Table 3. [13C]methane and carbon dioxide production by M. barkeri strains.
| Substrate | CH4 produced, μmol | % 13CH4 | CO2 produced, μmol | % 13CO2 | CH4:CO2 |
|---|---|---|---|---|---|
| M. barkeri Δmtr | |||||
| 13CH3OH | 72 ± 6 | 99 | 22 ± 2 | 95 | 3.2:1 |
| 13CH3OH + CH3COO− | 440 ± 6 | 98 | 130 ± 2 | 4 | 3.4:1 |
| CH3OH + 13CH3COO− | 396 ± 27 | <1 | 125 ± 6 | 36 | 3.2:1 |
| CH3OH + CH313COO− | 364 ± 11 | <1 | 124 ± 3 | 62 | 2.9:1 |
| M. barkeri | |||||
| 13CH3OH | 345 ± 17 | 99 | 116 ± 6 | 97 | 3:1 |
| 13CH3OH + CH3COO− | 378 ± 6 | 98 | 133 ± 3 | 92 | 2.8:1 |
| CH3OH + 13CH3COO− | 312 ± 11 | <1 | 126 ± 5 | 2 | 2.5:1 |
| CH3OH + CH313COO− | 322 ± 6 | <1 | 126 ± 1 | 5 | 2.6:1 |
Assays contained 500 μmol methanol and/or 500 μmol acetate and were conducted as described in Materials and Methods; gas phase was either N2/CO2 (80%/20%) or H2/CO2 (80%/20%) at 250 kPa.