FIG. 5.

Expression of nhaA is dependent on growth phase. The cells, harboring the nhaA′-′lacZ fusion on the chromosome in a wild-type (RK33Z) or ΔnhaR (NDZ1) background, were grown and Na⁺ induced for 1 h as described in Materials and Methods. The nhaA′-′lacZ expression of the exponential and stationary-phase cultures was monitored as β-galactosidase activity in Miller units as described in the legend to Fig. 2. The data from one representative experiment of five very similar independent repetitions are shown.