Demonstration of two 3,3'-diaminobenzidine oxidation reactions associated with photosynthetic membranes in anaerobic light-grown Rhodospirillum rubrum.

Photosynthetic membranes of anaerobic light-grown Rhodospirillum rubrum oxidized 3,3'-diaminobenzidine. When glutaraldehyde-treated cells were exposed to 3,3'-diaminobenzidine in the light aerobically, the oxidation appeared to occur by two systems. One reaction was stimulated by white light and the second required molecular oxygen. The O2-dependent activity was inhibited by KCN.