TABLE 2.
Induction of BMO activity in wild-type “P. butanovora” and β-galactosidase activity in the lacZ-BMO fusion in response to various substrates and products of BMO
| Compound | Concn (μM) | BMO activity in wild type (% of butane control) | LacZ activity in reporter strain (Miller units)e |
|---|---|---|---|
| Butane | 50 | 100 | 0 |
| 1-Butanol | 50 | >10b | 263 ± 68 |
| Butyrate | 50 | 0 | 0 |
| Ethylene | 517a | 24c | 0 |
| Ethylene oxide | 8,000a | NDd | 89 ± 13 |
| PCE | 50 | 0 | 0 |
| TCE | 50 | 0 | 0 |
| 1,2-trans DCE | 50 | 47 | 84 ± 36 |
| 1,2-cis DCE | 50 | 25 | 0 |
| 1,1-DCE | 50 | 0 | 0 |
Gas added as 10% headspace.
1-Butanol is consumed during the 4-h incubation, and the extent of induction of BMO relative to butane could not be accurately determined in wild-type cells.
Ethene oxide accumulation was measured during a 4-h incubation of lactate-grown cells in the presence of ethene.
ND, not determined. Ethene oxide, in the absence of ethene, inhibits BMO activity in wild-type cells, and induction of BMO could not be accurately quantified in wild-type cells.
Results indicate the increase in β-galactosidase above the level of the buffer control. Background levels of β-galactosidase were typically about 50 Miller units.