Fig 7. SoxR activity in mutants of the reduction system of SoxR.

The E. coli strains carrying the chromosomal PsoxS::lacZ fusion, wt (BE1000), ΔrsxC (AG047), ΔrsxC ΔiscUA (AG066), ΔrsxC ΔsufABCDSE (AG067), ΔrseC (AG045), ΔrseC ΔiscUA (AG064) and ΔrseC ΔsufABCDSE (AG065) were grown overnight in LB and inoculated (1/100) in fresh LB medium. The cultures were grown at 37°C until exponential phase (OD₆₀₀ 0.2–0.4) (A-B). β-galactosidase activity was monitored and expressed as Miller units. The experiments were done in triplicate. The means and standard deviations are shown. The p-values have been determined to compare mutant strains versus the wt strain. Asterisks represent the statistical significance calculated using the Bonferroni method (** p<0.01; * p<0.05; ns p>0.05).