TABLE 3.
Dependence of glycerol kinase specific activity on growth medium and genetic background
| Strain | GlpR/GlpK phenotype | Avg sp act ± SD (U/mg)a on growth medium (no. determinations)
|
||
|---|---|---|---|---|
| Minimal glucose | Minimal glycerol | LB medium | ||
| KH11 | R−/K+ | 0.1 ± 0.2 (4) | 0.8 ± 0.4 (6) | 2.1 ± 0.6 (9) |
| KH12 | R−/Ki | 0.1 ± 0.1 (4) | 0.2 ± 0.1 (6) | 2.1 ± 0.9 (7) |
| KH15 | R−/Kr | 0 ± 0.02 (4) | 0.7 ± 0.1 (6) | 1.9 ± 0.6 (6) |
| KH37 | R−/Ki,r | 0 ± 0.1 (4) | 0.2 ± 0.1 (6) | 1.2 ± 0.3 (7) |
| MC4100 | R+/K+ | 0 ± 0.1 (5) | 1.1 ± 0.7 (8) | 0.1 ± 0.2 (7) |
| KH34 | R+/Ki | 0 ± 0.1 (5) | 0.2 ± 0.1 (7) | 0 ± 0.02 (3) |
| KH24 | R+/Kr | 0 ± 0.1 (5) | 1.3 ± 0.7 (7) | 0 ± 0.2 (3) |
| KH38 | R+/Ki,r | 0 ± 0.1 (4) | 0.1 ± 0.1 (5) | 0 ± 0.2 (4) |
| MG1655 | R+/K+ | 0 ± 0.04 (6) | 1.0 ± 0.2 (7) | 0 ± 0.1 (5) |
| KH58 | R+/Ki | 0 ± 0.1 (6) | 0.2 ± 0.1 (3) | 0 ± 0.1 (3) |
| KH59 | R+/Kr | 0 ± 0.1 (5) | 0.6 ± 0.3 (4) | 0 ± 0.04 (3) |
| KH61 | R+/Ki,r | 0 ± 0.04 (5) | 0.2 ± 0.1 (6) | 0 ± 0.02 (3) |
a
Specific activities were determined as described in Materials and Methods. Numbers in parenthesis indicate the number of independent determinations, and the uncertainties are shown as the sample standard deviation. The values shown were corrected by subtracting the apparent specific activities obtained for the respective ΔglpK strains: KH18, 0.3 ± 0.1 U/mg; KH10 and KH51, 0.2 ± 0.1 U/mg. The apparent specific activities obtained with the ΔgkpK strains are not dependent on the addition of glycerol to the enzyme assay; i.e., they are not glycerol kinase activity but reflect other sources of ADP that are measured by the coupled assay.