Etymology:Gr. neut. n.alpha, name of the first letter of Greek alphabet (indeclinable); Gr. masc. n.Prôteus, Greek god of the sea, capable of assuming many different shapes; N.L. neut. pl. n.bacteria, plural of bacterium; N.L. neut. pl. n.Alphaproteobacteria, a class of bacteria included in the phylum Proteobacteria and having 16S rRNA gene sequences related to those of the members of the order Caulobacterales (not formed from a genus name)
Effective publication:
Garrity GM, Bell JA, Lilburn T. Class I. Alphaproteobacteria class. nov. In: Brenner DJ, Krieg NR, Staley JT, Garrity GM (eds), Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 2 (The Proteobacteria), part C (The Alpha-, Beta-, Delta-, and Epsilonproteobacteria), Springer, New York, 2005, p. 1.
IJSEM list:
Euzeby JP. Validation list no. 107. List of new names and new combinations previously effectively, but not validly, published. Int J Syst Evol Microbiol 2006; 56:1-6.
Nomenclatural status:
validly published under the ICNP
heterotypic synonym, validly published under the ICNP, rejected name
Notes:
🥇 Nomenclatural type of the phylum "Alphaproteobacteraeota" Oren et al. 2015.Publication:
Oren A, da Costa MS, Garrity GM, Rainey FA, Rossello-Mora R, Schink B, Sutcliffe I, Trujillo ME, Whitman WB. Proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2015; 65:4284-4287.
🥇 Nomenclatural type of the phylum "Alphaproteobacteriota" Whitman et al. 2018.Publication:
Whitman WB, Oren A, Chuvochina M, da Costa MS, Garrity GM, Rainey FA, Rossello-Mora R, Schink B, Sutcliffe I, Trujillo ME, et al. Proposal of the suffix -ota to denote phyla. Addendum to 'Proposal to include the rank of phylum in the International Code of Nomenclature of Prokaryotes'. Int J Syst Evol Microbiol 2018; 68:967-969.
🧕 Brenner et al. (2005) assigned this class to the phylum "Proteobacteria" Gray and Herwig 1996.Publication:
Garrity GM, Bell JA, Lilburn T. Class III. Gammaproteobacteria class. nov. In: Brenner DJ, Krieg NR, Staley JT, Garrity GM (eds), Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 2 (The Proteobacteria), part B (The Gammaproteobacteria), Springer, New York, 2005, p. 1.
🧒 Brenner et al. (2005) assigned the order Rhizobiales Kuykendall 2006 to this class.Publication:
Garrity GM, Bell JA, Lilburn T. Class I. Alphaproteobacteria class. nov. In: Brenner DJ, Krieg NR, Staley JT, Garrity GM (eds), Bergey's Manual of Systematic Bacteriology, 2nd edn, vol. 2 (The Proteobacteria), part C (The Alpha-, Beta-, Delta-, and Epsilonproteobacteria), Springer, New York, 2005, p. 1.
🧒 Chen et al. (2017) assigned the genus Enterovirga Chen et al. 2017 to this class.Publication:
Chen X, Li QY, Li GD, Lei H, Jiang Y, Han L, Huang XS, Jiang CL. Enterovirga rhinocerotis gen. nov., sp. nov., isolated from Rhinoceros unicornis faeces. Antonie Van Leeuwenhoek 2017; 110:553-562.
🧒 Eschbach et al. (2009) assigned the genus "Candidatus Paraholospora" Eschbach et al. 2009 to this class.Publication:
Eschbach E, Pfannkuchen M, Schweikert M, Drutschmann D, Brummer F, Fokin S, Ludwig W, Gortz HD. "Candidatus Paraholospora nucleivisitans", an intracellular bacterium in Paramecium sexaurelia shuttles between the cytoplasm and the nucleus of its host. Syst Appl Microbiol 2009; 32:490-500.
🧒 Ferla et al. (2013) assigned the subclass "Caulobacteridae" Ferla et al. 2013 to this class.Publication:
Ferla MP, Thrash JC, Giovannoni SJ, Patrick WM. New rRNA gene-based phylogenies of the Alphaproteobacteria provide perspective on major groups, mitochondrial ancestry and phylogenetic instability. PLoS One 2013; 8:e83383.
🧒 Ferla et al. (2013) assigned the subclass "Magnetococcidae" Ferla et al. 2013 to this class.Publication:
Ferla MP, Thrash JC, Giovannoni SJ, Patrick WM. New rRNA gene-based phylogenies of the Alphaproteobacteria provide perspective on major groups, mitochondrial ancestry and phylogenetic instability. PLoS One 2013; 8:e83383.
🧒 Ferla et al. (2013) assigned the subclass "Rickettsidae" Ferla et al. 2013 to this class.Publication:
Ferla MP, Thrash JC, Giovannoni SJ, Patrick WM. New rRNA gene-based phylogenies of the Alphaproteobacteria provide perspective on major groups, mitochondrial ancestry and phylogenetic instability. PLoS One 2013; 8:e83383.
🧒 Ferla et al. (2013) assigned the subclass "Rickettsiidae" corrig. Ferla et al. 2013 to this class.Publication:
Ferla MP, Thrash JC, Giovannoni SJ, Patrick WM. New rRNA gene-based phylogenies of the Alphaproteobacteria provide perspective on major groups, mitochondrial ancestry and phylogenetic instability. PLoS One 2013; 8:e83383.
🧒 Kevbrin et al. (2021) assigned the order Maricaulales Kevbrin et al. 2021 to this class.Publication:
Kevbrin V, Boltyanskaya Y, Koziaeva V, Uzun M, Grouzdev D. Alkalicaulis satelles gen. nov., sp. nov., a novel haloalkaliphile isolated from a laboratory culture cyanobacterium Geitlerinema species and proposals of Maricaulaceae fam. nov., Robiginitomaculaceae fam. nov., Maricaulales ord. nov. and Hyphomonadales ord. nov. Int J Syst Evol Microbiol 2021; 71:4614.
🧒 Kragelund et al. (2006) assigned the genus "Candidatus Sphaeronema" Levantesi et al. 2004 to this class.Publication:
Kragelund C, Kong Y, van der Waarde J, Thelen K, Eikelboom D, Tandoi V, Thomsen TR, Nielsen PH. Ecophysiology of different filamentous Alphaproteobacteria in industrial wastewater treatment plants. Microbiology (Reading) 2006; 152:3003-3012.
🧒 Kragelund et al. (2006) assigned the genus "Candidatus Halyseosphaera" corrig. Kragelund et al. 2006 to this class.Publication:
Kragelund C, Kong Y, van der Waarde J, Thelen K, Eikelboom D, Tandoi V, Thomsen TR, Nielsen PH. Ecophysiology of different filamentous Alphaproteobacteria in industrial wastewater treatment plants. Microbiology (Reading) 2006; 152:3003-3012.
🧒 Liang et al. (2021) assigned the family Roseobacteraceae Liang et al. 2021 to this class.Publication:
Liang KYH, Orata FD, Boucher YF, Case RJ. Roseobacters in a Sea of Poly- and Paraphyly: Whole Genome-Based Taxonomy of the Family Rhodobacteraceae and the Proposal for the Split of the "Roseobacter Clade" Into a Novel Family, Roseobacteraceae fam. nov. Front Microbiol 2021; 12:683109.
🧒 Matsuura et al. (2012) assigned the genus "Candidatus Lariskella" Matsuura et al. 2012 to this class.Publication:
Matsuura Y, Kikuchi Y, Meng XY, Koga R, Fukatsu T. Novel clade of alphaproteobacterial endosymbionts associated with stinkbugs and other arthropods. Appl Environ Microbiol 2012; 78:4149-4156.
🧒 Proença et al. (2018) assigned the family Geminicoccaceae Proença et al. 2018 to this class.Publication:
Proenca DN, Whitman WB, Varghese N, Shapiro N, Woyke T, Kyrpides NC, Morais PV. Arboriscoccus pini gen. nov., sp. nov., an endophyte from a pine tree of the class Alphaproteobacteria, emended description of Geminicoccus roseus, and proposal of Geminicoccaceae fam. nov. Syst Appl Microbiol 2018; 41:94-100.
🧒 Ruiz-Perez et al. (2021) assigned the genus "Candidatus Anoxipelagibacter" Ruiz-Perez et al. 2021 to this class.Publication:
Ruiz-Perez CA, Bertagnolli AD, Tsementzi D, Woyke T, Stewart FJ, Konstantinidis KT. Description of Candidatus Mesopelagibacter carboxydoxydans and Candidatus Anoxipelagibacter denitrificans: Nitrate-reducing SAR11 genera that dominate mesopelagic and anoxic marine zones. Syst Appl Microbiol 2021; 44:126185.
🧒 Suarez et al. (2014) assigned the genus Hartmannibacter Suarez et al. 2014 to this class.Publication:
Suarez C, Ratering S, Geissler-Plaum R, Schnell S. Hartmannibacter diazotrophicus gen. nov., sp. nov., a phosphate-solubilizing and nitrogen-fixing alphaproteobacterium isolated from the rhizosphere of a natural salt-meadow plant. Int J Syst Evol Microbiol 2014; 64:3160-3167.
🧒 Szokoli et al. (2016) assigned the family Holosporaceae Görtz and Schmidt 2006 to this class.Publication:
Szokoli F, Castelli M, Sabaneyeva E, Schrallhammer M, Krenek S, Doak TG, Berendonk TU, Petroni G. Disentangling the Taxonomy of Rickettsiales and Description of Two Novel Symbionts ("Candidatus Bealeia paramacronuclearis" and "Candidatus Fokinia cryptica") Sharing the Cytoplasm of the Ciliate Protist Paramecium biaurelia. Appl Environ Microbiol 2016; 82:7236-7247.
🧒 Wiese et al. (2009) assigned the order Kiloniellales Wiese et al. 2009 to this class.Publication:
Wiese J, Thiel V, Gartner A, Schmaljohann R, Imhoff JF. Kiloniella laminariae gen. nov., sp. nov., an alphaproteobacterium from the marine macroalga Laminaria saccharina. Int J Syst Evol Microbiol 2009; 59:350-356.
🧒 Yilmaz et al. (2014) assigned the genus Breoghania Gallego et al. 2011 to this class.Publication:
Yilmaz P, Parfrey LW, Yarza P, Gerken J, Pruesse E, Quast C, Schweer T, Peplies J, Ludwig W, Glöckner FO. The SILVA and “all-species living tree project (LTP)” taxonomic frameworks. Nucleic Acids Research 2014; 42(D1):D643-D648.
🧒 Yilmaz et al. (2014) assigned the genus Geminicoccus Foesel et al. 2008 to this class.Publication:
Yilmaz P, Parfrey LW, Yarza P, Gerken J, Pruesse E, Quast C, Schweer T, Peplies J, Ludwig W, Glöckner FO. The SILVA and “all-species living tree project (LTP)” taxonomic frameworks. Nucleic Acids Research 2014; 42(D1):D643-D648.
🧒 Yilmaz et al. (2014) assigned the genus Rhizomicrobium Ueki et al. 2010 to this class.Publication:
Yilmaz P, Parfrey LW, Yarza P, Gerken J, Pruesse E, Quast C, Schweer T, Peplies J, Ludwig W, Glöckner FO. The SILVA and “all-species living tree project (LTP)” taxonomic frameworks. Nucleic Acids Research 2014; 42(D1):D643-D648.
🧒 Yilmaz et al. (2014) assigned the genus Eilatimonas Paramasivam et al. 2013 to this class.Publication:
Yilmaz P, Parfrey LW, Yarza P, Gerken J, Pruesse E, Quast C, Schweer T, Peplies J, Ludwig W, Glöckner FO. The SILVA and “all-species living tree project (LTP)” taxonomic frameworks. Nucleic Acids Research 2014; 42(D1):D643-D648.
🚃 The type genus of this class has alternatively been placed in the class Alphabacteria Cavalier-Smith 2002.Publication:
Cavalier-Smith T. The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification. Int J Syst Evol Microbiol 2002; 52:7-76.
🙄 This taxon name is occasionally misprinted (or affected by an OCR error) in some sources as: "Alfaproteobacteria"; "Alphaflroteobacteria"; "Alphaprobacteria"; "Alphaprotebacteria"; "Alphaproteobacetria"; "Alphaproteobacte"; "Alphaproteobactera"; "Alphaproteocbacteria"; "Alphaprotobacteria"; "Alphaprouobacteria"; "Alpharoteobacteria"; "Alpharproteobacteria"; "Alphproteobacteria"; "Alpthaproteobacteria"; "Aphaproteobacteria"; "Lphaproteobacteria". — 🤨 This taxon name is occasionally used in singular form as: "Alphaproteobacterium".
🧔 This taxon was discussed in a meeting of a Taxonomic Subcommittee of the ICSP.Publication:
Mousavi SA, Young JPW. International Committee on Systematics of Prokaryotes, Subcommittee on the taxonomy of Rhizobia and Agrobacteria, minutes of the annual meeting by videoconference, 5 July 2021, followed by online discussion until 31 December 2021. Int J Syst Evol Microbiol 2022; 72:5453.
🎰 The BRCs most frequently used for deposits in this group are: DSM: 1826; KCTC: 1351; JCM: 1149; NBRC: 767; ATCC: 687; CIP: 481; CGMCC: 442; MCCC: 416; CCUG: 341; CECT: 254.
🧍 A genome-scale phylogenetic analysis of the class was conducted by Hördt et al. (2020).Publication:
Hordt A, Lopez MG, Meier-Kolthoff JP, Schleuning M, Weinhold LM, Tindall BJ, Gronow S, Kyrpides NC, Woyke T, Goker M. Analysis of 1,000+ Type-Strain Genomes Substantially Improves Taxonomic Classification of Alphaproteobacteria. Front Microbiol 2020; 11:468.
🧍 Irregularly formed name (not formed from the stem of the name of the nomenclatural type).Publication:
Oren A, Arahal DR, Goker M, Moore ERB, Rossello-Mora R, Sutcliffe IC. International Code of Nomenclature of Prokaryotes. Prokaryotic Code (2022 Revision). Int J Syst Evol Microbiol 2023; 73:5585.
🧍 Nomenclatural type changed from Caulobacterales Henrici and Johnson 1935 (Approved Lists 1980) based on new Rule 22.Publication:
Oren A. Emendation of Rules 8, 15, 22, 25a, 30(3)(b), 30(4), 34a, and Appendix 7 of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2023; 73:6070.
🧍 This name was mentioned in a Request for an Opinion.Publication:
Oren A, Parte A, Garrity GM. Implementation of Rule 8 of the International Code of Nomenclature of Prokaryotes for the renaming of classes. Request for an Opinion. Int J Syst Evol Microbiol 2016; 66:4296-4298.
🧍 This name was mentioned in a Request for an Opinion. Rule 8 of the 2022 revision of the ICNP does not require that the name of a class validly published before 1 January 2012 be formed from the stem of the name of the type genus of the type order of the class plus the ending ia. This class name is orthographically correct (nominative plural noun, not formed from the name of the nomenclatural type).Publication:
Goker M. Solving the remaining problems with names of classes. Request for an Opinion. Int J Syst Evol Microbiol 2022; 72:5605.
Subdivision:
Number of child taxa with a validly published and correct name: 17 Number of child taxa with a validly published name, including synonyms: 33 Total number of child taxa: 41