Antibacterial Activity of Bioactive Compounds from Endophytic Fungi against P. aeruginosa isolated from Freshwater Fishes

With the increasing occurrence of bacterial resistance against available antibiotics, it has now become necessary to investigate newer sources for antimicrobials. Endophytic fungi have the aptitude to co-exist with their host plants without affecting any harm and are useful to both the plant and the fungi. The current study aimed to evaluate the antimicrobial activity of the bioactive compounds of some endophytic fungi isolated from five medicinal plants against  P. aeruginosa. A total of 30 distinct colonies of the endophytic fungi were isolated from five selected medicinal plants. Most of





the isolates were obtained from H. sabdariffa L., O. europaea L., M. piperita L., M. oleifera Lam. and A. indica A. Juss. Most of the fungal isolates belonged to Alternaria sp., Cladosporium sp., Ulocladium sp., Chaetomium sp., A. niger, E. nidulans  and Fusarium sp. A total of 34 intra- and extra-cellular metabolites from 17 endophytic fungal isolates were evaluated for their antibacterial activities against P. aeruginosa, some endophytic fungal metabolites showed antibacterial activities as A. niger extract isolated from neem which exhibited the most potent antibacterial activity16.5± 0.71 mm against P. aeruginosa. In addition, Cladosporium, sp. isolated from neem, Chaetomium sp. extracts and Alternaria sp. (isolated from mint), showed antibacterial activity with the zone of inhibition, 13± 1.41, 12.5± 0.71and 12.5± 0 mm, respectively. In contrast, none of the Ulocladium sp., Alternaria sp. extracts (isolated  from olive), Cladosporium sp., and E. nidulans extracts (isolated from mint) showed any antibacterial activities  against P. aeruginosa