FIG. 5.

The five TA systems do not enhance competitiveness in long-term stationary-phase cultures. The viability of individual cultures of the wild-type (WT) (open square) and the Δ5 (open triangle) strains (A) and of mixed cultures of the wild-type and Δ5 Nal^r (open circle) cultures (B) was measured daily for 7 days (see Materials and Methods). The graphs represent the averages from three independent experiments. The number of CFU/ml at each time point (dx) was normalized to that at day 1 (d₁) for each strain. Similar results were obtained with the symmetrical mixed culture of the wild-type Nal^r and Δ5 strains and with a mixed culture of wild-type and Δ5 yefM-yoeB::Kan strains (data not shown; see Materials and Methods).