ABSTRACT
The phototrophic bacteria are a physiological group of different kinds of Gram-negative aquatic bacteria. They are considered to be evolutionary rather old, representing the first phototrophic organisms on our planet.1 The common characteristic of the Rhodospirillales is their ability to perform an anaerobic type of photosynthesis, which — unlike the photosynthesis of Cyanophyceae and green plants — proceeds without the production of oxygen. All Rhodospirillales contain photosynthetic pigments of the bacteriochlorophyll type (see Table 1), different from plant chlorophylls, and typical carotenoid pigments (see Table 2).
