Fig. 5
From: Efficient whole cell biocatalyst for formate-based hydrogen production
H2 production in closed batch fermentation by fructose-grown cells. A. woodii was grown in 50 mL carbonate-free growth medium with 20 mM fructose at 30 °C in a shaking water bath. At the point indicated, production phase was initiated by addition of sodium formate, ETH2120, or ethanol (solvent of ETH2120 as negative control). At this time point, the optical density of all cultures was between 0.35 and 0.45. H2 was measured in the gas phase and is plotted as mmol H2 per liter of growth medium (a). Substrate and product balance during the production phase (b) is shown as difference between t = 1 h (addition of formate and ionophore) and t = 24 h (end of fermentation). Squares, 300 mM sodium formate, 30 µM ETH2120; triangles up, 300 mM sodium formate, 20.5 mM ethanol; diamonds, 20.5 mM ethanol; triangles down, 30 µM ETH2120