FIG. 3.

The five TA systems are not involved in the growth inhibition mediated by an acidic shock and do not advantage poststress recovery. Cultures of the wild-type (WT) (square) and Δ5 (triangle) strains were shifted from pH 6.8 to pH 4 medium (see Materials and Methods). The viability of treated (open symbols) and untreated (filled symbols) cells was measured for 120 min (A). After 120 min, the wild-type and Δ5 cultures were shifted back to pH 6.8. Viability was measured for 120 min (until early stationary phase) (B). The number of CFU/ml at each time point (tx) was normalized to that at time zero (t₀) for each strain. The graphs represent the averages from three independent experiments.