TABLE 5.
β-Galactosidase expression of an nrgAB-lacZ fusion in wild-type and ccpA mutant strains
| Relevant genotypea | Carbon source(s) | Value for cells grown with nitrogen sourceb:
|
|||
|---|---|---|---|---|---|
| Glutamine
|
Glutamate
|
||||
| Doubling time (min) | β-Galactosidase sp act (U/mg of protein) | Doubling time (min) | β-Galactosidase sp act (U/mg of protein) | ||
| Wild type | Glucose | 53 | 0.04 | 165 | 288 |
| Glucose + lactate | 55 | 0.06 | 180 | 310 | |
| ccpA | Glucose | 86 | 0.04 | 155 | 0.5 |
| Glucose + lactate | 85 | 0.05 | 195 | 399 | |
a
All strains were derivatives of 168 and contained the (nrgA-lacZ)407 fusion.
b
β-Galactosidase levels are the averages of three or more determinations, which did not vary by more than 25%. Cultures were grown in MOPS minimal medium containing the indicated carbon and nitrogen sources.