FIG. 8.

Hydrogen peroxide sensitivities of the wild-type E. chrysanthemi 3937, pecS mutant A3953, indA mutant A3954, and the double indA-pecS mutant A3956. (A) Experiments were performed by incubating 3 × 10⁹ bacteria with 10 mM hydrogen peroxide for the times indicated and determining viable cells by serial dilution and plating on LB agar. Survival of the H₂O₂-treated cells was normalized to the number of CFU at the beginning of the challenge. (B) The same experiments were performed with bacteria preincubated with either H₂O₂ (500 μM) or paraquat (40 μM). The data presented were obtained with H₂O₂ preinduction, but similar results were obtained with paraquat preinduction (data not shown). The data represent one of three separate experiments which gave similar results.