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Inhibition of Fungal Growth by Bacterial Volatiles

Ghazal Ebadzadsahrai: Midwestern University


<div>Bacterial volatile organic compounds (VOCs) are natural chemicals that have been implicated in interkingdom signaling and have potential applications as biological alternatives or supplements to synthetic chemicals for controlling fungi in sustainable agriculture. Sixty-eight bacterial isolates from wild and cultivated cranberry bogs were evaluated for VOC activity against <em>Phytophthora</em> spp., <em>Phomopsis</em> sp., <em>Coleophoma</em> sp., and <em>Trichoderma</em> sp. Volatile emissions from several <em>Chromobacterium </em>spp.<em> </em>inhibited all of the ascomycetes and oomycetes tested. In this study, we compared the volatile metabolomics of wild-type <em>C. vaccinii</em> with spontaneous Quorum-Insensitive (QI) mutants that have lost <em>acyl</em> homoserine lactone receptor function. Wild type strains were significantly more inhibitory against the tested fungi and oomycetes than the QI mutants. VOCs produced by <em>C. vaccinii</em> strains and one of the fungi were analyzed by 2D gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS). The metabolomes of wild type and QI <em>C. vaccinii </em>were compared, and candidate inhibitory VOCs from several chemical classes are currently being identified from wild type <em>Chromobacterium</em>.</div>