Stress tolerance: The key to effective strains of industrial baker's yeast

Application of yeasts in traditional biotechnologies such as baking, brewing, distiller's fermentations, and wine making, involves them in exposure to numerous environmental stresses. These can be encountered in concert and sequentially. Yeast exhibit a complex array of stress responses when under conditions that are less than physiologically ideal. These responses involve aspects of cell sensing, signal transduction, transcriptional and posttranslational control, protein-targeting to organelles, accumulation of protectants, and activity of repair functions. The efficiency of these processes in a given yeast strain determines its robustness, and to a large extent, whether it is able to perform to necessary commercial standards in industrial processes. This article reviews aspects of stress and stress response in the context of baker's yeast manufacturing and applications, and discusses the potential for improving the general robustness of industrial baker's yeast strains, in relation to physiological and genetic manipulations.