''Chromatium okenii'' is a

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

found in

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

. It belongs to the

Purple sulfur bacteria The purple sulfur bacteria (PSB) are part of a group of Pseudomonadota capable of photosynthesis, collectively referred to as purple bacteria. They are anaerobic or microaerophilic, and are often found in stratified water environments including ...

.George M. Garrity: ''

Bergey's Manual of Systematic Bacteriology ''Bergey's Manual of Systematic Bacteriology'' is the main resource for determining the identity of prokaryotic organisms, emphasizing bacterial species, using every characterizing aspect. The manual was published subsequent to the ''Bergey's Manu ...

''. 2. Auflage. Springer, New York, 2005, Volume 2: ''The Proteobacteria, Part B: The Gammaproteobacteria'' These bacteria are capable of

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

and use

Hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The unde ...

(H₂S) as an

electron donor In chemistry, an electron donor is a chemical entity that donates electrons to another compound. It is a reducing agent that, by virtue of its donating electrons, is itself oxidized in the process. Typical reducing agents undergo permanent chem ...

for CO₂ reduction and so do not produce oxygen. This type of photosynthesis is called

anoxygenic photosynthesis Bacterial anoxygenic photosynthesis differs from the better known oxygenic photosynthesis in plants by the reductant used (e.g. hydrogen sulfide instead of water) and the byproduct generated (e.g. elemental sulfur instead of molecular oxygen). Ba ...

. ''Chromatium okenii'' is

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: * Anaerobic adhesive, a bonding a ...

and the cells are slightly curved or straight rods.

References

External links

''Chromatium''
J.P. Euzéby: List of Prokaryotic names with Standing in Nomenclature Chromatiales Bacteria described in 1838 {{Chromatiales-stub