A Comparative Examination of Antimicrobial Activity in Fruiting Body and Submerged Culture Extracts of Basidiomycetes

Antimicrobial metabolite production in basidiomycetes varies by strain and growing conditions. This study compared the antimicrobial activity of extracts from nine fungal strains at both their vegetative and reproductive stages. Wild-growing fungal fruiting bodies were collected and identified through both morphological characterization and molecular sequencing. Extracts from fruiting bodies, mycelia, and culture liquids were tested using the agar well diffusion method and by determining the minimum inhibitory concentration (MIC). Analysis revealed that the highest antimicrobial activity was associated with culture liquid extracts. Antimicrobial properties were detected in the submerged mycelium extracts of only two strains: Stereum hirsutum 1 and Flammulina rossica 16. For fruiting bodies, activity was restricted to extracts of strains from the genus Fomitopsis. The strain S. hirsutum 1 was determined to be the most effective producer of antibacterial compounds. The highest activity was exhibited by the S. hirsutum 1 culture liquid extract, with an MIC of 320 µg/mL against clinical Gram-positive strains (Staphylococcus aureus, S. epidermidis, S. haemolyticus, vancomycin-resistant Enterococcus faecium) and Gram-negative Proteus vulgaris. The studied strains demonstrated higher production of antimicrobial metabolites during vegetative growth, with the active compounds being primarily extracellular. Submerged cultivation of basidiomycetes offers an efficient method for obtaining antimicrobial metabolites, permitting their subsequent isolation, physicochemical characterization, and biomedical evaluation.