Determination of intracellular trehalose and glycogen in Saccharomyces cerevisiae.

A simple, sensitive and nonlaborious enzyme-based method has been developed for determination of both trehalose and glycogen in yeast cells. The method is based on extraction of trehalose and glycogen into a 40 mM acetate buffer (pH 4.8) by mechanical disintegration of the cells in a bead mill. Subsequently, trehalose and glycogen can be hydrolyzed to glucose by the enzymes trehalase and amyloglycosidase, respectively. The formed glucose is quantified by a flow injection analyzer based on the enzyme glucose oxidase. The method gives results comparable to traditional methods but the simplicity of the analysis results in a much lower relative standard deviation. The excellent sensitivity of the glucose analyzer means that as little as 1 microgram trehalose or glycogen can be determined which reduces the required sample volume. This makes the method ideal for physiological studies, e.g., of transients in continuous cultures of Saccharomyces cerevisiae. In addition, a consistent procedure has been derived for pretreatment and storage of samples.