Volatile organic compounds produced by Antarctic strains of Candida sake play a role in the control of postharvest pathogens of apples

- Psychrotrophic yeasts isolated from Antarctica were used as biocontrol agents.
- VOCs produced by Candida sake strains inhibited apple pathogens.
- The VOCs produced by C. sake 41E were identified using SPME GC-MS.

In this study the strategy of isolating psychrotrophic, non-pectinolytic yeasts able to grow in apple juice as potential biocontrol agents was a successful approach. Thirty-four yeasts isolated from Antarctic were able to maintain rot incidence caused by P. expansum and B. cinerea under 25% on apples stored at 0-1 °C. Two of the isolates, identified as Candida sake, produced antifungal volatile organic compounds (VOCs) which inhibited the growth of five pathogens of apple (P. expansum, B. cinerea, A. alternata, A. tenuissima, and A. arborescens). This is the first report of VOCs produced by C. sake, as well as the first study of the inhibitory activity of VOCs produced by yeasts against species of Alternaria that cause postharvest apple rot.In vitro studies were performed on Apple Juice Agar at 0 °C and 25 °C due to the importance of evaluating antifungal activity in similar conditions to where the biocontrol agent are intended to be used. The VOCs produced by Candida sake strain 41E were also effective on in vivo assays to control P. expansum in Red Delicious apples.