Fig. 5
Measurement of extracellular pyruvate during growth of S. mutans wild-type strain in FMC medium supplemented by different concentrations of extracellular pyruvate. The S. mutans UA159 wild type strain was grown in a low-glucose (11 mM) FMC medium supplemented by 1 (a), 5 (b), 10 (c), and 40 mM (d) pyruvate (pyr). For time course measurements of extracellular pyruvate and growth, samples were taken at 1 or 2 h intervals (see Materials and Methods for details). The concentration of pyruvate was determined using an EnzyChrom™ pyruvate assay kit, and growth was measured by the optical density at 600 nm (OD600). Bars indicate the concentration of extracellular pyruvate; solid line with circles indicates growth curve. The results are representative of two independent experiments