Kinetic studies on formation of cytochrome oxidase of Rhodopseudomonas capsulata after a shift from phototrophic to chemotrophic growth.

Rhodopseudomonas capsulata cells were shifted from phototrophic (anaerobic, light) to chemotrophic (semiaerobic, dark, 10% air saturation) growth conditions. During the adaptation period of 4 h, the bacteriochlorophyll content of cells and membranes decreased, and a newly synthesized 65-kilodalton polypeptide of the cytochrome oxidase was incorporated into the membrane fraction. The enzymatic activity of the cytochrome oxidase increased strongly after a lag time of 2 h. The amount of cytochrome oxidase protein does not follow the same kinetics. The relative amount of a membrane-bound cytochrome c of low molecular weight, which has been proposed to be a donor for the cytochrome oxidase, increased during adaptation.