Figure 4. Effects of pH (A) and sucrose (B) on the expression of gtf genes. S. mutans MT8148 was cultured in BHI broth with 25 mM phosphate buffer (A) with or without 2% sucrose (B) at 37°C to an optical density of 0.2 at 550 nm. Data are expressed as means and standard deviations of triplicate experiments. Statistical differences (P < 0.05, ANOVA) between pH 5 (*), pH 6(#), and pH 7 () (A), and without sucrose (*) (B) are indicated.