Effects of Ca2+ signal on the activities of key enzymes and expression of related genes in yeast ethanol metabolism and mitochondrial function during high sugar fermentation

BACKGROUND During high sugar fermentation, yeast is mainly affected by high sugar stress in the early stage. It becomes jointly affected by high sugar and ethanol stress as ethanol accumulates during fermentation. Ca2+, as the second messenger of the cell, mediates various metabolic processes. In this study, the effects of the Ca2+ signal on the activities of key enzymes, expression of related genes of ethanol metabolism, and mitochondrial function were investigated. RESULTS The results showed a significant increase in the activities of enzymes related to ethanol metabolism in yeast cells under a high sugar environment. Ca2+ significantly promoted the activities of enzymes related to mitochondrial respiratory metabolism and regulated the carbon flow between ethanol metabolism and the tricarboxylic acid cycle. The high sugar environment affected the expression of genes related to carbon metabolism, while the addition of Ca2+ stabilized the expression of related genes. CONCLUSION Ca2+ signal participated in ethanol and mitochondrial metabolism and regulated the key enzymes and related gene expression to enhance the resistance of yeast to stress during high sugar fermentation. (c) 2024 Society of Chemical Industry.