Antimicrobial potentials of idiolites of endophytic fungi isolated from the leaves of Dacryodes edulis

Abstract

The growing levels of antimicrobial resistance have triggered interest in the search for alternative compounds to wage the war against it. Plants have been shown to harbor endophytic fungi that produce bioactive idiolites, which have potential lead compounds in the development of new drugs. This study evaluated the antimicrobial activity of endophytic fungi isolated from leaves of Dacryodes edulis. Endophytic fungi associated with healthy leaves of D. edulis were isolated using standard methods. The fungi were subjected to solid-state fermentation on rice media at 28°C for 21 days and the idiolites extracted using ethylacetate. The extracts of the endophytic fungi were evaluated for antimicrobial properties using agar well diffusion method against selected human pathogens. The endophytic fungi isolates were also characterized using macroscopy and microscopy (photomicrograph). A total of six (6) endophytic fungi (LB2, LB3, MR1, MR2, MR3, and MR4) were isolated from leaves of D. edulis. The extracts of isolated endophytic fungi displayed varying antimicrobial activities, with inhibition zone diameters ranging from 4 to 12 mm. The MR3 extract was the most effective metabolite and showed broad spectrum antimicrobial activity against Staphylococcus aureus, Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Endophytic fungi isolated from the leaves of D. edulis have antimicrobial activity and could be a hopeful source antimicrobial agent.