TABLE 1.

Effect of low pH on growth of S. mutans UA140 wt and ciaH and ciaR mutants

StrainDoubling time (min)a in:% Reduction in growth rate (TH pH 6.4 vs TH)
THTH pH 6.4
UA14069.4 ± 5.186.7 ± 4.520
140ciaH74.5 ± 7.5119.5 ± 3.560
140ciaR72.9 ± 6.988.5 ± 7.620
  • a Doubling time was calculated based on the formulas ln Z − ln Z0 = k(tt0), where k is the growth rate, and g = 0.693/k, where g is the doubling time. Values are the mean ± standard deviation obtained from three independent experiments.