TABLE 1 .
Urease activity in H. pylori parent and mutant strains as a function of nickel added to the growth mediuma
| Strain | Urease activity at supplemental nickel concn (µM) of: |
|||
|---|---|---|---|---|
| 0 | 0.5 | 5 | 50 | |
| WT (26695) | 5 ± 1 | 31 ± 6 | 158 ± 22 (a) | 190 ± 15 (c) |
| Δmua | 6 ± 2 | 34 ± 7 | 195 ± 20 (a) | 358 ± 54 (c) |
| ΔnikR | 6 ± 2 | 28 ± 4 | 46 ± 5 (b) | 46 ± 10 |
| Δmua ΔnikR | 5 ± 1 | 31 ± 9 | 57 ± 6 (b) | 46 ± 4 |
a
Urease activity is expressed as micromoles of NH3 produced per minute per milligram of total protein. Results shown are the mean ± standard deviation of three to seven independent experiments. Like letters after standard deviation values indicate a significant difference between the two mean values based on Student’s t test (P < 0.01).