FIG. 1.

6S RNA-deficient cells survive at elevated pH better than wild-type cells. (A) Wild-type (ZK126) (gray line) or ssrS1 (KW437) (black dashed line) cells were inoculated into LB pH 9.3 medium and grown at 37°C. At the times indicated, cell densities were determined by plating. The data shown are from one representative experiment containing five duplicate cultures per strain. (B) Wild-type (KW72) or ssrS1 (GS075) cells containing pKK-6S(M5)* (shaded bars) or pKK-6S* (solid bars) were inoculated into LB pH 9.3 medium and grown at 37°C for 48 h. Cell densities were measured by plating. The data shown are averages from two representative experiments with two duplicates for each experiment. Similar results were obtained in at least four independent experiments. Error bars, standard deviations from the averages. At several time points in panel A, the error bars are smaller than the symbols and therefore are not visible.