Evaluation of Antibacterial Potency of Endophytic Fungi Isolated from Mentha piperita

The Mentha piperita is an aromatic perennial herb, a member of the family Lamiaceae (Labiatae) that produces creeping stolons, growing in the range of 45 to 80 cm tall. Fungal endophytes reside in the healthy plant tissues to produce several metabolic products such as plants growth hormones, anti-phagocytes to biological feeding, medicinal ingredients, and many products of biological activities. Hence, they are regarded as a reservoir of active metabolites for the development of novel drugs. Although, many endophytic fungi have been reported from different plants, reports on fungal endophytes from M. piperita are very limited. In this study, fungal endophytes from the leaf and stem of M. piperita were successfully evaluated for their potential antibacterial properties. Healthy leaves of the peppermint were prepared and cultured on potato dextrose agar (PDA) plates for 5 to 7 days at 28 oC until fungal colonies appeared. Fifteen (15) fungal isolates were identified based on cultural and morphological characteristics and had six (6) rapid growing species, namely Aspergillus fumigatus, Rhizopus arrhizus, Aspergillus flavus, Fusarium oxysporum, Aspergillus niger, Alternaria alternate which were selected and evaluated their crude metabolites against c using agar well diffusion method. The susceptibility study showed a remarkable in vitro antibacterial activity of the fungal crude metabolites against all the test bacteria which increased with an increased incubation time of 7, 14 and 21 days incubation. However, the fungi displayed maximal zone of growth inhibition after 21 days of incubation. In conclusion, fungal endophytes were isolated from M. piperita and evaluated in vitro antibacterial activity of their crude metabolites against the test bacterial isolates