Alphaproteobacteria

Alphaproteobacteria
Transmission electron micrograph of Wolbachia within an insect cell. Credit:Public Library of Science / Scott O'Neill
Scientific classification
Domain:	Bacteria
Phylum:	Proteobacteria
Class:	Alphaproteobacteria
Orders
'Candidatus Alysiosphaera europeae' 'Candidatus Catenimonas italica' 'Candidatus Monilibacter batavus' 'Candidatus Pelagibacter ubique' Rappe et al. 2002 'Candidatus Puniceispirillum marinum' Oh et al. 2010 Caulobacterales Caulobacteraceae Kiloniellales Kiloniellaceae Kopriimonadales ♠ Kopriimonadaceae ♠ Kordiimonadales "Kordiimonadaceae" "Parvularculales" "Parvularculaceae" Rhizobiales "Aurantimonadaceae" Bartonellaceae Beijerinckiaceae Bradyrhizobiaceae Brucellaceae Cohaesibacteraceae Hyphomicrobiaceae Methylobacteriaceae Methylocystaceae Phyllobacteriaceae Rhizobiaceae Rhodobiaceae Xanthobacteraceae Rhodobacterales Rhodobacteraceae Rhodospirillales Acetobacteraceae Rhodospirillaceae Rickettsiales Anaplasmataceae Holosporaceae Rickettsiaceae Sneathiellales Sneathiellaceae Sphingomonadales Erythrobacteraceae Sphingomonadaceae

Alphaproteobacteria is a class of Proteobacteria. Like all Proteobacteria, they are Gram-negative.

Characteristics

The Alphaproteobacteria comprise most phototrophic genera, but also several genera metabolising C1-compounds (e.g., Methylobacterium spp.), symbionts of plants (e.g., Rhizobium spp.) and animals, and a group of pathogens, the Rickettsiaceae. Moreover the precursors of the mitochondria of eukaryotic cells are thought to have originated from Rickettsia spp. in this class (See endosymbiotic theory.). Because of their symbiotic properties, scientists often use Alphaproteobacteria of the genus Agrobacterium to transfer foreign DNA into plant genomes, and they also have many other biotechnological properties. Aerobic anoxygenic phototrophic bacteria are alphaproteobacteria that are a widely distributed marine plankton that may constitute over 10% of the open ocean microbial community.

There have been seven orders described.

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) and the phylogeny is based on 16S rRNA-based LTP release 106 by 'The All-Species Living Tree' Project

?Aquaspirillum polymorphum ♠ (Williams and Rittenberg 1957) Hylemon et al. 1973 ?Furvibacter ♠ ?Kopriimonas byunsanensis ♠ Kwon et al. 2005 ?Micavibrio aeruginosavorus ♠ Lambina et al. 1983 ?Polymorphum gilvum ♠ Cai 2010 ?Reyranella massiliensis Pagnier et al. 2011 ?Ronia tepidophila ♠ ?Subaequorebacter tamlense ♠ Lee 2006 ?Tuberoidobacter mutans ♠ ?Vibrio adaptatus Muir et al. 1990 ?Vibrio cyclosites Muir et al. 1990 Rhodovibrio Rhodospirillaceae 2 Tistrella Rhodospirillaceae 3 Rhodospirillaceae 4 Defluviicoccus vanus Maszenan et al. 2005 Elioraea tepidiphila Albuquerque et al. 2008 Acetobacteraceae Rickettsiales [incl. Mitochondrion] Sneathiella Sphingomonadaceae [incl. Erythrobacteraceae, Caulobacter leidyi, Asticcacaulis] Rhodothalassium salexigens (Drews 1982) Imhoff et al. 1998 Kordiimonas Rhodospirillaceae 1 [incl. Roseospirillum parvum, Kiloniella laminariae, Terasakiella pusilla] Rhizobiales [incl. Caulobacteraceae, Rhodobacteraceae, Parvularcula & Streptomyces longisporoflavus]

Notes:
♠ Strains found at the National Center for Biotechnology Information (NCBI) but not listed in the List of Prokaryotic names with Standing in Nomenclature (LSPN)

External links

• MeSH Alphaproteobacteria
• Bacterial (Prokaryotic) Phylogeny Webpage: Alpha Proteobacteria.