Volatile organic compounds (VOCs) produced by biocontrol yeasts

The Volatile organic compounds (VOCs) produced by biocontrol yeast strains which belong to the Wickerhamomyces anomalus, Metschnikowia pulcherrima, Aureobasidium pullulans and Saccharomyces cerevisiae species were identified by solid phase microextraction (SPME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS). Alcohols (ethyl alcohol, 3-methyl-1-butanol and phenylethyl alcohol) and esters (ethyl acetate and isoamyl acetate) were found to be the main VOCs emitted by the yeast strains, which had different production rate over a 16-day period. In addition, the tested yeast strains showed a remarkable ability to consume oxygen and to produce high percentages of carbon dioxide over a 5 days incubation period in a model system. The yeast strains, which were proven to very efficiently suppress in vivo the growth of postharvest fungal by VOCs, also quickly produced high percentages of ethyl acetate and carbon dioxide. . For all these reasons, we believe that the level of yeast biocontrol efficacy through the production of volatiles could be the result of a synergistic effect between VOCs and carbon dioxide in the packaging environment.