TABLE 2.
Regulation of pyrG::lacLM fusion in L. lactis
| Strain | Genotype | Plasmid | Addition(s) to mediuma (μg/ml) | Td (min)b | β-Galactosidase activity (U/OD436 unit)c | Relative expression |
|---|---|---|---|---|---|---|
| CJ217 | cdd pyrG::lacLM | None | CR (20) | 56 ± 3 | 3.7 ± 1.4 | 1 |
| CR (20), UR (500) | 109 ± 7 | 55 ± 8 | 15 | |||
| CR (20), AR (100) | 110 ± 14 | 24 ± 5 | 6 | |||
| CR (20), CdR (500) | 151 ± 10 | 57 ± 1 | 15 | |||
| CJ298 | cdd pyrG::ISS1 | pCJ29 | CR (20) | 59 ± 4 | 71 ± 19 | 1 |
| CR (20), UR (500) | 119 ± 8 | 1,275 ± 98 | 18 | |||
| CR (20), AR (100) | 114 ± 10 | 380 ± 93 | 5 | |||
| CR (20), CdR (500) | 166 ± 8 | 1,150 ± 44 | 16 | |||
| CJ238 | cdd | pCJ29 | None | 60 ± 2 | 76 ± 8 | 1 |
| CR (20) | 58 ± 1 | 47 ± 6 | 0.62 | |||
| CR (50) | 59 ± 2 | 46 ± 5 | 0.60 | |||
| CR (500) | 59 ± 2 | 48 ± 5 | 0.63 | |||
| UR (50) | 59 ± 3 | 78 ± 9 | 1 | |||
| CJ233 | cdd | pAK80 | None | 57 ± 1 | <0.02 |
a
Abbreviations: CR, cytidine; UR, uridine; AR, adenosine; CdR, deoxycytidine. The nucleosides were added to exponentially growing cells at an OD436 of 0.2.
b
Td, doubling time GSA in defined medium. The data are averages and standard deviations from three to five independent experiments.
c
The cells were harvested at an OD436 of 0.8. The data are averages and standard deviations from three to five independent experiments.