FIG 4.
Gas concentrations over time in mono- and cocultures of C. minuta, B. thetaiotaomicron, and M. smithii grown under different conditions. (a to e) H2 (orange) and CH4 (blue) concentrations in the headspace over time in cultures from batches 1 to 3 (Table S1). Points represent the averages of results from 3 biological replicates for each condition, and red bars join the minimal and maximal values. In conditions where H2 was provided in excess (H2, 2 × 105 Pa, and atmospheric (atm) H2, with the headspace initially composed of 80:20, vol/vol, H2-CO2), its concentrations are not shown for scale reasons. Initial concentrations of H2 under conditions where it was not provided in the headspace were undetectable (N2, 2 × 105 Pa, and atmospheric N2, with the headspace initially composed of 80:20, vol/vol, N2-CO2) and stayed null in the monocultures of M. smithii (not shown). CH4 concentrations in the bacterial monocultures were undetectable and are not shown as well. (a to c) Same y scale as in panels d and e.