TABLE 3.
Regulation of GDH activity in the presence of alanine
| Strain | Relevant genotype | Growth mediuma | GDH sp actb |
|---|---|---|---|
| MK1 | Wild type | GNgln | 310 ± 25 |
| GN | 227 ± 15 | ||
| Ggln | 47 ± 6 | ||
| GNala | 47 ± 3 | ||
| KC2668 | dadA1 | GNgln | 417 ± 11 |
| GN gln ala | 332 ± 8 | ||
| GN ala pro | 51 ± 5 | ||
| Ggln | 27 ± 5 | ||
| KC3902 | dadA1, pCB515c | GN | 1,233 ± 232 |
| GNala | 185 ± 48 | ||
| KC2725 | dadA1 nac-203 | GN | 410 ± 49 |
| GNala | 365 ± 43 | ||
| KC2863d | dadA1 gdh-3 | GN | 1,244 ± 268 |
| GNala | 874 ± 102 |
a
Growth medium was W4 salts supplemented with 0.4% glucose (G), 0.2% (NH4)2SO4 (N), 0.2% l-alanine (ala), 0.2% proline (pro), and 0.04% l-glutamine (gln) as indicated.
b
Average and standard deviation of at least three independent assays.
c
pCB515 contains gdhA in multicopy (pSC101 origin of replication, four to five copies per cell [14]).
d
gdh-3 in a mutation that results in an approximate threefold increase in GDH activity when cells are grown in glucose-ammonium minimal medium.