FIG. 5.

Quantification of 3-oxo-C12-HSL. Cell extracts taken at the end of the liquid assay were analyzed using the biosensor strain pSB1075. Light produced in response to 3-oxo-C12-HSL was quantified. All values are the means from at least three independent experiments, with standard errors shown. Higher levels of 3-oxo-C12-HSL were detected in PAO1 ΔpvdQ compared to the PAO1 wild type. Both overexpression of the protein (IPTG induced) and external addition of the purified protein resulted in reduced 3-oxo-C12-HSL levels, correlating to the better survival of the worms under these conditions.