Transcriptional analysis and key genes associated with sugar, amino acid and organic acid metabolism in Saccharomyces cerevisiae during wine-making combined with Torulaspora delbrueckii

Abstract

In this study, the effect of mixed culture of T. delbrueckii/S. cerevisiae on the early transcriptional changes of S. cerevisiae (48 h) in actual wine-making process was investigated, and a simple fermenter equipped with dialysis bag was designed and used. Transcriptome profiling showed a total of 446 differentially expressed genes were detected in S. cerevisiae compared to its single fermentation. Several metabolites including sugars, amino acids and organic acids were determined throughout fermentation, and leucine, proline and malic acid had diverse evolutions in the mixed and single cultures. By integrating the transcriptomic results and various metabolites determination results, several metabolic pathways were found to be affected as a result of mixed culture, including glycolysis, phosphopentose pathway, TCA cycle and amino acid metabolism. Furthermore, gene expression levels associated with those metabolites were analyzed, and HXT2, HXK2, ERR, AGP1, AAT2, LEU2, ARO9, SDH9 and ICL1 were found with significant variations. Overall, our study provides knowledge on the gene discovery and deep understanding of the metabolism mechanism of S. cerevisiae in the presence of T. delbrueckii.