Fig. 3.

Photoheterotrophic growth of the R. rubrum wild type (UR2), the cbbM mutant (UR5251), and other cbb mutants. A culture grown in SMN medium (0.4 ml) was used to inoculate 25 ml of MG medium and then grown under phototrophic and anaerobic conditions. This fairly heavy inoculum of the culture grown in SMN medium allows growth in MG medium to an OD₆₀₀ of approximately 0.2 to 0.3 (after 1 day) before growth defects of cbbM mutants are apparent. All single mutants are listed in A, and all double mutants are shown in B, while the wild type (UR2) and the cbbM mutant (UR5251) are shown in both panels for comparison.