FIG. 3.

BosR is required for optimal protection from H₂O₂. Two independent anaerobic cultures were grown to exponential phase and treated with various concentrations of H₂O₂ up to 50 mM each in triplicate. JH300 (open circles) is significantly more sensitive to killing by H₂O₂ relative to parental, ML23 (solid squares) with a P value across all H₂O₂ concentrations tested of less than 0.001. The lines shown represent the best fit to the logit regression model for the bosR mutant (JH300, top line) and the parental strain (ML23, bottom line) for the data obtained. Please note that the data points for the 1 mM H₂O₂ treatment are of equal value for both strains tested and thus overlap one another.