The membrane-bound purple bacterial photosystem
Purple bacterial photosynthetic membrane vesicles
The purple non-sulphur bacteria are not just purple. The picture shows how different strains and growth conditions can affect color (pigmentation) of the purple non-sulphur bacterium Rhodobacter capsulatus. Also included is the bacterium Rhodopseudomonas palustris. Cultures were grown in test tubes, and placed in a plastic rack for photography. From left to right: R. capsulatus strains SB1003 (aerobic), SB1003 (anaerobic), DE442 (aerobic), SB1003-Ph6 (anaerobic, unknown mutation), SB1003-Ph4 (aerobic, unknown mutation) and R. palustris strain CGA001 (anaerobic).