FIG 4.

Gallein phenocopies ppk deletion to reduce production of toxic P. aeruginosa pigment molecules. (A) Effects of gallein treatment and ppk gene deletion on pyoverdine production. The top panel shows a photograph of representative cultures, and the bottom panel shows pyoverdine quantification via absorbance at 403 nm. (B) Effects of gallein treatment and ppk gene deletion on pyocyanin production. The top panel shows a photograph of representative pyocyanin extracts, and the bottom panel shows pyocyanin quantification via absorbance at 520 nm following chloroform extraction and HCl treatment. ns, P > 0.05; *, P < 0.05; **, P < 0.01; ***, P < 0.001 (two-way ANOVA, Tukey’s multiple-comparison test, n = 3). All data points are the average from triplicates; error bars are ±standard deviation.