Metabolomic Insights into the Antimicrobial Effects of Metschnikowia Yeast on Phytopathogens

One of the most important features of <i>Metschnikowia pulcherrima</i> is its strong antimicrobial activity against phytopathogens, which makes it a suitable candidate for use in biocontrol during crop cultivation. However, the mechanisms of its antimicrobial activity are not currently well understood. In this study, we used metabolomic methods to investigate the possible mechanisms of antimicrobial activity by <i>M. pulcherrima</i> against phytopathogenic fungi. First, we tested the antimicrobial activity of five selected isolates against eleven phytopathogenic molds. Based on the results, selected yeast-pathogen co-cultures were cultivated on liquid and solid media. The supernatants from the liquid co-cultures were analyzed using the UHPLC-QToF-UHRMS and MS/MS methods. Co-culture growth on solid agar media was examined using the LARAPPI/CI MSI method. The yeast exhibited strong antagonism toward the mold phytopathogens. The LARAPPI/CI MSI method revealed the presence of various compounds with potential antifungal activity. The complex UHPLC-QToF-UHRMS analysis confirmed that the metabolic response of <i>M. pulcherrima</i> depends on specific yeast-pathogen interactions.