FIGURE 5.

Extracellular complementation assay of ΔpapR cells with conditioned medium from ΔcodY compared to wild-type cells. The culture supernatant of ΔcodY, ΔpapR and wild-type cells was filter-sterilized before being used to resuspend ΔpapR cell pellets. The latter harbor a chromosomal transcriptional fusion between the promoter of plcA and lacZ. Cells were grown in LB at 37°C. All samples were collected 0.5 h after entry into stationary phase. β-galactosidase production was assayed after resuming growth for 1.5 h. The results are the mean values of two independent experiments, and the error bars represent standard deviation.