Figure 5.

The effect of the down-regulating walR on the cidA promoter activity using cidA promoter-lux reporter fusion. The Pspac-regulated walR mutant carrying cidA promoter-lux reporter was grown in TSB in the presence of different concentrations of IPTG (solid square: 1 mM; open circle: 10 μM) at 37°C with shaking. Both bioluminescence signals and cell growth were monitored at different phases of growth at 37°C by measuring the light intensity with a Chiron luminometer and optical density at 600 nm (OD₆₀₀) with a SpectraMax plus Spectrophotometer. Relative Light Unit (RLU) was calculated with the bioluminescence intensity divided by the optical density in the same time of culture. The experiments were repeated at least three times.