抄録
Cells of Escherichia coli at the logarithmic phase of growth lost colony-forming ability when treated in 0.01M Tris buffer containing 0.15M sodium chloride and then diluted with 0.01M Tris buffer. The sodium chloride-treated cells did not lose colony-forming ability when they were diluted with 0.01M Tris buffer containing 0.15M sodium chloride. Furthermore, when the concentration of Tris buffer for dilution was raised to 0.15M, the decrease in survival was effectively prevented. Lysis of sodium chloride-treated cells was observed during incubation in 0.01M Tris buffer. This cell lysis was inhibited by the presence of Mg2+, Ca2+ or Mn2+ in the dilution buffer and also by incubation at 0°C. The cell lysis seemed to be unrelated to the loss of viability, since viability decreased rapidly when the sodium chloride-treated cells were diluted with 0.01M Tris buffer at 0°C, where the cell lysis was not observed. A polymyxin B resistant mutant was more sensitive to sodium chloride treatment but was more resistant to sucrose-osmotic shock than its parent strain. These results suggest that the saline sensitive phenomenon involves osmotic shock of the sodium chloride-treated cells. Thus, we called this phenomenon sodium chloride-osmotic shock.
