Fig. 2.

Cell growth and acetic acid production using either CO or H₂ as a reducing gas at a composition of 7/3 CO/CO₂ or 7/3 H₂/CO₂ and a flow rate of 1,000 sccm. The maximum cell density under H₂ (max OD of ∼2.5) is less than one-quarter of that achieved with CO (max OD of ∼11) as electron donor. Substantial amounts of acetic acid (∼30 g/L) are produced under both conditions. SDs from triplicate runs are presented.