FIG. 5.

Growth curves of S. mutans UA159 (•), ΔspxA (▪), ΔspxB (○), and ΔspxAB (□) strains under oxidative stress conditions. Exponentially grown cultures were inoculated in BHI medium containing 0.5 mM H₂O₂ (A) or 0.25 mM diamide (B), and growth at 37°C was monitored using the Bioscreen C growth reader. The curves shown are representative of a typical experiment performed at least five times.