candida albicans by using standard agar well diffusion method. Results: A total of ten endophytic fungi were isolated from the stem bark of the plants. Seven of these fungi were identified,which include; Aspergillus niger, Macrophomina spp., Trichoderma spp. and four different Penicillium species, while three of the isolated endophytes remained unknown. Furthermore, nine of the isolated endophytes showed potential antimicrobial activity against at least one of the six tested pathogens. Conclusion: This study shows that endophytic fungi inhabiting the inner tissue of medicinal plants studied may be the source of the curative properties of the plants. Key words: Agar well diffusion, antimicrobial activity, endophytes, medicinal plant