Table 2. The most probable number of IRB and MRB, respectively, and the δ34S ratio for sulphate in the three FCCs supplemented with 2.2 mℳ O2 plus 7.9 mℳ N2 (O2:N2), 11 mℳ methane (CH4), and 10 mℳ H2 plus 11 mℳ methane (H2:CH4).
| Sampling day |
IRB (cells ml–1) (95% confidence limits cells ml–1) |
MRB (cells ml–1) (95% confidence limits cells ml–1) |
34SV-CDT(‰) ±s.d., n=3 |
||||||
|---|---|---|---|---|---|---|---|---|---|
| O2:N2 | CH4 | H2:CH4 | O2:N2 | CH4 | H2:CH4 | O2:N2 | CH4 | H2:CH4 | |
| 0 | 140 (60–360) | 140 (60–360) | 80 (36–250) | 500 (200–2000) | 300 (100–1300) | 900 (300–2900) | 29.57 (±0.22) | 29.92 (±0.14) | 30.58 (±0.13) |
| 3 | NA | — | — | — | — | — | 30.27(±0.19) | 30.04 (±0.21) | 29.85 (±0.20) |
| 105 | 2.3 (0.9–8.6) | >1600 (–) | 13 (5–39) | 1.1 (0.4.2.9) | 500 (200–2000) | 1.7 (0.7–4.6) | 29.14 (±0.24) | 31.69 (±0.21) | 32.64 (±0.19) |
Abbreviations: FCC, flow cell cabinet; IRB, iron-reducing bacteria; MRB, manganese-reducing bacteria; NA, not analysed; V-CDT, Vienna Cañon Diablo Meteorite Standard.
s.d., standard deviation.
All isotope ratios are reported in δ34S notation (per mil, ‰) relative to the V-CDT.