Combining the biocontrol yeast Pichia kluyveri with UV-C treatment to control postharvest decay of king oyster mushrooms (Pleurotus eryngii) caused by Lactococcus lactis subsp. lactis

Postharvest decay and senescence results in significant losses in harvested mushrooms. Integrated management, utilizing different eco-friendly, non-chemical methods, represents a strategy for controlling postharvest decay and reducing economic losses in horticultural crops that is being actively developed and commercialized. In the present study, the use of the biocontrol yeast Pichia kluyveri combined with UV-C treatment was evaluated for its ability to control postharvest decay of king oyster mushrooms (Plerrotus eryngii) caused by Lactococcus lactis subsp. lactis. As stand-alone treatments, the use of P. kluyveri or UV-C significantly reduced disease development, relative to untreated mushrooms. The control effects on L. lactis decay and natural infection were significantly improved by the combination of P. kluyveri and UV-C, compared to either treatment alone. Treatment of mushrooms with P. kluyveri or UV-C alone and in combination also induced the activity the antioxidant enzymes of catalase and superoxide dismutase in treated mushrooms, and also enhanced the accumulation of antimicrobial substances, such as total phenolics and flavonoids. These data indicate that the mode of action by which UV-C enhances the biocontrol efficacy of P. kluyveri may be partially attributed to the elicitation of host defense responses in mushrooms. Integrating the use of a biocontrol agent with UV-C treatment represents an effective strategy for controlling postharvest decay in mushrooms.