Transcriptomic and proteomic insights of the wine yeast biomass propagation process.

Transcriptome and proteome profiles have been established for the commercial wine yeast strain T73 during an important industrial process: yeast biomass propagation. The data from both analyses reveal that the metabolic transition from fermentation to respiration is the most critical step in biomass propagation. We identified 177 ORFs and 56 proteins among those most expressed during the process, thus highlighting cell stress response, mitochondrial and carbohydrate metabolism as the most represented functional categories. A direct correlation between mRNA changes and protein abundance was observed for several functional categories such as tricarboxylic acid cycle proteins, heat shock proteins, chaperons and oxidative stress response-related proteins. However, we found no concordance in the transcript and proteomic levels for glycolytic proteins, which is probably due to post-translational modifications increasing the number of protein isoforms, especially at the end of biomass propagation. The correlation between protein abundance and the enzyme activities of alcohol dehydrogenase, pyruvate decarboxylase and glyceraldehyde-3-phosphate dehydrogenase was not affected by these modifications. We suggest post-translational mechanisms during biomass propagation that affect the stability of those proteins that play an important role in the produced biomass' fermentative capacity.