FIG 5.

EepR is necessary for serratamolide and serratamolide-dependent phenotypes. (A) Hemolysis and swarming are EepR dependent in strain K904, but swimming is not. K904 ΔeepR mutant, CMS2904. (B) Swarming motility is defective in the ΔeepR (CMS2097) mutant and could be restored when the chromosomal eepR deletion allele was replaced by the wild-type eepR gene (CMS2921). (C) Hemolysis and swarming phenotypes of the ΔeepR mutant (CMS2097) can be rescued by induced expression of swrW on a plasmid (pswrW/pMQ367) but not by the vector control (pMQ125). (D) Means and standard deviations from surfactant radii around colonies on a swarming agar plate (n ≥ 5 independent isolates). WT, CMS376; swrW strain, CMS635; crp strain, CMS1687; crp swrW strain, CMS2281; eepR strain, CMS2097; crp eepR strain, CMS2701; crp eepS strain, CMS2395. (E) HPLC-MS analysis of serratamolide levels in supernatants from stationary-phase cultures. An asterisk indicates the serratamolide peak. WT, CMS376; pigP strain, CMS2096; eepR strain, CMS2097; swrW strain, CMS635).