TABLE 2.
Expression of glnK-lacZ fusion in P. putida and E. coli
| Fusion plasmid | Structure | Strain | Other plasmid | β-Galactosidase activitya (Miller units ± SD)
|
|
|---|---|---|---|---|---|
| Nitrogen excess | Nitrogen limitation | ||||
| P. putida | |||||
| pMPO313 | glnK-lacZ | KT2442 | 1,167 ± 166 | 33,204 ± 4,453 | |
| pMPO234 | Empty vector | KT2442 | 177 ± 22 | 153 ± 19 | |
| pMPO313 | glnK-lacZ | MPO201 (NtrC−) | 908 ± 126 | 1,477 ± 90 | |
| pMPO234 | Empty vector | MPO201 (NtrC−) | 192 ± 31 | 152 ± 12 | |
| E. coli | |||||
| pMPO313 | glnK-lacZ | ET8000 | 130 ± 35 | 13,783 ± 1,774 | |
| pMPO234 | Empty vector | ET8000 | 741 ± 178 | 1,024 ± 260 | |
| pMPO313 | glnK-lacZ | ET8556 (NtrC−) | pMPO243 (ntrC) | 259 ± 31 | 8,474 ± 201 |
| pMPO234 | Empty vector | ET8556 (NtrC−) | pMPO243 (ntrC) | 535 ± 48 | 626 ± 70 |
| pMPO313 | glnK-lacZ | ET8556 (NtrC−) | pMPO310 [ntrC(D55E,S161F)] | 10,087 ± 1,714 | 10,212 ± 678 |
| pMPO234 | Empty vector | ET8556 (NtrC−) | pMPO310 [ntrC(D55E,S161F)] | 755 ± 101 | 754 ± 139 |
| pMPO313 | glnK-lacZ | ET8556 (NtrC−) | 189 ± 17 | 469 ± 68 | |
| pMPO234 | Empty vector | ET8556 (NtrC−) | 875 ± 148 | 1,637 ± 205 | |
a
For P. putida, serine was the nitrogen source, and for E. coli, glutamine was the nitrogen source under nitrogen-limited conditions (see Materials and Methods).