Chromatiaceae

Chromatiaceae
Microscopic image (600x magnification) of the species Chromatium okenii, belonging to the family Chromatiaceae
Scientific classification
Domain:	Bacteria
Phylum:	Pseudomonadota
Class:	Gammaproteobacteria
Order:	Chromatiales
Family:	Chromatiaceae Bavendamm 1924 (Approved Lists 1980)[1]
Genera[1]
"Ca. Nitrosoglobus" Hayatsu et al. 2017 "Ca. Tenderia" Eddie et al. 2017 "Pararheinheimera" Sisinthy et al. 2017 "Rhodothece" Molisch 1906 "Thioflavicoccus" Imhoff and Pfennig 2001 "Thiothece" Winogradsky 1888 "Vampirococcus" Guerrero et al. 1986 Alishewanella Fonnesbech Vogel et al. 2000 Allochromatium Imhoff et al. 1998 Amoebobacter Winogradsky 1888 (Approved Lists 1980) Caldichromatium Saini et al. 2020 Chromatium Perty 1852 (Approved Lists 1980) Halochromatium Imhoff et al. 1998 Imhoffiella Nupur et al. 2017 Isochromatium Imhoff et al. 1998 Lamprobacter Gorlenko et al. 1988 Lamprocystis Schroeter 1886 (Approved Lists 1980) Marichromatium Imhoff et al. 1998 Monas Nitrosococcus Winogradsky 1892 (Approved Lists 1980) Ophidomonas Pfennigia Tindall 1999 Phaeobacterium Nupur et al. 2015 Phaeochromatium Shivalia et al. 2012 Rhabdochromatium (ex Winogradsky 1888) Dilling et al. 1996 Rheinheimera Brettar et al. 2002 Thermochromatium Imhoff et al. 1998 Thialkalicoccus Bryantseva et al. 2000 Thiobaca Rees et al. 2002 Thiocapsa Winogradsky 1888 (Approved Lists 1980) Thiococcus (ex Eimhjellen et al. 1967) Imhoff et al. 1998 Thiocystis Winogradsky 1888 (Approved Lists 1980) Thiodictyon Winogradsky 1888 (Approved Lists 1980) Thiohalocapsa Imhoff et al. 1998 Thiolamprovum Guyoneaud et al. 1998 Thiopedia Winogradsky 1888 (Approved Lists 1980) Thiophaeococcus Anil Kumar et al. 2008 Thiorhodococcus Guyoneaud et al. 1998 Thiorhodovibrio Overmann et al. 1993 Thiospirillum Winogradsky 1888 (Approved Lists 1980)

The Chromatiaceae are one of the two families of purple sulfur bacteria, together with the Ectothiorhodospiraceae. They belong to the order Chromatiales of the class Gammaproteobacteria, which is composed by unicellular Gram-negative organisms.^[2][3] Most of the species are photolithoautotrophs and conduct an anoxygenic photosynthesis, but there are also representatives capable of growing under dark and/or microaerobic conditions as either chemolithoautotrophs or chemoorganoheterotrophs.^[3][4]

Both Ectothiorhodospiraceae and Chromatiaceae bacteria produce elemental sulfur globules, the difference is that in the second case they are stored inside the cells rather than outside. Sulfur is an intermediate in the oxidization of sulfide, which is ultimately converted into sulfate, and may serve as a reserve.^[2]