Fig 4.
Growth on formate (10 mM) or H2 (138 KPa) in the presence of 1 mM acetate for wild-type G. sulfurreducens (a), a strain deficient in a formate dehydrogenase subunit (b), or a strain deficient in both a formate dehydrogenase subunit and an uptake hydrogenase subunit (c). In controls without added hydrogen or formate, the acetate added as a carbon source could also serve as an electron donor to support growth. Growth of the double mutant growth on 15 mM acetate is also shown (c) to demonstrate that cells were viable yet unable to grow on formate or H2. The results are the means and standard deviations for triplicate cultures.