Fig. 2

Effect of buffer (MOPS) concentrations during the cultivation of wild-type C. bescii in closed-serum bottles without pH control. a Growth properties measured by optical density at 680 nm, b acetate production, and c lactate production as a function of increasing MOPS concentration. Black, 0 mM; green, 20 mM; dark red, 40 mM; light red, 80 mM; blue, 120 mM; purple, 160 mM, gray, 200 mM. d Final pH of media (blue bars) and hydrogen production (red bars) after 36 h cultivation