TABLE 2.
Nitrogenase activity in R. rubrum glnD mutants
| Strain | Chromosomal genotype | Plasmids and genes | Nitrogenase activitya (units) |
|---|---|---|---|
| UR2 | Wild type | None | 800 |
| UR1111 | glnD1::aacC1 (opposite orientation) | None | <20 |
| UR1119 | glnD2::aacC1 (same orientation) | None | 750 |
| UR1120 | glnD1::aacC1 (opposite) | pCK3 (K. pneumoniae nifA) | 800 |
| UR1144 | glnD1::aacC1 (opposite) | pUX1097 (glnD+) | 600 |
| UR1155 | glnD1::aacC1 (opposite) | pUX1102 (glnD1::aacC1) | 400 |
| UR1156 | glnD1::aacC1 (opposite) | pUX1103 (glnD2::aacC1) | 420 |
| UR1157 | glnD1::aacC1 (opposite) | pUX1105 (3′ region of glnD′) | <20 |
| UR1242 | glnD1::aacC1 (opposite) | pUX1224 (5′ region of glnD′) | 800 |
| UR1325 | ΔglnD3::aacC1 (opposite orientation) | None | <20 |
| UR1326 | ΔglnD4::aacC1 (same orientation) | None | <20 |
| UR1330 | ΔglnD3::aacC1 (opposite) | pCK3 (K. pneumoniae nifA) | 620 |
| UR1331 | ΔglnD4::aacC1 (same) | pCK3 (K. pneumoniae nifA) | 650 |
| UR1332 | ΔglnD3::aacC1 (opposite) | pUX1224 (5′ region of glnD) | 700 |
| UR1333 | ΔglnD4::aacC1 (same) | pUX1224 (5′ region of glnD) | 670 |
a
Nitrogenase activity was derepressed in MG under illumination. Each unit of nitrogenase activity is expressed as nanomoles of ethylene produced per hour per milliliter of cells at an optical density at 600 nm of 1. Each activity value is from at least 10 replicate assays from different individually grown cultures. The standard deviation is about 10 to 15%.