High levels of copper retard the growth of Saccharomyces cerevisiae by altering cellular morphology and reducing its potential for ethanolic fermentation

Summary Previous research has shown that high levels of Cu 2+ inhibit the growth of yeast and induce sluggish fermentation, resulting in a decrease in alcohol production. Little data are available on the effects of copper on the cell morphology, especially the surface elasticity of Saccharomyces cerevisiae . This work investigated the effects of Cu 2+ (0.5, 1.0 and 1.5 m m ) on the growth, surface characteristics and elasticity of two strains of S. cerevisiae in a low sugar model synthetic medium. The results indicated that high levels of Cu 2+ retarded the growth rate of S. cerevisiae and reduced the utilisation of reducing sugars. Cells showed intercellular adhesion, became small and deformed, and the surface was uneven and rough after the adsorption of Cu 2+ . The Young's modulus also decreased with an increase in the concentration of Cu 2+ , indicating that the cells had softened. This study reveals the response mechanism of S. cerevisiae under copper stress by altering cellular morphology and mechanical properties.