Table 1: Observed partial pressures and the calculated Gibbs free energy change of CO conversion by C. hydrogenoformans in batch culture.

Culture 𝑡 (h)H2 (Pa)CO (Pa)CO2 (Pa)Acetate (mM) Δ 𝐺 R 1 (a) Δ 𝐺 R 2 (a)

−CO2 trap0.5 6 . 0 1 0 2 2 . 4 1 0 5 1 . 1 1 0 3 0.2 (b)−53−52
9.5 2 . 0 1 0 5 1 . 8 1 0 4 1 . 3 1 0 5 −16
55 2 . 0 1 0 5 3 . 9 1 0 1 1 . 3 1 0 5 3.8+1−18

+CO2 trap0.5 2 . 2 1 0 2 2 . 6 1 0 5 8 . 4 1 0 2 0.2−57−52
12.5 2 . 0 1 0 5 1 . 4 1 0 4 1 . 2 1 0 4 −22
55 2 . 1 1 0 5 0 . 4 1 0 0 3 . 5 1 0 2 0.2−3−16

(a) Δ 𝐺 R 1 and Δ 𝐺 R 2 : Gibbs free energy change (kJ/mol CO) for reaction (1) and reaction (2), respectively, at 70°C [10].
(b)Underlined: detection limits that were used in calculation of free energy.