TABLE 3.
Specific urease activity in cell lysates
| Medium | Culture time (h) | Urease sp act (mU/mg)a |
|||||
|---|---|---|---|---|---|---|---|
| Without fumarate |
With 100 mM fumarate |
||||||
| SA113 | Δsdh | Fold difference, Δsdh vs SA113 | SA113 | Δsdh | Fold difference, Δsdh vs SA113 | ||
| TSB | 3 | 1.8 ± 0.8 | 3.7 ± 1.9 | 2.2 ± 0.8 | 1.6 ± 0.7 | 2.9 ± 1.8 | 1.8 ± 0.4 |
| 5 | 2.4 ± 0.9 | 8.7 ± 1.6 | 4.0 ± 1.0 | 1.9 ± 0.4 | 5.5 ± 2.1 | 2.8 ± 0.6 | |
| 7 | 13.6 ± 7.3 | 50.4 ± 11.6 | 4.3 ± 1.7 | 9.9 ± 1.4 | 19.0 ± 6.8 | 1.9 ± 0.4 | |
| 9 | 14.5 ± 7.9 | 69.2 ± 16.1 | 5.3 ± 1.4* | 7.6 ± 1.3 | 20.5 ± 3.3 | 2.7 ± 0.1* | |
| 24 | 16.7 ± 8.8 | 59.6 ± 2.5 | 4.2 ± 1.7* | 7.4 ± 1.6 | 15.3 ± 2.2 | 2.1 ± 0.2* | |
| CDM | 7 | 5.4 ± 1.2 | 7.7 ± 1.5 | 1.5 ± 0.6 | 2.5 ± 0.9 | 3.5 ± 0.4 | 1.5 ± 0.4 |
| 9 | 6.2 ± 1.6 | 9.1 ± 0.7 | 1.5 ± 0.3 | 2.9 ± 1.0 | 3.7 ± 0.9 | 1.3 ± 0.1 | |
| 24 | 3.3 ± 0.6 | 8.6 ± 0.7 | 2.7 ± 0.3** | 6.8 ± 1.9 | 4.9 ± 0.8 | 0.7 ± 0.1** | |
a
Specific urease activities (with 1 U defined as 1 μmol NH4+ min−1 mg of protein−1) were determined in cell lysates from cultures grown in TSB and CDM either with or without addition of 100 mM fumarate. Values are the averages of three independent experiments ± standard deviations. *, P < 0.1; **, P < 0.05 (urease activity ratio of cells cultivated in medium without fumarate versus activity ratio of cells cultivated in medium with 100 mM fumarate added).