TABLE 2.
H2-dependent and H2-independent activities in soluble extracts of wild-type and deletion mutant A. eutrophus strains
| Strain | SH subunit(s) | Activity (%) ofa:
|
|||
|---|---|---|---|---|---|
| Hydrogenase
|
Diaphorase (NADH-BV) | ||||
| H2-NAD | H2-BV | D2-H+ exchange | |||
| H16 | HoxFUYH | 87 | 79 | 91 | 68 |
| HF424(pGE15) | HoxFUYH | 100 | 100 | 100 | 100 |
| HF424 | None | 0 | <0.5 | <0.5 | 4 |
| HF424(pGE346) | HoxHY | 0 | 9 | 20 | 4 |
| HF444 | HoxH | 0 | <0.5 | <0.5 | 5 |
| HF424(pGE371) | HoxFU | 0 | <0.5 | ND | 56 |
| HF424(pGE370) | HoxF | 0 | <0.5 | ND | 6 |
a
Cells were grown on fructose-glycerol medium. Activities are given in percentages; values of strain HF424(pGE15) are taken as 100%. Maximal H2-dependent NAD reduction (H2-NAD) is 3.8 μmol of H2 · min−1 · mg−1, and maximal BV reduction (H2-BV) is 1.5 μmol of H2 · min−1 · mg of protein−1. The maximal D2-H+ exchange rate is 0.91 μmol of HD · min−1 · mg of protein−1. Maximal NADH-dependent BV reduction (NADH-BV) is 5.5 μmol of NADH · min−1 · mg of protein−1. Values give the average of data from at least two independent experiments. The relative error was in the range of 10 to 20%.