FIG 3.

Impact of acidified NaNO₂ on the growth of S. Typhimurium WT pBR322, the ΔcadA pBR322 mutant, and the complemented strain (ΔcadA-comp). (A) Representative growth curves (recorded in a Bioscreen C system at 24°C) of S. Typhimurium WT pBR322 (filled diamonds), the ΔcadA pBR322 mutant (shaded squares), and the ΔcadA-comp strain (shaded triangles) in LB (pH 5.5) plus 150 mg/liter ampicillin in the absence or presence of NaNO₂ at 50 mg/liter, 100 mg/liter, or 150 mg/liter. (B) Time required for each strain to reach an OD₆₀₀ of 0.6 (half-maximum OD₆₀₀) plotted against the NaNO₂ concentration. The data are means and standard deviations for three independent experiments including duplicates.