Correlations between microbiota with physicochemical properties and volatile compounds during the spontaneous fermentation of Cabernet Sauvignon (Vitis vinifera L.) wine

Understanding the diversity and evolution of microorganisms during wine fermentation is essential for controlling its production. However, the flavors profiles associated with microbiota changes during the spontaneous fermentation have not yet been described in detail. In this study, we explored the correlations between microbial community with physicochemical properties and flavor components during the spontaneous fermentation of Cabernet Sauvignon wine. Microbial community diversity at different fermentation stages was identified using high-throughput sequencing, and physicochemical properties and volatile compounds were identified through fermentation features testing and headspace solid phase microextraction gas chromatography mass spectrometry. First, the diversity of the fungi community decreased with the fermentation process, whereas the bacteria did not change significantly until the end of the fermentation. Second, the changes of the fermentation environment had reshaped the diversity and composition of the microbial community. Finally, Aureobasidium, Cladosporium, Filobasidium, Hanseniaspora, Hannaella, Saccharomyces, Alternaria, Wickerhamomyce, Starmerella, Candida, Papiliotrema, Bradyrhizobium, Gluconobacter, Leuconostoclia, Comamonas, Acetobacter, and Massilia, were significantly correlated with changes of physicochemical properties and volatile compounds. Overall, our research results provide important insights for understanding the metabolically active microbiota, which is conducive to the expression of wine "terroir".