The family Comamonadaceae

Abstract

The family Comamonadaceae is a large and diverse bacterial family belonging to the order Burkholderiales. It is regularly enlarged with new genera and species and currently comprises over 100 species in the following 29 genera: Acidovorax, Albidiferax, Alicycliphilus, Brachymonas, Caenimonas, Comamonas, Curvibacter, Delftia, Diaphorobacter, Extensimonas, Giesbergeria, Hydrogenophaga, Hylemonella, Lampropedia, Limnohabitans, Macromonas, Malikia, Ottowia, Polaromonas, Pseudacidovorax, Pseudorhodoferax, Ramlibacter, Rhodoferax, Simplicispira, Tepidicella, Variovorax, Verminephrobacter, Xenophilus, and Xylophilus. These genera form a phylogenetic cluster with a relative level of 16S rRNA gene sequence similarity of 93-97 %, yet harbor a remarkable phenotypic diversity that includes aerobic organotrophs, anaerobic denitrifiers and Fe3+-reducing bacteria, hydrogen oxidizers, photoautotrophic and photoheterotrophic bacteria, and fermentative bacteria. Most are environmental bacteria from water and soil habitats; however, some Comamonadaceae are also pathogens, and others have been described from earthworms, rumen fluid, and human clinical samples. Most are mesophiles, although a few have been found in Antarctic habitats and some in hot springs.