TABLE 4.
β-Galactosidase activities of Synechococcus sp. mutant strains CSLM40, CSLM26, CSLM27, and CSLM35 incubated with ammonium or nitratea
| Strain | Relevant genotype | β-Galactosidase (mU/mg of protein)
|
|
|---|---|---|---|
| Ammonium | Nitrate | ||
| CSLM40 | nir::lacZ-C.K3 | 113 (18) | 475 (90) |
| CSLM26 | moaA::lacZ-C.K3 | 110 (11) | 190 (40) |
| CSLM27 | moeA::lacZ-C.K3 | 106 (10) | 200 (31) |
| CSLM35 | moaC::lacZ-C.K3 | 116 (22) | 216 (19) |
a
Ammonium-grown cells were collected and transferred to media containing the indicated nitrogen source. After 14 h of incubation under culture conditions, total protein and β-galactosidase activity were measured. Data are the medians of four independent experiments (standard deviations are shown into parentheses).