Oxidative stress effect before fermentation to bioethanol and alcoholic beverages production

Abstract

During ethanol and alcoholic beverages production, yeast cells are affected by several stress 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 behavior of four commercial and non‐commercial strains in synthetic musts. The yeast used were two Saccharomyces cerevisiae and two Kluyveromyces marxianus, isolated from mezcal processes in México. According to the data, indicate that common patterns of stress response are found among all the strains and can been classified into three groups depending on whether or not alcoholic fermentation was completed. The oxidative stress with H2O2 decreased the specific growth rate during the fermentation more than the stress induced by menadione, but the ethanol production at the end of the fermentation, not showed a significant difference between the H2O2 and the menadione. Our results indicate a clear relationship between stress resistance and fermentative behavior and this opens up the possibility of using this information as a criterion for the future selection of bioethanol and alcoholic beverages yeasts.