Figure 8.

Sensitivity of E.coli strains to nitrous acid. Escherichia coli cells proficient and deficient in AlkA (encoded by the alkA gene) or Endo VIII (encoded by the nei gene) were treated with the indicated concentrations of NaNO₂ in acetate buffer (pH 4.6) and the survival fractions were determined as described in Materials and Methods. Open circles, MV1161 (wild type); closed circles, MV1571 (alkA); open triangles, KY100 (nei); closed triangles, KY101 (alkA nei). The data are averages of three independent experiments. Standard deviations are indicated with error bars.