Analyses of stress resistance under laboratory conditions constitute a suitable criterion for wine yeast selection.

Abstract

During wine production, yeast cells are affected by several conditions that are adverse to growth (oxidative, osmotic and ethanol stress among others) and they should detect and respond to these conditions, otherwise alcoholic fermentation can be negatively affected. In this work we have analyzed the fermentative behaviour of 14 commercial and non-commercial strains in several synthetic musts. According to the data obtained these strains have been classified into three groups depending on whether or not vinification was completed (and on the amount of residual sugar remaining in the must if it was not). Moreover, we have determined the resistance of these strains to several stress situations under laboratory growth conditions. We have been able to establish a correlation between the groups based on fermentative behaviour and resistance to several stress conditions (especially oxidative and ethanol stress), by applying discriminant analysis to the data obtained in these experiments. Our results indicate a clear relationship between stress resistance and fermentative behaviour and this opens up the possibility of using this information as a criterion for the future selection of wine yeasts.