The purple sulfur bacteria are a group of Proteobacteria capable of photosynthesis, collectively referred to as purple bacteria. They are anaerobic or microaerophilic, and are often found in sulfur springs or stagnant water. Unlike plants and algae, they do not use water as their reducing agent, and so do not produce oxygen. Instead they use hydrogen sulfide, which is oxidized to produce granules of elemental sulfur. This in turn may be oxidized to form sulfuric acid.
The purple sulfur bacteria are divided into two families, the Chromatiaceae and Ectothiorhodospiraceae, which respectively produce internal and external sulfur granules, and show differences in the structure of their internal membranes. They make up the order Chromatiales, included in the gamma subdivision of the Proteobacteria. The genus Halothiobacillus is also included in the Chromatiales, in its own family, but it is not photosynthetic.
The purplesulfurbacteria are a group of Proteobacteria capable of photosynthesis, collectively referred to as purplebacteria.
The purplesulfurbacteria are divided into two families, the Chromatiaceae and Ectothiorhodospiraceae, which respectively produce internal and external sulfur granules, and show differences in the structure of their internal membranes.
Purplesulfurbacteria are generally found in illuminated anoxic zones of lakes and other aquatic habitats where hydrogen sulfide accumulates and also in "sulfur springs" where geochemically or biologically produced hydrogen sulfide can trigger the formation of blooms of purplesulfurbacteria.
Diffusion of hydrogen sulfide produced by the anaerobic bacteria, from the sediment into the water column above supports the growth of anaerobic photosynthetic bacteria such as green sulfurbacteria and purplesulfurbacteria.
These bacteria are able to utilize sunlight to generate energy and can use carbon dioxide in a oxygen-free reaction to produce compounds needed for growth.
Winogradsky was born in Kiev, in what was then the Russian Empire, and attended the University of Saint Petersburg in 1881, studying natural sciences and receiving a degree of master of science in botany in 1884.
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