Metabolomic Measurements at Three Time Points of a Chardonnay Wine Fermentation with Saccharomyces cerevisiae

The transformation of grape juice to wine is a complex metabolic relationship between two species, the grape plant Vitis vinifera and yeast, primarily Saccharomyces cerevisiae. The final molecular composition resulting from the grape-yeast relationship contributes to the flavor, aroma, and mouthfeel of the wine. In this study, we examined this complex relationship by determining the exo- and endo-metabolome (the collection of metabolites present extra-and intracellularly, respectively) of yeast at three time points (days 4, 9, and 15) of a Chardonnay wine fermentation. We identified and tracked 227 metabolites in the exo-metabolome and 404 metabolites in the endometabolome, and each metabolite was grouped into metabolic pathways or into metabolite families. Considerable metabolic variation was present at each stage of the fermentation, illuminating metabolic patterns suggesting that regulation of the yeast metabolic pathways is coupled to the fermentation progress. Analysis of the differential utilization and production of primary and secondary metabolites during a wine fermentation in this work provides a key understanding of cell-communication mechanisms relevant to metabolic engineering and industrial biotechnological processes.