AUTHOR=Toral Laura , Rodríguez Miguel , Martínez-Checa Fernando , Montaño Alfredo , Cortés-Delgado Amparo , Smolinska Agnieszka , Llamas Inmaculada , Sampedro Inmaculada 

TITLE=Identification of Volatile Organic Compounds in Extremophilic Bacteria and Their Effective Use in Biocontrol of Postharvest Fungal Phytopathogens

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.773092

DOI=10.3389/fmicb.2021.773092

ISSN=1664-302X

ABSTRACT=<p>Phytopathogenic fungal growth in postharvest fruits and vegetables is responsible for 20–25% of production losses. Volatile organic compounds (VOCs) have been gaining importance in the food industry as a safe and ecofriendly alternative to pesticides for combating these phytopathogenic fungi. In this study, we analysed the ability of some VOCs produced by strains of the genera <italic>Bacillus</italic>, <italic>Peribacillus</italic>, <italic>Pseudomonas</italic>, <italic>Psychrobacillus</italic> and <italic>Staphylococcus</italic> to inhibit the growth of <italic>Alternaria alternata</italic>, <italic>Botrytis cinerea</italic>, <italic>Fusarium oxysporum</italic>, <italic>Fusarium solani</italic>, <italic>Monilinia fructicola</italic>, <italic>Monilinia laxa</italic> and <italic>Sclerotinia sclerotiorum</italic>, <italic>in vitro</italic> and <italic>in vivo</italic>. We analysed bacterial VOCs by using GC/MS and 87 volatile compounds were identified, in particular acetoin, acetic acid, 2,3-butanediol, isopentanol, dimethyl disulphide and isopentyl isobutanoate. <italic>In vitro</italic> growth inhibition assays and <italic>in vivo</italic> experiments using cherry fruits showed that the best producers of VOCs, <italic>Bacillus atrophaeus</italic> L193, <italic>Bacillus velezensis</italic> XT1 and <italic>Psychrobacillus vulpis</italic> Z8, exhibited the highest antifungal activity against <italic>B. cinerea</italic>, <italic>M. fructicola</italic> and <italic>M. laxa</italic>, which highlights the potential of these strains to control postharvest diseases. Transmission electron microscopy micrographs of bacterial VOC-treated fungi clearly showed antifungal activity which led to an intense degeneration of cellular components of mycelium and cell death.</p>