Fig. 1

Bacterial growth rates. a Growth of S. mutans UA159 incubated in TV medium supplemented with 15 mM glucose (●) or L-ascorbate (■). b Growth of wild-type UA159 (★), ptxA ⁻ strain (●), ptxB ⁻ strain (▲), ptxAB ⁻ strain (■), CptxA ⁻ strain (○), CptxB ⁻ strain (△) and CptxAB ⁻ strain (□) incubated in TV medium supplemented with 15 mM L-ascorbate. Samples were all grown at 37 °C for more than 48 h under anaerobic conditions and monitored every 2 h at 600 nm (OD₆₀₀). The data presented here are the average of three independent experiments performed in triplicate