Exploring the Exo-Metabolomes and Volatile and Non-Volatile Compounds of Metarhizium carneum and Lecanicillium uredinophilum.

Abstract

Efforts are intensifying to identify bioactive microbial metabolites from biocontrol agents to manage plant pathogens in critical crops. This study examined both volatile organic compounds (VOCs) and non-volatile compounds from Metarhizium carneum and Lecanicillium uredinophilum strains for their antimicrobial effects against various phytopathogens and analyzed their exo-metabolomes. M. carneum VOCs inhibited four bacterial and eight fungal species by up to 45.45%, while L. uredinophilum VOCs inhibited five bacterial and eight fungal species by up to 50.91%. Additionally, n-BuOH extracts from both biocontrol agents effectively targeted three fungi and five bacteria. The exo-metabolomes of M. carneum and L. uredinophilum included 125 and 102 spectrometric features, respectively, primarily consisting of polyketides, alkaloids, lipids, organic aromatic compounds, terpenoids, and peptides. Our findings revealed a correlation between the phylogenetic relationships of M. carneum strains, their bioactivity patterns against phytopathogens, and their metabolomic profiles. Notably, some compounds detected in both fungi previously demonstrated biological activity against plant pathogens, enhancing their biocontrol potential. This study not only evidences the antimicrobial properties of diffusible compounds from M. carneum and L. uredinophilum, but also documents the antimicrobial potential of their VOCs for the first time, supporting their use in sustainable agricultural practices, reducing reliance on chemical inputs.