Changes in quality and microbiome composition of strawberry fruits following postharvest application of Debaryomyces hansenii, a yeast biocontrol agent

Microbial antagonists provide a new perspective on biological control by altering microbial diversity to control postharvest diseases of fruit. In this study, the biological control effect of Debaryomyces hansenii on postharvest diseases of strawberry and the influence on strawberry quality were determined. At the same time, the effect of D. hansenii on the composition of surface microbiome of strawberry fruit was analyzed by high-throughput sequencing technology. The results showed that D. hansenii treatment can inhibit the natural decay rate of strawberries, and the treatment group maintained a higher ascorbic acid content than the control group. However, there was no difference between the control and treatment groups in firmness, weight loss rate, soluble solids, titratable acidity, and other quality indicators. On the surface of strawberries treated with D. hansenii, the diversity of fungal community was changed, the composition and structure of the community were also altered (except the abundance of Debaryomyces spp.). Strawberries treated with D. hansenii could alter bacterial and fungal populations, inhibit plant pathogens, and lower the frequency of postharvest diseases in strawberries. This study helps to understand the microbial community structure on the surface of strawberries and guides the synthesis of strawberry postharvest disease complex biocontrol strains to achieve stable and sustainable postharvest disease control strategies of the fruits.