Effect of RpfF
on AHL synthase gene cepI expression. (A) The β-galactosidase activity of a cepI-lacZ transcriptional fusion in H111 wild-type (■), ∆rpfFBc (▲) and ∆rpfFBc supplemented with BDSF signal (◆). (B) Western blotting assay of CepI protein level. The data presented are the means of three replicates and error bars represents the standard deviation.