The family Erythrobacteraceae

Abstract

Erythrobacteraceae is one of the two families that belong to the order Sphingomonadales, and it is affiliated with the class Alphaproteobacteria. The family Erythrobacteraceae includes five genera - Altererythrobacter, Croceicoccus, Erythrobacter, Erythromicrobium and Porphyrobacter - for a total of 33 species, including 29 with validly published names and 4 new species. Members of the family are Gram-negative, aerobic, rod-shaped or pleomorphic coccoid bacteria; they are motile or nonmotile, chemo-organotrophic, produce pigments (yellow, orange, red or pink), and do not form spores. Some species require biotin. Most members contain bacteriochlorophyll a (BChl a), several types of carotenoids, and monosaccharide-type glycosphingolipid. Representatives of the clade have been isolated from diverse environments: wild rice, cold-seep sediment, desert sand, tepid water, seawater, tidal flats, marine sediment, and marine invertebrates. Whole-genome sequencing has been reported in only two genera of the Erythrobacteraceae family, including Erythrobacter (three strains) and Porphyrobacter (one strain). Family members offer a valuable source of information for further studies focused on aerobic anoxygenic phototrophic (AAP) metabolism, physiological nature, and high potential for biotechnological purposes by the presence of important hydrolases.