Figure 2. Effects of different carbon sources on monoculture growth and competitive index of a prfA* mutant.

(A) Growth curves of the wild type and prfA G145S L. monocytogenes strains in buffered LB (pH 7.4) with and without 55 mM of either glucose (glu) or glycerol (gly) at 37°C with shaking were determined by measuring CFU/mL at the specified time points. Each growth curve is representative of two independent experiments. (B) The wild type cam^R strain was mixed with the chloramphenicol-sensitive prfA G145S mutant in buffered LB with and without 55 mM of either glucose (glu) or glycerol (gly) at 37°C with shaking. Mixed cultures were subjected to repeated cycles of growth and dilution (1∶100) into fresh media every 24 hours. CI values were determined immediately prior to each dilution. The data represent the means ± standard errors of three independent experiments.