FIG. 2.

Initial rates of hydrogen peroxide production by S. gordonii CH1 in 1 mM glucose and selected concentrations of potassium l-lactate and potassium acetate. Cells were grown and initial rates of hydrogen peroxide synthesis were measured as described in Materials and Methods and in the legend to Fig. 1. Results are means ± SD of three rate determinations at each concentration point, and asterisks denote the level of statistical significance between data for equal concentrations of potassium l-lactate and potassium acetate (∗, P < 0.05; ∗∗, P < 0.005).