Interaction of cadmium and calcium on ethanol fermentation by Saccharomyces cerevisiae

In this study, the effect of cadmium on ethanol fermentation with different glucose concentration was investigated. The presence of cadmium inhibited cell growth and ethanol fermentation, especially in the cases of high concentrations of glucose. Under cadmium stress, glutathione (GSH) concentrations in broth and cell increased, suggesting that cadmium stimulated GSH synthesis. Due to cadmium stress, the inhibitory effect of an initial concentration of glucose became more serious, and a high concentration of ethanol could not be obtained by increasing the glucose concentration. Calcium could alleviate cadmium toxicity even at high glucose concentrations. The assay of cadmium and GSH in broth and cell demonstrated that calcium could hinder the transport of cadmium into cells. The utilization of calcium could provide a much higher productivity of ethanol with higher ethanol concentration, indicating the important role of calcium in bioconversion of cadmium-containing biomass into ethanol.