Survival of wild-type and mutant cells during stationary phase. WT, RNase II−, RNase PH−, and RNase II− RNase PH− strains were continually grown in 50 mL M9/glucose media at either 31°C or 42°C. At regular time intervals, 2 mL of cultures were collected, two appropriate sequential dilutions of cells in duplicate were spread on LB plates, and viable cells (CFU) were determined after overnight incubation at 37°C. The data from one of the sequential dilutions at each time point are presented as a percentage in which the time point with the highest number of colonies was set at 100%. A representative experiment from those repeated six times is shown.
