Genome-guided characterization of Metschnikowia persimmonesis KCTC 12991BP against persimmon anthracnose

Global persimmon production declined from 4.5 to 4.2 million tonnes between 2017 and 2020 despite an expansion in harvested area, with anthracnose caused primarily by Colletotrichum gloeosporioides among factors affecting postharvest fruit losses. Metschnikowia persimmonesis KCTC 12991BP, a yeast isolated from the persimmon calyx, has shown antagonistic activity against postharvest pathogens, but its efficacy against persimmon anthracnose and the traits underlying this activity remain insufficiently characterized. This study evaluated the antifungal potential of KCTC 12991BP against C. gloeosporioides using genome mining, in vitro phenotyping, metabolite profiling, volatile double-plate assays, and in vivo fruit trials. Genome annotation with antiSMASH and dbCAN identified putative biosynthetic gene clusters associated with non-ribosomal peptide and terpene pathways, along with carbohydrate-active enzyme families with predicted roles in fungal cell-wall degradation. In dual-culture assays, inhibition of C. gloeosporioides varied among media and was enhanced under ferric-ion supplementation, supporting a potential role of iron-associated competition, possibly linked to pulcherrimin-related metabolism. Untargeted ultra-high performance liquid chromatography tandem mass-mass spectrometry (UPLC-MS/MS) analysis revealed distinct metabolite profiles between high- and low-inhibition conditions, while headspace solid phase microextraction gas chromatography-mass spectrometry (HS SPME GC–MS) identified 2-methyl-1-butanol (2 MB), 3-methyl-1-butanol (3 MB), and phenethyl alcohol (PEA) as dominant volatile organic compounds (VOCs), with double-plate assays showing dose-dependent suppression of fungal growth. The yeast also exhibited β-1,3-glucanase and protease activities and formed biofilms in vitro, suggesting traits that may contribute to antagonism or fruit-surface colonization. In wounded persimmon fruit, KCTC 12991BP-treated fruit exhibited reduced mean lesion diameter (0.435 cm) and disease incidence (70%) compared with untreated controls (0.783 cm and 100%, respectively) after 7 days. These findings identify KCTC 12991BP as a promising biocontrol candidate against postharvest persimmon anthracnose, providing a foundation for further mechanistic and applied validation. Key points KCTC 12991BP reduced anthracnose lesions in fruit and suppressed C. gloeosporioides growth in vitro Ferric ions enhanced KCTC 12991BP antagonism, implicating iron competition in C. gloeosporioides control VOCs caused dose-dependent C. gloeosporioides suppression, highlighting contact-free control