TABLE 1

Carbon isotopic composition of CO2 and CH4 of culture and coculture experiments

Growth conditionInitial H2 (aqc) (μM)δ13C value (‰)εCO2-CH4 (‰)
CO2 (aq)CH4, Tf
ToTf
M. jannaschii only
    Chemostat R183−35.1−29.0−55.928.5
    Chemostat R280−34.6−28.2−55.929.3
    Chemostat R380−35.2−28.4−55.829.0
    Chemostat R418−35.9−33.3−75.745.9
    Chemostat R515−35.7−31.8−74.245.8
    Chemostat R627−35.8−32.0−72.543.7
    Bottle B11,200a−26.1+22.6−32.922.1b
    Bottle B21,200a−26.1+19.2−34.223.0b
M. jannaschii-T. paralvinellae coculture
    Bottle B3 (formate)0−26.7−22.8−99.485.1
    Bottle B4 (formate)0−26.7−23.0−99.484.8
    Bottle B5 (maltose)0−25.5−24.4−91.273.5
    Bottle B6 (maltose)0−25.5−21.6−89.073.9
  • a Estimated at 82°C using the Geochemist’s Workbench Standard 10.0 (Aqueous Solutions, LLC, Champaign, Illinois, USA).

  • b Calculated based on the isotopic compositions of the starting CO2, final CO2, and accumulated methane.

  • c aq, aqueous concentration.