Surfome analysis of a wild-type wine Saccharomyces cerevisiae strain

The yeast Saccharomyces cerevisiae, besides being an eukaryotic cell model, plays a fundamental role in the production of fermented foods. In the winemaking industry, yeast cell walls may be involved in numerous processes and contribute substantially to the final chemical and sensorial profiles of wines. Nonetheless, apart from mannoproteins, little is known on the protein components of the yeast cell wall and their changes during the fermentation of must into wine. In this work, we performed a dynamic analysis of the cell surface proteome (surfome) of an autochthonous wine yeast strain (previously selected as a wine fermentation starter) by shaving intact cells with trypsin and identifying tryptic peptides by means of nLC-ESI-LIT-MS/MS. Out of the 42 identified proteins, 16 and 14 were found to be specifically expressed in wine yeast surfome at the beginning and at the end of fermentation, respectively. The molecular functions of these specifically expressed proteins might help in explaining their roles in the cell wall as a response to the alcoholic fermentation-related stresses. Additionally, we provided the identification of 20 new potential cell wall related proteins. Globally, our results might provide new useful data for the selection and characterization of yeast strains to be used in the winemaking industry.