A genus of gram-negative, ovoid to rod-shaped bacteria that is phototrophic. All species use ammonia as a nitrogen source. Some strains are found only in sulfide-containing freshwater habitats exposed to light while others may occur in marine, estuarine, and freshwater environments.

Organelles of phototrophic bacteria which contain photosynthetic pigments and which are formed from an invagination of the cytoplasmic membrane.

A family of phototrophic purple sulfur bacteria that deposit globules of elemental sulfur inside their cells. They are found in diverse aquatic environments.

Inorganic salts of thiosulfuric acid possessing the general formula R2S2O3.

Pyrrole containing pigments found in photosynthetic bacteria.

A genus of gram-negative, spiral bacteria that possesses internal photosynthetic membranes. Its organisms divide by binary fission, are motile by means of polar flagella, and are found in aquatic environments.

An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.

A subtype of thioredoxins found primarily in CHLOROPLASTS.

Iron-containing proteins that transfer electrons, usually at a low potential, to flavoproteins; the iron is not present as in heme. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)