Antifungal VOCs produced by Meyerozyma spp.: Insights from PCA and PLS-DA in mono- and co-cultures against phytopathogens.

This is the first study to perform PCA and PLS-DA analyses to obtain the main volatile organic compounds (VOCs) with antifungal properties produced by monocultures of Meyerozyma caribbica (C) and Meyerozyma guilliermondii (G), and the mixed C:G culture against Rhizopus stolonifer and Lasiodiplodia theobromae. A wide variety of VOCs was obtained, with the chemical classes most produced by all cultures being alcohols and terpenes, followed by a smaller range of organic acids, aldehydes, ketones, and esters. The mixed culture presented a greater variety and abundance of VOCs with antimicrobial activity. Up to 56 VOCs were produced against R. stolonifer under varying incubation conditions, while up to 50 VOCs were produced against L. theobromae. The presence of R. stolonifer and L. theobromae pathogens increased the abundance of VOCs produced, as a yeast defense response, decreasing the three-dimensional mycelial development in both pathogens and the radial development against L. theobromae. PCA analysis was used on the VOCs of the highest importance value (VIP) obtained by PLS-DA to identify the culture that produced the highest number of VOCs responsible for antifungal activity. This study reveals how M. caribbica and M. guilliermondii yeasts, both in monocultures and mixed cultures, can produce various volatile organic compounds (VOCs) with antagonistic properties. It also highlights how the quantity of these VOCs changes depending on the presence of phytopathogens and factors like incubation time and temperature.