Photoreduction of ferredoxin and its use in carbon dioxide fixation by a subcellular system from a photosynthetic bacterium.

Abstract

The synthesis of pyruvate from acetyl coenzyme-A, CO2 and reduced ferredoxin was studied in a subcellular system derived entirely from the photosynthetic bacterium, Chlorobium thiosulfatophilum. The system consisted of chlorophyll-containing particles, catalyzing a light-dependent reduction of ferredoxin with one of several electron donors, and a soluble partly purified enzyme, catalyzing the synthesis of pyruvate from acetyl coenzyme-A, CO2 and reduced ferredoxin. Since none of the electron donors used was able to reduce ferredoxin in the dark, CO2 fixation in this system was strictly light-dependent.