Table 2 Initial stable hydrogen isotopic conditions for the hydrogenotrophic methanogenesis experiments
Batches | Isotope labeling | Initial value | \( {\updelta}^{\mathrm{eq}}{\mathrm{D}}_{{\mathrm{H}}_2\hbox{--} {\mathrm{H}}_2\mathrm{O}} \) | ||
|---|---|---|---|---|---|
D2O | DH | \( {\updelta \mathrm{D}}_{{\mathrm{H}}_2\mathrm{O}} \) | \( {\updelta \mathrm{D}}_{{\mathrm{H}}_2} \) | ||
Thermophilic coculture experimental set (TC, at 55 °C) | |||||
A1 | − | − | −58 | − | − |
A2 | − | − | −62 | − | − |
A3 | + | − | +1624 | − | − |
A4 | + | − | +1639 | − | − |
A5 | ++ | − | +3771 | − | − |
A6 | ++ | − | +3787 | − | − |
Mesophilic coculture experimental set (MC, at 25 °C) | |||||
B1 | − | − | −62 | − | − |
B2 | − | − | −58 | − | − |
B3 | + | − | +1406 | − | − |
B4 | + | − | +1413 | − | − |
B5 | ++ | − | +3662 | − | − |
B6 | ++ | − | +3286 | − | − |
Thermophilic pure culture experimental set (TP, at 60 °C) | |||||
C1 | − | − | −59 | −358 | DH-rich |
C2 | − | + | −53 | +330 | DH-rich |
C3 | + | − | +1097 | −287 | Equilibrated |
C4 | + | ++ | +1210 | +1886 | DH-rich |
C5 | ++ | − | +2574 | −350 | D2O-rich |
C6 | ++ | + | +2317 | +70 | Equilibrated |
Mesophilic pure culture experimental set (MP, at 30 °C) | |||||
D1 | − | − | −54 | −344 | DH-rich |
D2 | + | + | +1427 | +145 | DH-rich |
D3 | + | + | +1424 | +22 | DH-rich |
D4 | + | − | +1369 | −350 | Equilibrated |
D5 | + | − | +1382 | −349 | Equilibrated |
D6 | ++ | − | +3096 | −351 | D2O-rich |
D7 | ++ | + | +3142 | +85 | Equilibrated |