TABLE 5.
Effect of metal ion addition on vanadium nitrogenase synthesis and activitya
| Metal ion (concn [μM]) | Parameter for nitrogen-fixing medium
|
Parameter for metal-depleted nitrogen-fixing medium
|
||
|---|---|---|---|---|
| Nitrogenase activity | C2H6/C2H4 ratio | Nitrogenase activity | C2H6/C2H4 ratio | |
| V (10) | 8.2 (1.1) | 0.019 | 5.9 (1.1) | 0.013 |
| V (100) | 9.2 (2.0) | 0.019 | ND | ND |
| V (10) and Mo (10) | 8.6 (0.9) | 0.021 | 3.7 (1.0) | 0.020 |
| V (10) and Mo (100) | 6.0 (1.1) | 0.021 | 4.8 (1.0) | 0.019 |
a
R. palustris strain CGA766 (ΔnifH nifD::Tn5 ΔanfA) was tested. Data are averages of three or more measurements, and standard deviations are shown in parentheses. ND, not determined.