Fig. 7.

LacZ activity of aatJ-lacZ in wild-type P. aeruginosa PAO1 (a), the ΔaauR mutant (b) and the rpoN::Ω-Km mutant (c). Bacteria were grown in alanine-minimal media to an OD₆₀₀ of ~ 0.2 and then challenged with 20 mM of indicated substrate. LacZ activity was subsequently measured at 1.0 and 3.0 h post addition of substrate and is reported in Miller Units (MU). Data points represent mean values (n = 3) ± SD. For each strain or mutant, an ANOVA was performed with a Dunnett’s post hoc test (α value, 0.05) to identify significant changes in the expression of aatJ-lacZ relative to the alanine-treated control. Significant differences (P < 0.0001) are indicated with asterisks