Skip to main content
. Author manuscript; available in PMC: 2010 May 1.
Published in final edited form as: Mol Microbiol. 2009 Apr 14;72(4):905–917. doi: 10.1111/j.1365-2958.2009.06693.x

Fig. 2. S. mutans growth kinetics.

Fig. 2

A. Growth of S. mutans in the presence of sCSP. To artificially mimic the high CSP concentrations induced by stress, cells were diluted into media supplemented with increasing concentrations of sCSP or without (control) and grown for 16 h. Cultures responded to sCSP with a slower growth rate and lower growth yield proportional to the increase in sCSP concentration. To ensure the specificity of the phenotype, a peptide was synthesized with the same amino acid composition as S. mutans CSP but with the order randomized. The randomized peptide did not have any effect on S. mutans growth (not shown).

B. Growth of S. mutans wild-type (WT), ΔcomDE mutant and ΔcomX mutant in the absence (–) and presence (+) of 2 μM CSP pheromone. While eliminating ComDE restores both the growth rate and yield of the culture in the presence of sCSP, the ΔcomX mutant shows a defect in growth yield both in the absence and presence of sCSP. We infer from these data that the altered growth yield of the culture in the presence of sCSP is due to ComE-controlled genes.