Cross-Regulation between the phz1 and phz2 Operons Maintain a Balanced Level of Phenazine Biosynthesis in Pseudomonas aeruginosa PAO1
Fig 5
Translational fusion constructs pME15Z1 (phz1′-′lacZ) and pME15Z2 ((phz2′-′lacZ) generated to study regulation between two phenazine-producing loci.
(A) β-Galactosidase activities were produced by pME15Z1 in the double-deletion mutant Δphz1phz2 (solid circle), the single-deletion mutant Δphz1 (solid square), Δphz2 (solid triangle), and in the wild-type PAO1 (solid diamond). pME6015 in mutant Δphz1 (open square) served as the negative control. (B) β-Galactosidase activities were produced by pME15Z2 in the Δphz1phz2 mutant (solid circle), the Δphz1 mutant (solid square), the Δphz2 mutant (solid triangle), and the wild-type PAO1 (solid diamond). pME6015 in the single-deletion mutant Δphz2 (open triangle) served as the negative control. All experiments were performed in triplicate, and each value was presented as the average ± standard deviation.