TABLE 2.
Regulation of d-amino acid dehydrogenase and alanine racemase activities in K. aerogenes
| Strain | Relevant genotype | Growth mediuma | Sp actb
|
|
|---|---|---|---|---|
| d-Amino acid dehydrogenase | Alanine racemase | |||
| MK1 | Wild type | GN | 13 ± 3 | 22 ± 10 |
| GNala | 386 ± 162 | 428 ± 100 | ||
| Gala | 331 ± 32 | 415 ± 70 | ||
| Alac | 769 ± 62 | 615 ± 36 | ||
| KC2725 | dadA1 nac-203 | GNala | 14 ± 3 | 228 ± 30 |
| KC2001 | ntrC5 | GN | 10 ± 4 | ND |
| GNala | 240 ± 7 | ND | ||
| MK9682 | ntr-45 | GNglnd | 42 ± 6 | ND |
| GNglnalad | 629 ± 70 | ND | ||
| KC3346 | wild type | GN | 7 ± 1 | ND |
| GNala | 356 ± 59 | ND | ||
| KC3345 | nac-203 | GN | 14 ± 3 | ND |
| GNala | 206 ± 18 | ND | ||
| KC3847 | pPC36e | GN | 10 ± 4 | ND |
| GNIPTG | 52 ± 11 | ND | ||
| KC4469 | crp | GNala | 262 ± 38 | ND |
| Alac | 336 ± 98 | ND | ||
a
Growth medium was W4 salts supplemented with 0.4% glucose (G), 0.2% (NH4)2SO4 (N), 0.2% l-alanine (ala), 0.2% l-glutamine (gln), and 1 mM IPTG (to induce nac expression from the tac promoter [pPC36]) as indicated.
b
Average and standard deviation of at least three independent assays. ND, not determined.
c
0.4% l-alanine.
d
0.2% l-glutamine added to supply glutamate (MK9682 is a glutamate auxotroph).
e
Contains nac driven by the IPTG-inducible tac promoter.