Genome-Guided Metabolomic Profiling of Peptaibol-Producing Trichoderma

Peptaibols are linear fungal peptides featuring α,α-dialkylated amino acids (e.g., α-aminoisobutyric acid (Aib), isovaline (Iva)) and characteristic C-terminal alcohol groups. Despite their promising antibacterial and antiplasmodial activities, detailed biosynthetic studies remain limited. A genome-guided study of the fungus <i>Trichodema</i> sp. SK1-7, isolated from decaying wood, revealed the production of previously described trichorozin IV (<b>1</b>), along with novel SF4-type peptaibol <b>2</b> (trichorozin V). The structures of these compounds were elucidated through MS analysis, NMR study and advanced Marfey's method. The genome of <i>Trichoderma</i> sp. SK1-7 harbors two PKS-NRPS hybrid gene clusters containing 14 and 18 adenylation domains. Analysis of the modular architecture suggested that trichorozins are synthesized by a 14-module protein via a module skipping mechanism. Genome mining revealed several types of short peptaibol synthase architectures (10-14 adenylation domains) across various <i>Trichoderma</i> species, accompanied by similar long peptaibol synthases. Furthermore, putative Aib/Iva biosynthesis machinery in <i>Trichoderma</i> was identified, showing specific architectures potentially involved in regulating peptaibol biosynthesis. Feeding experiments demonstrated that peptaibol production depends on the ratio of Iva/Aib. The isolated compounds exhibited moderate antibacterial and cytotoxic activities along with a synergistic effect when combined with membrane-targeting antibiotics. Our findings suggest that genome-guided approaches hold promise for further development of peptabiotics with a wide range of applications, including antibiotic adjuvants.