Magnesium as a stress-protectant for industrial strains of saccharomyces cerevisiae
During brewery fermentations, individual yeast cells may be confronted with a variety of environmental stresses that impair yeast growth and fermentative metabolism. An understanding of the stress physiology of industrial yeasts is therefore important in order to counteract deleterious effects of stress on fermentation and, ultimately, product quality. The present study describes the influence of magnesium ions in preventing cell death caused by temperature shock and ethanol toxicity in Saccharomyces cerevisiae yeast strains employed in brewing, distilling, and wine fermentations. Results obtained show that, by increasing the extracellular availability of magnesium ions, physiological protection may be conferred on temperature- and ethanol-stressed yeast cells with respect to culture viability and growth. This practical approach is envisaged to offer benefits to alcoholic fermentation processes in terms of enhancing the viability of the yeasts employed. It is proposed that magnesium prevents stress-induced damage to yeast cells by protecting the structural and functional integrity of the plasma membrane.