Utilization of antagonistic yeasts in grapes to control Botrytis cinerea

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Sebahat OZTEKIN

Istanbul Technical University, Turkey

: J Food Nutr Disor

Abstract

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There is a growing demand for biopreservatives that are natural and eco-friendly. Accordingly, yeasts are considered to be one of the promising biocontrol agents. In addition, the use of chemical pesticides may lead to health problems by inducing resistance in the fruit microbiome, which also poses a threat to theenvironment. Therefore, in this study, Metschnikowia sp. (Metschnikowia sinensis KTMD1-4, Metschnikowia pulcherrima BMD3B, and Metschnikowia aff. pulcherrima P01A016) yeasts were tested on grapes to control Botrytis cinerea infection. For all yeasts, in vitro mycelial growth inhibition rates were found above 80 %. Additional tests (iron depletion, volatile organic compounds (VOCs), and biofilm activity) were conducted on yeasts to elucidate the inhibition mechanisms. Then, antagonistic yeasts were tested on grapes to see the biocontrol efficacy against B. cinerea. The findings showed that M. pulcherrima BMD3B had the highest iron depletion activity and biocontrol efficacy in controlling B. cinerea, also maintaining the integrity of the fruit cell wall. Furthermore, M. sinensis KTMD1-4 had a moderate effect in controlling B. cinerea. Although Metschnikowia aff. pulcherrima P01A016 displayed the highest biofilm activity (0.88 ± 0.03) and VOCs formation, it was ineffective in controlling B. cinerea. Metschnikowia yeasts prolonged the shelf life of grapes by reducing the disease incidence and lesion diameters compared Metschnikowia pulcherrima BMD3B, and Metschnikowia aff. pulcherrima P01A016) yeasts were tested on grapes to control Botrytis cinerea infection. For all yeasts, in vitro mycelial growth inhibition rates were found above 80 %. Additional tests (iron depletion, volatile organic compounds (VOCs), and biofilm activity) were conducted on yeasts to elucidate the inhibition mechanisms. Then, antagonistic yeasts were tested on grapes to see the biocontrol efficacy against B. cinerea. The findings showed that M. pulcherrima BMD3B had the highest iron depletion activity and biocontrol efficacy in controlling B. cinerea, also maintaining the integrity of the fruit cell wall. Furthermore, M. sinensis KTMD1-4 had a moderate effect in controlling B. cinerea. Although Metschnikowia aff. pulcherrima P01A016 displayed the highest biofilm activity (0.88 ± 0.03) and VOCs formation, it was ineffective in controlling B. cinerea. Metschnikowia yeasts prolonged the shelf life of grapes by reducing the disease incidence and lesion diameters compared to control. These findings could pave the way for the use of natural yeasts as an alternative to synthetic pesticides.

Biography

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Sebahat OZTEKIN received her Master’s degree from Istanbul Technical University in 2014. She is currently working as a research assistant in the Department of Food Engineering at the Bayburt University, Turkey and pursuing a PhD in Istanbul Technical University. She does research on mycotoxigenic fungi, antagonistic yeasts,natural antimicrobial microorganisms, food microbiology and biotechnology.