Survival assay with hydrogen peroxide.

<p>The effect of H₂O₂ on bacterial viability was assayed by counting the colony-forming units after exposing the cultures to 500 μM of H₂O₂ for 3.5 hours, in enriched BHI broth at 37°C in anaerobic conditions. Broken lines represent the numeration of viable cells after H₂O₂ addition (500 μM) and solid lines represent the control condition without H₂O₂. Wild-type (■), <i>cydAB</i> mutant (▲) and complemented <i>cydAB</i> mutant (●). Bars represent standard errors.