Fig. 4

Effect of bicarbonate on the ATP content of resting cells and ATP hydrolysis catalyzed by membranes of T. kivui. 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) in the absence or presence of KHCO₃ and the ATP content of cells were determined. Squares, without bicarbonate; triangles, 50 mM KHCO₃; diamonds, 300 mM KHCO₃. b Membranes from T. kivui were incubated for 3 min in the presence (300 mM KHCO₃ or 300 mM NaHCO₃) or absence of bicarbonate in buffer (100 mM Tris/HCl, 20 mM MgSO₄, 20 mM KCl, pH 7.0) and the ATP hydrolysis of membranes was determined