FIG 7.

Regulation of the nfs cluster expression in Pseudomonas sp. HYS. (A) Expression of a plasmid-encoded nfs′-′lacZ translational fusion in Pseudomonas sp. HYS was determined under low-iron (MKB medium) and high-iron (MKB supplemented with 30 μM FeSO₄) conditions. (B) Expression of a plasmid-encoded nfs′-′lacZ translational fusion and growth were determined in wild-type HYS (squares) (HYS/pBBR5Z-Pnfs) and in a ΔgacA mutant (circles) (ΔgacA/pBBR5Z-Pnfs). Open symbols, β-galactosidase activity; solid symbols, OD₆₀₀. Each value is the average from three different cultures ± standard deviation.