EFFECT OF POTASSIUM VERSUS SODIUM IN THE SPORULATION OF SACCHAROMYCES

Abstract

Slight modifications have been made in the sodium acetate-glucose medium of Adams which have significantly increased yields of asci in several strains of Saccharomyces. KC1 and MgSO4, when added in certain concentrations to sodium acetate-yeast extract-glucose medium, have more than doubled the yields of asci in most cultures of yeasts tested. Potassium acetate may be substituted for sodium acetate in the sporulation medium with correspondingly high results. Although considerable sporulation occurred in Adams'' sodium acetate-glucose medium, it was increased significantly by the addition of Mg, K, and yeast extract. The large amount of debris in the absence of yeast extract and the increased sporulation in its presence may indicate the necessity of exogenous sources of nutrients in the sporulation phase, other than acetate, regardless of the nutritional characteristics of the presporulation phase. Practical applications of this medium solidified with agar have been suggested.