FIG 6.
Overexpression of RpoN suppresses mucoidy through interference with PalgD but not PalgU in P. aeruginosa PAO581. (A) Image of PAO581 carrying empty vector pHERD20T and pHERD20T-rpoN grown on a PIA plate with carbenicillin and 0.1% arabinose at 37°C for 24 h. (B) The β-galactosidase activity of PalgU and of (C) PalgD using PalgU-lacZ and PalgD-lacZ reporter system shuttled in the chromosome of PAO581 via mini-CTX. These two strains were introduced pHERD20T (control) and pHERD20T-rpoN. Strains were grown on PIA plates with tetracycline, carbenicillin, and various concentrations of arabinose (0.05%, 0.1%, and 0.5%) at 37°C for 24 h. Values shown are mean relative expression ± standard deviation from triplicate reads. One-way ANOVA was used with statistical significance at P < 0.01.