Enological properties in wild and commercial Saccharomyces cerevisiae yeasts: relationship with competition during alcoholic fermentation

Commercial yeasts are widely used in winemaking to carry out the alcoholic fermentation; nevertheless, some wild strains may compete with them and even dominate the process. In this research, 21 prevailing wild strains isolated from inoculated musts were chosen in order to study the competition between them and commercial yeasts. Some biotechnological properties which could enhance their performance during the process were also studied, such as vitality, killer factor, resistance to high concentrations of sugar, ethanol and SO 2 or trehalose and glycogen cell content. All yeasts, both commercial and wild strains, showed resistance to the killer toxin and they were all able to growth under adverse conditions. However, vitality and carbohydrate content were strain dependent in around 70% of the cases; the wild strain had a higher vitality and accumulated less trehalose than its commercial counterpart.