Photosynthesis Without the Organisms: The Bacterial Chromatophores

Anoxygenic photosynthetic bacteria are an extremely old form of life that inhabits planet Earth since approximately 3 Gya. They represent the model system for the far more complex photosynthetic organisms appeared later in time, i.e. cyanobacteria, algae and plants, and capable of performing the oxygenic photosynthesis. In this chapter we wish to present a short review of the cell architecture of one specific phototrophic bacterium, namely Rhodobacter sphaeroides, devoting particular attention to cytoplasmic membrane and its invagination originating under anoxygenic conditions and exposure to light. The structure and enzyme organization of the so-called chromatophores of two strains of Rhodobacter sphaeroides are presented, along with the isolation and purification procedures.