Exploring the stress mechanism of tannic acid on Saccharomyces cerevisiae based on transcriptomics

Tannic acid is a polyphenolic substance widely in fruits, but the effect of tannic acid in fruit wine fermentation on Saccharomyces cerevisiae is still unknown. This study used tannic acid (1.6 g/L) to treat S. cerevisiae, the mechanism of the influence of tannic acid on the S. cerevisiae was further explored through transcriptomics technology. The results showed that the growth, ethanol yield and volatile substances of S. cerevisiae under tannic acid stress decreased by 71.76%, 46.49% and 85.58%, respectively. The activities of PDC and ADH of ethanol metabolism pathway decreased by 9.26% and 57.82%, respectively. Transcriptomic analysis showed that a total of 2890 differentially expressed genes were identified, of which 1499 genes were upregulated and 1391 genes were downregulated. Genes associated with the cell cycle, meiosis, and TCA cycle pathways were significantly induced, so S. cerevisiae responded to tannic acid stress through sexual reproduction and energy metabolism. The downregulation of genes related to cell wall integrity indicated that tannic acid destroyed the structure of the cell wall and inhibited its growth. In addition, downregulation of genes encoding glycolysis and pentose phosphate pathways were observed, resulting in significant inhibition of the ethanol metabolism pathway of S. cerevisiae. This study initially revealed the stress mechanism of tannic acid on S. cerevisiae and provided a basis for further studies to improve the tolerance in S. cerevisiae.