Ion Metabolism in a Halobacterium I. Influence of age of culture on intraceUular concentrations

Work is described on the changes in cell ions during growth of cultures of a species of Halobacterium isolated from the Dead Sea. Cell K concentration fell from 5.5 to 3.8 moles per kg cell water during the logarithmic phase of growth and maintained the latter value during the stationary phase (initial medium concentration, 7 re_M). Cell Na and CI followed a complex series of roughly parallel changes. The logarithmic phase ion concentrations were: Na, 1.0-2.3 moles/kg cell water; CI, 2.3-3.7 moles/kg cell water. The final stationary phase values were: Na, 0.5 moles/kg cell water; CI, 2.3-2.9 moles/kg cell water (medium NaC1 concentration, 3.9 Molal). It is suggested that most of the K + is bound within the cytoplasm.