Fig. 3

Effect of bicarbonate on product formation from H₂ + CO₂. a Resting cells of T. kivui (1 mg/mL) were incubated in anoxic buffer (50 mM Imidazole, 20 mM KCl, 20 mM MgSO₄, 2 mM DTE, 4 µM resazurin, pH 7.0) with H₂ + CO₂ (80:20%, 2 × 10⁵ Pa). b 50 mM or c 300 mM KHCO₃ were added to the cell suspensions before the experiment was started by replacing the gas phase. Squares, acetic acid; triangles, formic acid