Diversity of endophytic fungi from medicinal plant Oxalis latifolia and their antimicrobial potential against selected human pathogens

Endophytic fungi that inhabit medicinal plants are microbial resources renowned for having compounds analogous to those produced by their host plants. This study aimed to describe the diversity of endophytic fungi found in Oxalis latifolia Kunth. To better understand the diversity of foliar endophytic fungi found in the leaves of the medicinal plant Oxalis latifolia, we isolated and characterized endophytic by using both morphological and molecular methods employing ITS markers. The antimicrobial activity of endophytic fungi against common human pathogens Escherichia coli, Staphylococcus aureus, and Bacillus subtilis was also investigated. A Total of 16 endophytic fungi were successfully isolated from leaves and classified into five orders of Pezizomycotina based on the phylogenic analyses; Xylariales (56%), Diaporthales (19%) Sordariales (6%), Glomerellales (13%) and Botryosphaeriales (6%). The antimicrobial activity of crude extracts from fungal endophyte against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis revealed that three isolates; N. aurantiaca, Phyllosticta capitalensis N. oryzae were the most potent, while Colletotrichum karstii and N. sphaerica displayed no growth inhibition property against the tested organism. The diversity indices were calculated by using the Shannon-Wiener, Margalef, and Simpson indices. The diversity indices analysis revealed an abundance of species diversity, where the dominant species were Nigrospora oryzae, N. sphaerica, and Colletotrichum karstii. This study describes the diversity of endophytic fungi found in O. latifolia and emphasizes their potential as a source of novel bioactive compounds. More research on phytochemical composition and antimicrobial activity is ongoing to correlate the traditional uses and scientific findings.