Postharvest treatment with Bacillus velezensis LX mitigates disease incidence and alters the microbiome on kiwifruit surface

Microbial communities on plant surfaces are crucial in regulating plant growth and disease control. Exploring the composition of microorganisms on plant surfaces is essential for understanding their potential functions. The restructuring of microbial communities can help reduce postharvest diseases and maintain fruit quality. In this study, the use of Bacillus velezensis LX fermentation broth resulted in a reduction of Diaporthe and Fusarium abundance on the surface of kiwifruit, as well as changed in the fungal and bacterial communities on the kiwifruit surface, as determined by high-throughput sequencing. B.velezensis LX treatment reduces the natural decay incidence of postharvest kiwifruit but does not decrease the quality of kiwifruit. An analysis of the relationship between microbial taxa and fruit decay incidence revealed that several genera, including Plectosphaerella, Vishniacozyma, Cryptococcus, Papiliotrema, Aureobasidium, Filobasidium, Actinomycetospora, and Parasutterella, were enriched in the CK and LX treatment group during storage. This study contributes to a better understanding of how microbial antagonists regulate postharvest diseases in kiwifruit and provides insights for establishing a beneficial microbial synthetic flora to enhance the postharvest safety of kiwifruit.