X-RAY-MICROANALYSIS OF INTRACELLULAR IONS IN THE ANAEROBIC HALOPHILICEUBACTERIUM HALOANAEROBIUM PRAEVALENS

The intracellular concentrations of Na+, K+, and Cl- of the anaerobic halophilic eubacterium Haloanaerobium praevalens were assayed by means of X-ray microanalysis with the transmission electron microscope. App arent intracellular cation concentrations between 1.22 and 1.91 M and chloride concentrations of 0.93 -1.57 M were measured in cells growing exponentially in 2.6 M total salts. In exponentially growing cells, K + was the major cation (70% of the cation sum). Stationary phase cells showed a high variability among individual cells, some of the cells c ontaining higher Na+ than K+ concentrations.