Fig. 2.

Growth experiments with strains of O. carboxidovorans in which the genes coxE (E::km) (a), coxF (F::km) (b) or coxG (G::km) (c) were inactivated by insertional mutagenesis. Bacteria were cultivated under chemolithoautotrophic conditions employing the following gas mixtures (v/v): 45 % CO, 5 % CO₂, and 50 % air (filled circle); 40 % H₂, 10 % CO₂, and 50 % air (open circle); and 30 % H₂, 5 % CO₂, 30 % CO, and 35 % air (filled square). Each data point represents the average of three optical density measurements on separate samples of the same culture. The standard deviation of such measurements was below 2.8 %. For further details see the “Materials and methods” section