Characterization of Antimicrobial Compounds from Trichoderma flavipes Isolated from Freshwater Environments

Traditional antibiotic agents are commonly employed in the control of pathogenic microorganisms. However, there is a growing need for novel alternative antimicrobial agents owing to the increasing prevalence of resistance to these treatments. Freshwater fungi, recognized for producing diverse secondary metabolites with biological activities, offer promising sources for drug development. However, studies on Trichoderma flavipes remain limited. Therefore, this study was conducted to investigate the antimicrobial properties of bioactive compounds derived from Trichoderma flavipes FBCC-F1632, a fungal species isolated from freshwater environments in Korea. The fungal strain FBCC-F1632 was isolated from stream soil obtained from Mungyeon-si, Republic of Korea, and identified through DNA extraction and phylogenetic analysis. Antimicrobial activity against Staphylococcus aureus and Bacillus cereus was assessed, revealing significant inhibitory rates. Potential bioactive compounds were extracted, purified, and structurally characterized using chromatographic and spectroscopic techniques, including nuclear magnetic resonance and mass spectrometry. Five bioactive compounds were identified: F1632-1 (cordyol C), F1632-2 (diorcinol), F1632-3 (violaceol I), F1632-4 (tryptophol), and F1632-6 (violaceol II). These compounds exhibited notable antimicrobial activities, particularly against Staphylococcus aureus and Bacillus cereus, underscoring their potential as candidates for the development of novel antimicrobial therapeutics.