Antioxidant defense parameters as predictive biomarkers for fermentative capacity of active dried wine yeast

• Published in: Biotechnology journal 2014-08, Vol.9 (8), p.1055-1064
• Main Authors: Gamero-Sandemetrio, Esther, Gómez-Pastor, Rocío, Matallana, Emilia
• Format: Article
• Language: English
• Subjects: Active dry wine yeasts; Antioxidant defenses; Antioxidants - metabolism; Biomarkers - analysis; Fermentation; Gene Expression Regulation, Fungal; Glutathione; Glutathione - metabolism; Macromolecular damage; Saccharomyces cerevisiae; Saccharomyces cerevisiae - classification; Saccharomyces cerevisiae - isolation & purification; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Trehalose; Trehalose - metabolism; Vitaceae; Wine - microbiology; Yeast, Dried - analysis
• ISSN: 1860-6768; 1860-7314
• DOI: 10.1002/biot.201300448

The production of active dried yeast (ADY) is a common practice in industry for the maintenance of yeast starters and as a means of long term storage. The process, however, causes multiple cell injuries, with oxidative damage being one of the most important stresses. Consequentially, dehydration tolerance is a highly appreciated property in yeast for ADY production. In this study we analyzed the cellular redox environment in three Saccharomyces cerevisiae wine strains, which show markedly different fermentative capacities after dehydration. To measure/quantify the effect of dehydration on the S. cerevisiae strains, we used: (i) fluorescent probes; (ii) antioxidant enzyme activities; (ii) intracellular damage; (iii) antioxidant metabolites; and (iv) gene expression, to select a minimal set of biochemical parameters capable of predicting desiccation tolerance in wine yeasts. Our results show that naturally enhanced antioxidant defenses prevent oxidative damage after wine yeast biomass dehydration and improve fermentative capacity. Based on these results we chose four easily assayable parameters/biomarkers for the selection of industrial yeast strains of interest for ADY production: trehalose and glutathione levels, and glutathione reductase and catalase enzymatic activities. Yeast strains selected in accordance with this process display high levels of trehalose, low levels of oxidized glutathione, a high induction of glutathione reductase activity, as well as a high basal level and sufficient induction of catalase activity, which are properties inherent in superior ADY strains. Dehydration tolerance is an important quality in the production of active dried yeast (ADY). In this article, the authors assessed fermentative capacity following dehydration in three enological strains of Saccharomyces cerevisiae and propose four easily assayable parameters for the selection of industrial yeast strains, with potential interest for ADY production.