Figure 4

Growth and chromate reduction kinetics of S. oneidensis MR-1 wild type and the Δ so2426 mutant. (A) Wild-type (●) and mutant (○) cultures were cultivated in LB broth without the addition of chromate under aerobic conditions and compared to wild-type (▼) and mutant (△) cultures grown in LB broth amended with a final K₂CrO₄ concentration of 0.3 mM. (B) Cr(VI) removal rates for the S. oneidensis MR-1 (●), Δso2426 (○), and complemented Δso2426(so2426⁺) (▼) strains in LB broth supplemented with 0.3 mM chromate. The different cultures were challenged with 0.3 mM K₂CrO₄ when cells reached an OD₆₀₀ of 0.5 (mid-log point). The error bars indicate standard deviations of triplicate measurements.