FIG. 1.

Increased sensitivity of the yhbO mutant to environmental stresses. Logarithmic-phase cultures of wild-type (squares) and yhbO-deficient (diamonds) cells were incubated for the indicated times, as described in the text, in the presence of 15 mM (filled symbols) or 50 mM (open symbols) H₂O₂ (A), at 50°C (filled symbols) or 53°C (open symbols) (B), under UV irradiation (C), at pH 2.5 (D), at pH 10.5 (E), or in the presence of 2.5 M NaCl (F), and viable cell counts were determined. Experiments were done three times, and the mean value ± standard error of the mean (SEM) was calculated.