TABLE 2.

Effect of inducers on transcription of the fhp promotera

Condition and strain (genotype)bβ-Galactosidase activity (Miller U)
NoneNitrate (20 mM)Nitrite (5 mM)SNP (3 mM)GSNO (3 mM)NOc (30 μM)
Aerobic
    PAO1 (wild type)168 ± 5.6257 ± 38243 ± 51601 ± 248816 ± 31ND
Oxygen-limiting
    PAO1 (wild type)13 ± 112,159 ± 3642,707 ± 1941,631 ± 3771,246 ± 891,926 ± 69
    RM488 (nirS)10 ± 0.8ND585 ± 781,554 ± 215NDND
    RM495 (norCBD)44 ± 32ND1,488 ± 3432,599 ± 522NDND
    PFM4302 (fhpR)6.5 ± 4.5ND103 ± 1769 ± 22NDND
    RN102 (rpoN)58 ± 30ND81 ± 3087 ± 6.4NDND
    PAO6261 (anr)8.3 ± 6.9ND2,210 ± 3911,204 ± 70NDND
    RM536 (dnr)19 ± 17ND2,736 ± 8112,330 ± 377NDND
  • a Strains were grown under aerobic or oxygen-limiting conditions in synthetic medium supplemented with the indicated nitrogen oxide or NO-generating reagent. Values are means ± standard deviations from more than three independent cultures. ND, not determined.

  • b All strains carried pFH56 (fhp::lacZ).

  • c Gaseous NO was added by using a gastight syringe. Solute concentration was calculated from a published value (37).