TABLE 3.
Relative free-living and symbiotic hydrogenase activities associated with pALPF1 derivative plasmids containing deletions in hup genes
| Plasmid | Hydrogenase activitya
|
|
|---|---|---|
| Free-living microaerobic cells | Pea bacteroids | |
| pALPF15 (ΔhupS) | <1 | <1 |
| pALPF2 (ΔhupL) | <1 | <1 |
| pALPF4 (ΔhupD) | <1 | <1 |
| pALPF6 (ΔhupG) | 45 | 100 |
| pALPF7 (ΔhupH) | <1 | 50 |
| pALPF8 (ΔhupI) | 10 | 30 |
| pALPF9 (ΔhupJ) | 5 | 40 |
a
Hydrogenase activities associated with pALPF1 derivative plasmids were measured in UPM1155 transconjugant strains and expressed as percentages of hydrogenase activity associated with the wild-type pALPF1 plasmid. The absolute values (100%) of hydrogenase activity for the UPM1155 (pALPF1) strain were (nmol of H2 · h−1 · mg protein−1) 6,520 ± 730 in microaerobic cultures and 4,490 ± 100 in pea bacteroids. Free-living cultures were bubbled with 0.8% O2. Values are averages of three replicates.