TABLE 3.
Diazotrophic growth and whole-cell nitrogenase activity in liquid media
| Isolate | Addition to −Mo, −N BM | Generation time (h) | Nitrogenase activity ± SD (n)a
|
|
|---|---|---|---|---|
| nmoles C2H4·mg protein−1·30 min−1 | nmoles C2H6·mg protein−1·30 min−1 | |||
| A. vinelandii CA | NH4+ (28 mM) | 2.83 | − | − |
| Na2MoO4 (1 μΜ) | 3.49 | 2,542 ± 27 (2) | − | |
| V2O5 (1 μM) | 5.20 | 255 ± 28 (2) | 6 ± 1 (2) | |
| None | 5.92 | 66 ± 1 (2) | 5 ± 1 (2) | |
| ARB3 | NH4+ (10 mM) | 2.4 | − | − |
| Na2MoO4 (1 μΜ) | 1.8 | 672 ± 52 (2) | − (2) | |
| V2O5 (1 μM) | 3 | 100 | 6 | |
| None | 24 | 24 | 4 | |
| BR5 | NH4+ (10 mM) | 3.0 | 8 | − |
| Na2MoO4 (1 μΜ) | 3.1 | 1,328 | − | |
| V2O5 (1 μM) | 4.5 | 31 | 2 | |
| None | 5.3 | 15 | 3 | |
| BR6 | NH4+ (10 mM) | 2.3 | 7 ± 1.0 (2) | − (2) |
| Na2MoO4 (1 μΜ) | 2.7 | 1,277 | − (2) | |
| V2O5 (1 μM) | 8.6 | 40 ± 4 (2) | 3 ± 0.2 (2) | |
| None | 8.4 | 27 ± 15 (2) | 4 ± 1 (2) | |
| BR7 | NH4+ (10 mM) | 4 | − | − |
| Na2MoO4 (1 μΜ) | 4.3 | 1,293 ± 302 (2) | − (2) | |
| V2O5 (1μM) | 3.7 | 65 ± 29 (3) | 4 ± 0.4 (3) | |
| None | 4.9 | 30 ± 11 (3) | 4 ± 1 (3) | |
| BR8 | NH4+ (10 mM) | 2.5 | 36 ± 4 (2) | NDb |
| Na2MoO4 (1 μΜ) | 2.4 | 1,369 ± 55 (2) | ND | |
| V2O5 (1 μM) | 3.5 | 794 | 16 | |
| None | 3.5 | 89 ± 10 (2) | 5 ± 2 (2) | |
| BR10 | NH4+ (10 mM) | 1.1 | − | ND |
| Na2MoO4 (1 μΜ) | 2.3 | 1,616 ± 97 (2) | ND | |
| V2O5 (1 μM) | 2.5 | 781 | 25 | |
| None | ND | 320 | 14 | |
| DP6 | NH4+ (10 mM) | 4.7 | − | ND |
| Na2MoO4 (1 μΜ) | 3.6 | 1,324 ± 13 (2) | ND | |
| V2O5 (1 μM) | 3.7 | 136 ± 7 (2) | ND | |
| None | 4.0 | 67 ± 7 (2) | ND | |
| DP7 | NH4+ (10 mM) | 4.0 | − | ND |
| Na2MoO4 (1 μΜ) | 3.4 | 836 ± 134 (2) | ND | |
| V2O5 (1 μM) | 3.8 | 61 ± 36 (2) | ND | |
| None | 3.7 | 42 ± 7 (2) | ND | |
| MB4 | NH4+ (10 mM) | 4.8 | − | − |
| Na2MoO4 (1 μΜ) | 4.6 | 900 ± 319 (3) | − | |
| V2O5 (1 μM) | 4 | 52 ± 7 (2) | 5 ± 1 (2) | |
| None | 20.4 | 18 ± 2 | − | |
| MU4 | NH4+ (10 mM) | 3.7 | 42 ± 34 (2) | ND |
| Na2MoO4 (1 μΜ) | 4.8 | 481 ± 19 (2) | ND | |
| V2O5 (1 μM) | 6.1 | 352 ± 89 (2) | 10 ± 2 (2) | |
| None | 7.0 | 234 | 8 | |
| MU5 | NH4+ (10 mM) | 4.1 | 50 ± 10 (2) | ND |
| Na2MoO4 (1 μΜ) | 4.7 | 310 ± 9 (2) | ND | |
| V2O5 (1 μM) | 7.4 | 45 ± 2 (2) | ND | |
| None | 9.4 | 138 ± 6 (2) | ND | |
| MU6 | NH4+ (10 mM) | 1.2 | − (3) | − (3) |
| Na2MoO4 (1 μΜ) | 1.5 | 1,513 ± 636 (3) | − (3) | |
| V2O5 (1 μM) | 2.7 | 84 ± 33 (2) | 5 ± 2 (2) | |
| None | 2.4 | 24 | 4 | |
| MU11 | NH4+ (10 mM) | 2.5 | − | − |
| Na2MoO4 (1 μΜ) | 2.6 | 1,355 | − | |
| V2O5 (1 μM) | 3.1 | 92 ± 19 (2) | 4 ± 1 (2) | |
| None | 5.4 | 18 ± 9 (2) | 3 ± 1 (2) | |
| MU13 | NH4+ (10 mM) | 2.6 | − | − |
| Na2MoO4 (1 μΜ) | 2.9 | 865 | − | |
| V2O5 (1 μM) | 4.3 | 32 | 3 | |
| None | 4.8 | 16 | 3 | |
| NC2 | NH4+ (10 mM) | 1.9 | − | ND |
| Na2MoO4 (1 μΜ) | 2.3 | 2,841 ± 17 (2) | ND | |
| V2O5 (1 μM) | 2.7 | 431 ± 3 (2) | ND | |
| None | 3.1 | 123 ± 1 (2) | ND | |
| PB3 | NH4+ (10 mM) | 2.4 | − | ND |
| Na2MoO4 (1 μΜ) | 2.3 | 1,142 ± 34 (2) | ND | |
| V2O5 (1 μM) | 3.5 | 1,575 | 30 | |
| None | 11.1 | 693 | 43 | |
| PRM1 | NH4+ (10 mM) | 2.5 | 85 ± 10 (2) | ND |
| Na2MoO4 (1 μΜ) | 2.5 | 1,877 ± 338 (2) | ND | |
| V2O5 (1 μM) | 3.2 | 656 ± 39 (2) | ND | |
| None | 2.9 | 196 ± 18 (2) | ND | |
a
−, measured activity was no greater than activity of the blank (−Mo, −N BM); n, number of acetylene reduction assays on different days.
b
ND, not determined.