FIG 3.

CO consumption, acetate production, and H₂ formation in cells growing on increasing concentrations of CO. The gas phase consisted of 30% CO (A), 50% CO (B), or 70% CO (C). N₂ plus CO₂ (80:20 [vol/vol]) was used as the makeup gas at a final pressure of 2 × 10⁵ Pa. All cultures were grown in complex medium, and growth was measured by monitoring the optical density (●) at 600 nm. The concentrations of CO (▼) and H₂ (◆) in the gas phase and of acetate in the liquid phase (○) were determined by gas chromatography. Shown are data from one representative experiment out of three independent replicates.