Effect of Variable Sugar Concentrations on Glycogen and Ethanol Content in Saccharomyces sp.

Abstract

Saccharomyces cerevisiae (MTCC-12) maintains two pools of glycogen, one soluble and the other cell wall bound insoluble glycogen. Effect of variable concentrations of sugar on the insoluble pool of glycogen linked to wall β-glucan component was found to be more significant than that observed for soluble pool of glycogen. The study revealed that cells exhibit exponential increase in the amount of insoluble glycogen with corresponding increase in sugar concentration from 2-10 % (w/v). Ethanol content as well as concentration of insoluble glycogen in yeast cells, which were grown in sucrose medium, shows higher values than in glucose medium. Parallel increase in glycogen and ethanol content indicates their correlation with each other. Exponential increase in insoluble glycogen content serves as a protective measure against ethanol stress created across the plasma membrane of yeast cell.