Phosphorus metabolism in growing cultures of Saccharomyces cerevisiae.

The inhibitory effects of radiation and chemicals on the cellular division proceses in yeast and Escherichia coli in the logarithmic phases of growth have been studied in this laboratory. An investigation of phosphorus metabolism was undertaken as part of a program to correlate metabolic changes accompanying the inhibition of cellular division. In order to devise satisfactory experimental conditions for determining the effects of division-inhibitors on the phosphorus compounds in rapidly-dividing yeast cells, it became necessary to know the phosphorus spectrum of normal growing cultures. However, the paucity of data on the phosphorus metabolism of rapidly-dividing yeast cells at various stages of growth made it imperative that this study be made since it is not unlikely that the phosphorus content(s) of a particular fraction(s) might vary during the logarithmic growth cycle. This implies that, although the cells tain a steady rate of growth and multiplication during the log phase, the concentrations of intermediary metabolites of other components of the cell need not be in steady state. This paper describes a method for the fractionation and pbosphorus analysis of normal yeast in various stages of growth and division.