TABLE 2.
Expression of chromosomally integrated fixR′-′lacZ fusions in B. japonicum regR and regS mutants
| Strain | Relevant genotype | β-Galactosidase activity (Miller U [mean ± SE])a
|
|
|---|---|---|---|
| Aerobic | Anaerobic | ||
| 110spc4 | Wild type | 1 ± 1 | 1 ± 1 |
| 7276B | fixR′-′lacZ | 246 ± 12 | 958 ± 63 |
| 7277C | fixR′-′lacZ ΔUAS | 11 ± 2 | 511 ± 43 |
| 2408R | fixR′-′lacZ regS::Ω | 270 ± 48 | 775 ± 100 |
| 2409R | fixR′-′lacZ regS::Ω | 170 ± 14 | 850 ± 144 |
| 2426R | fixR′-′lacZ regR::Ω | 3 ± 1 | 98 ± 36 |
| 2427R | fixR′-′lacZ regR::Ω | 1 ± 1 | 81 ± 14 |
a
Numbers are the mean values ± standard errors of at least three independent experiments. In each experiment at least two cultures of all strains were grown in parallel and assayed in duplicate. Bacteria were grown to mid exponential phase, i.e., for 2 days in PSY medium supplemented with 0.1% (wt/vol) arabinose in the case of aerobic cultures and for 6 days in YEM medium plus KNO3 in the case of anaerobic cultures.