Adetuwo, O. J.; Ogundana, F. N.

The increasing prevalence of antifungal resistance among clinically relevant pathogens such as Candida albicans and Aspergillus fumigatus necessitates the exploration of novel bioactive compounds from sustainable sources. Mushrooms represent promising reservoirs of bioactive metabolites; however, the influence of cultivation substrates on their antifungal potential remains underexplored, particularly in tropical systems. This study investigated the antifungal and bioactive properties of Pleurotus ostreatus cultivated on three agro-waste substrates (Gmelina sawdust, oil palm fruit pressed fiber, and cassava peels) in Nigeria. Molecular identification was performed using ITS, LSU, and RPB2 markers to confirm species identity. Extracts were evaluated for antimicrobial activity against clinically relevant pathogens, including Candida albicans, and Aspergillus fumigatus alongside antioxidant potential. Results demonstrated that substrate type significantly influenced bioactivity, with mushroom extracts exhibiting notable antifungal activity against C. albicans, A. fumigatus and antibacterial effects against selected pathogens. Molecular profiling confirmed accurate species identification, supporting the reliability of downstream analyses. These findings highlight agro-waste-cultivated P. ostreatus as a promising source of antifungal agents and underscore the role of substrate-driven metabolic variation in shaping bioactive potential. Future integration of metabolomics and genome-informed approaches will enable the identification of underlying bioactive compounds and their mechanisms of action.