FIG. 3.

Survival rates of S. mutans Xc24R cells grown in the presence of sucrose or glucose. S. mutans cells were grown in brain heart infusion broth until an optical density at 550 nm of about 0.4 was attained. The broth was sonicated three times for 10 s at 20% pulse power with a sonicator (Cell Disrupter model W-225R; Heat Systems, Inc., Farmingdale, N.Y.) and spread on tryptic soy agar supplemented with 0 to 5% (wt/vol) sucrose or 5% (wt/vol) glucose. The survival rates for cells grown at each concentration of added sucrose or glucose were calculated by dividing the number of CFU by the number of CFU for cells grown on medium without additional glucose or sucrose. Each column and bar represents the mean percent survival ± standard deviation for four different experiments. The statistical differences in survival rates were analyzed by using the Mann-Whitney U test. ∗, P < 0.05 (compared to survival rate of cells grown in the presence of 5% glucose).