Role of Insoluble Glycogen in Ethanol Adaptation Mechanism of Saccharomyces italicus

Saccharomyces italicus has two pools of glycogen-one is the soluble pool and the remainder water insoluble linked with cell wall or β-glucans. Soluble pool of glycogen present is assigned to produce energy required for metabolic activities but the insoluble pool in the cell wall plays a special physiological role in providing the osmotolerance under ethanol stress conditions. S. italicus grown in the presence of 2-8% v/v ethanol exhibits exponential increase in insoluble glycogen content as a protective measure against the stress created across the plasma membrane by the action of ethanol. But ethanol concentration above 8%v/v reduces hydrophobic interactions thereby decreasing the insoluble glycogen content with increase in membrane permeability.