Flor Yeast Proteomic Response to the Lack of Fermentable Carbon Source

Abstract

Flor yeasts metabolism highly configures organoleptic properties in Sherry type wines during biological aging (Peinado et al., 2009). Along this process, the mentioned yeasts prevail by forming a biofilm in the wine surface and the presence of certain proteins involved in the response to stresses becomes essential for survival, among the most important ones: lack of fermentable carbon sources. The main aim of this study is to compare proteome data from the flor yeast Saccharomyces cerevisiae G1 in a typical biological aging condition (without fermentable carbon source) and in a fermentative condition (with fermentable carbon source). In this work, OFFGEL fractionator coupled to LTQ Orbitrap XL MS equipment were used trying to identify the maximum possible number of proteins related to the lack of fermentable carbon source stress in a synthetic biological aging and under a reference fermentative condition. As a result, 18 stress proteins responding to the lack of fermentable carbon source have been detected only in the biological aging condition or higher than in the reference condition which are involved in biofilm formation, perception of stimuli among other biological processes. This study together with other experiments that definitively confirm the necessity of these proteins synthesis, may lead to the genetic improvement of flor yeast strains aimed to enhance their survival during the biological aging process and hence the whole wine elaboration process.