Fig. 5

Percent survival of S. mutans post-treatment with 5 mM H₂O₂. Cells from t = 4 (a), t = 8 (b), or t = 16 (c) hour simulated microgravity (triangles) and normal gravity (circles) HARV cultures (n = 3 independent experiments per time point per growth condition) were harvested by centrifugation and resuspended in sterile HBSS. Samples were withdrawn to determine initial CFU/ml (“t = 0”), and then H₂O₂ was added to a final concentration of 5 mM. CFU/ml of each cell suspension was sampled at 20, 40, 60, 90, and 120 min post-H₂O₂ addition, and CFU/ml were determined. % Survival was calculated by 100 × [(t = final CFU/ml)/(t = 0 CFU/ml)]. Error bars = SEM. Asterisk denotes statistical significance, one-tailed t test (p < 0.05)