Role of Antarctic yeast in biocontrol of Penicillium expansum and patulin reduction of apples

Abstract

Apple is among the main fruit crops in Uruguay. After harvest apples are stored at low temperatures. Despite this storage condition, Penicilliumexpansum, one of the most important postharvest pathogens worldwide, develops on apples. This fungus produces patulin, a secondary metabolite with toxic effects in mammals. Patulin contamination control of apples currently relies mainly on the use of fungicides. However, the use of biological control agents is a promising friendly alternative and some commercial products have been developed. In this work five psychrotrophic yeasts isolated from cold environments were evaluated as biocontrol agents of P.expansum rot on apples. Experiments were done during 3 months under cold storage conditions, followed by further storage at room temperature. Among the tested Antarctic yeasts, Candida sake 41E effectively controlled fungal growth on apples at cold and room temperature. This yeast also reduced patulin concentration in apple juice at room temperature, without adsorption to the cell walls. These characteristics suggest that this strain may be a promising biocontrol agent of blue mold.