"Edible plant-associated fungal endophytes as sources of bioactive specialized metabolites: antimicrobial and docking insights".

Endophytic fungi have emerged as prolific sources of structurally diverse and biologically potent specialized metabolites with significant therapeutic potential. In this study, endophytic fungi were isolated from three edible plant species: Raphanus sativus, Eruca sativa, and Allium porrum, to systematically assess their biodiversity and antimicrobial capabilities. A total of twenty-six fungal isolates were obtained, of which seven were prioritized for detailed morphological and functional characterization based on preliminary bioactivity screening. Among these, Fusarium oxysporum (A1/APFE1) and Aspergillus niger (E2/RSFE2) exhibited pronounced and broad-spectrum antimicrobial activity against clinically and agriculturally relevant pathogens, including Candida albicans (ATCC 10231), Pseudomonas aeruginosa (ATCC 27853), and Staphylococcus aureus (ATCC 29213), under both solid-state and submerged culture conditions. Phylogenetic characterizations for the two endophytic isolates were performed. Ethyl acetate extracts of these two strains were subjected to high-resolution LC-HR-ESI-MS metabolomic profiling, which demonstrated a chemically varied range of specialized metabolites, including terpenoids, polyketides, macrolides, and phenolics. Subsequent in silico molecular docking analyses highlighted specific metabolites with strong binding affinities to dihydrofolate reductase, providing mechanistic insights into the observed antimicrobial activity. Collectively, these results position F. oxysporum (A1/APFE1) and A. niger (E2/RSFE2) as promising candidates for the development of novel antimicrobial agents, highlighting the edible plant-associated endophytic fungi's unrealized medicinal potential.