The proteome of a wine yeast strain during fermentation, correlation with the transcriptome

Although wine yeast gene expression has been thoroughly investigated only few data are available on the evolution the proteome during alcoholic fermentation. This work aimed at specifying the change in proteome during fermentation and to assess its connection with transcriptome. The proteome of a wine yeast was monitored by 2-D gel electrophoresis throughout alcoholic fermentation. Proteome was analysed in exponential growth and stationary phase. Among 744 spots, detected we observed significant changes in abundance with 89 spots displaying an increase in intensity and 124 a decrease. We identified 59 proteins among the most regulated and/or the most expressed. Glycolysis and ethanol production, amino acid and sulfur metabolism were the most represented functional categories. We found only a weak correlation between changes in mRNA and protein abundance, which is strongly dependent on the functional category. There are substantial changes in protein abundance during alcoholic fermentation, but they are not directly associated with changes at transcript level suggesting that mRNA is selectively processed and/or translated in stationary phase. These data show that proteome is a relevant level of analysis to gain insight into wine yeast adaptation to alcoholic fermentation.