List of bacterial orders


This article lists the orders of the Bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature and National Center for Biotechnology Information
and the phylogeny is based on 16S rRNA-based LTP release 132 by The All-Species Living Tree Project.

Phylogeny

National Center for Biotechnology Information taxonomy was initially used to decorate the genome tree via tax2tree. The 16S rRNA-based Greengenes taxonomy is used to supplement the taxonomy particularly in regions of the tree with no cultured representatives. List of Prokaryotic names with Standing in Nomenclature is used as the primary taxonomic authority for establishing naming priorities. Taxonomic ranks are normalised using phylorank and the taxonomy manually curated to remove polyphyletic groups.
Cladogram was taken from GTDB release 10-RS226.

Kingdom Bacillati">Terrabacteria">Bacillati

Phylum [Chloroflexota]

  • Class "Bathosphaeria" Mehrshad et al. 2018
  • * ?"Bathosphaerales" Mehrshad et al. 2018
  • Class "Martimicrobia" Williams et al. 2024
  • * ?"Martimicrobiales" Williams et al. 2024
  • Class "Poriflexia" Kogawa et al. 2022
  • * ?"Ca. Poriflexus" Kogawa et al. 2022
  • Class "Spiritibacteria" Williams et al. 2024
  • * ?"Spiritibacterales" Williams et al. 2024
  • Class "Tarhunnaeia" Williams et al. 2024
  • * ?"Tarhunnaeales" Williams et al. 2024
  • Class "Uliximicrobia" Williams et al. 2024
  • * ?"Uliximicrobiales" Williams et al. 2024
  • Class "Umbricyclopia" Mehrshad et al. 2018
  • * ?"Umbricyclopales" Mehrshad et al. 2018
  • Class "Dormiibacteria" Montgomery et al. 2021
  • * "Aeolococcales" Montgomery et al. 2021
  • * "Dormibacterales" Montgomery et al. 2021
  • Class "Limnocylindria" Mehrshad et al. 2018
  • * "Limnocylindrales" Mehrshad et al. 2018
  • Class Ktedobacteria corrig. Cavaletti et al. 2007
  • * Ktedobacterales corrig. Cavaletti et al. 2007
  • Class Chloroflexia Gupta et al. 2013
  • * Chloroflexales Gupta et al. 2013
  • * "Chloroheliales" Tsuji et al. 2024
  • * "Thermobaculales" Chuvochina et al. 2023
  • * Thermomicrobiales Garrity & Holt 2002
  • Class Dehalococcoidia Löffler et al. 2013
  • * "Australimonadales" Prabhu et al. 2024
  • * Dehalococcoidales Löffler et al. 2013
  • * "Lucifugimonadales" Lim et al. 2023
  • * "Monstramariales" Landry et al. 2017
  • * Tepidiformales Kochetkova et al. 2020
  • Class "Caldilineia" Oren, Parte & Garrity 2016 ex Cavalier-Smith 2020
  • * Aggregatilineales Nakahara et al. 2019
  • * "Amarolineaceae" Andersen et al. 2019
  • * Anaerolineales Yamada et al. 2006
  • * Ardenticatenales Kawaichi et al. 2013
  • * Caldilineales Yamada et al. 2006
  • * "Epilineales" Petriglieri et al. 2023
  • * "Roseilineaceae" Ward et al. 2021
  • * "Promineifilales" corrig. Chuvochina et al. 2023
  • * Thermoflexales Dodsworth et al. 2014

Phylum [Actinomycetota]

Phylum "[Sysuimicrobiota]"

  • Class "Sysuimicrobiia" Liu et al. 2024
  • * "Sysuimicrobiales" Liu et al. 2024

Phylum [Armatimonadota]

  • Class "Zipacnadia" Carlton et al. 2023
  • * "Zipacnadales" Carlton et al. 2023
  • Class Abditibacteriia Tahon et al. 2018
  • * Abditibacteriales Tahon et al. 2018
  • Class Fervidibacteria Nou et al. 2025
  • * Fervidibacterales Nou et al. 2025
  • Class "Heboniibacteriia" corrig. Carlton et al. 2023
  • * "Heboniibacterales" corrig. Carlton et al. 2023
  • Class UBA5829
  • * "Candidatus Hippobium" Gilroy et al. 2022
  • Class Fimbriimonadia Im et al. 2012
  • * Fimbriimonadales Im et al. 2012
  • Class Chthonomonadia Oren, Parte & Garrity 2016
  • * Chthonomonadales Lee et al. 2011
  • Class Armatimonadia Tamaki et al. 2011
  • * Armatimonadales Tamaki et al. 2011

Phylum [Vulcanimicrobiota]

  • Class "Eudoremicrobiia" Paoli et al. 2022
  • * ?"Eudoremicrobiales" Paoli et al. 2022
  • Class "Xenobia" Ji et al. 2021
  • * "Xenobiales" Ji et al. 2021
  • Class Vulcanimicrobiia Yabe et al. 2024
  • * "Eremiobacterales" Ward, Cardona & Holland-Moritz 2019
  • * Vulcanimicrobiales Yabe et al. 2024

Phylum [Bacillota]

Firmicutes incertae sedis

  • Class Desulfitisporia Sorokin & Merkel 2023
  • * Desulfitisporales Sorokin & Merkel 2023
  • Class Thermolithobacteria Sokolova et al. 2007
  • * Thermolithobacterales Sokolova et al. 2007

Clade Bacillota G

  • Class Limnochordia Watanabe, Kojima & Fukui 2015
  • * Limnochordales Watanabe, Kojima & Fukui 2015
  • Class "Hydrogenisporia" Pallen, Rodriguez-R & Alikhan 2022
  • * "Capillibacteriales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Hydrogenisporales" Pallen, Rodriguez-R & Alikhan 2022

Clade Bacillota E

  • Class UBA3575
  • * "Candidatus Acetocimmeria" Smith et al. 2021
  • Class Thermaerobacteria Chuvochina et al. 2024
  • * Thermaerobacterales Chuvochina et al. 2024
  • Class Symbiobacteriia Chuvochina et al. 2024
  • * Symbiobacteriales Chuvochina et al. 2024
  • Class "Fermentithermobacillia" Kadnikov et al. 2023
  • * "Fermentithermobacillales" Kadnikov et al. 2023
  • Class Sulfobacillia Chuvochina et al. 2024
  • * Sulfobacillales Chuvochina et al. 2024

Clade "Selenobacteria"

  • Class Selenomonadia Oren, Parte & Garrity 2016
  • * Acidaminococcales Campbell, Adeolu & Gupta 2015
  • * Anaeromusales Chuvochina et al. 2024
  • * Anaerosinus Strompl et al. 1999
  • * "Azotosporobacter" Xie et al. 2024
  • * "Dendrosporobacterales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Massilibacillaceae"
  • * Pelorhabdus Grässle et al. 2022
  • * "Pelosinaceae"
  • * Propionisporales Chuvochina et al. 2024
  • * Selenomonadales Marchandin et al. 2010
  • * "Sporomusales" Cavalier-Smith 2006
  • * Veillonellales Campbell, Adeolu & Gupta 2015

Clade "[Desulfotomaculota]"

  • Class Peptococcia Chuvochina et al. 2024
  • * Peptococcales Chuvochina et al. 2024
  • * "Thermanaerosceptrales" Pallen, Rodriguez-R & Alikhan 2022
  • Class "Thermacetogeniia" corrig. Voyron et al. 2022
  • * Thermacetogeniales Chuvochina et al. 2024
  • Class Syntrophomonadia Chuvochina et al. 2024
  • * Syntrophomonadales Chuvochina et al. 2024
  • Class DSM-16504
  • * Desulfitibacterales Chuvochina et al. 2024
  • Class KKC1
  • * Calderihabitantales Chuvochina et al. 2024
  • Class JADQBR01
  • * "Metallumcola" Hsu et al. 2024
  • Class DULZ01
  • * Zhaonellaceae Lv et al. 2020
  • Class "Moorellia" Sorokin et al. 2020
  • * Neomoorellales Gtari & Ventura 2025
  • Class "Dehalobacteriia"
  • * "Avidehalobacterales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Cryptoclostridiales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Dehalobacteriales"
  • Class Desulfitobacteriia Chuvochina et al. 2024
  • * Desulfitobacteriales Chuvochina et al. 2024
  • * "Heliobacteriales" Kinman 1994 ex Cavalier-Smith 2020
  • Class "Carboxydocellia" Pallen, Rodriguez-R & Alikhan 2022
  • * "Carboxydocellales Chuvochina et al. 2024
  • Class Thermincolia Chuvochina et al. 2024
  • * "Thermincolales Chuvochina et al. 2024
  • Class "Carboxydothermia" Pallen, Rodriguez-R & Alikhan 2022
  • * Carboxydothermales Chuvochina et al. 2024
  • Class Desulfotomaculia Chuvochina et al. 2024
  • * Ammonificales corrig. Chuvochina et al. 2024
  • * Desulfotomaculales Chuvochina et al. 2024

Clade "Halanaerobiota">Halanaerobiales">Halanaerobiota"

  • Class "Halanaerobiia" Cavalier-Smith 2020
  • * "Anoxybacterales" Pallen, Rodriguez-R & Alikhan 2022
  • * Halanaerobiales corrig. Rainey & Zhilina 1995
  • * Halobacteroidales Chuvochina et al. 2024

Clade "Clostridiota"

  • Class Thermosediminibacteria Chuvochina et al. 2024
  • * Koleobacterales Sakamoto et al. 2021
  • * Thermosediminibacterales Zhang et al. 2019
  • Class "Thermoanaerobacteria" Sorokin et al. 2020
  • * Caldicellulosiruptorales Chuvochina et al. 2024
  • * Thermoanaerobacterales Wiegel 2010
  • Class "Clostridiia" Oren, Parte & Garrity 2016
  • * Acetivibrionales Chuvochina et al. 2024
  • * "Avimonoglobales" Pallen, Rodriguez-R & Alikhan 2022
  • * Caldicoprobacterales Chuvochina et al. 2024
  • * Christensenellales Parks et al. 2018 ex Chuvochina et al. 2024
  • * Clostridiales Prevot 1953 s.s.
  • * ?"Darwinibacteriales" Puchol-Royo et al. 2023
  • * "Egerieisomatales" Pallen, Rodriguez-R & Alikhan 2022
  • * Eubacteriales Buchanan 1917
  • * Lachnospirales Chuvochina et al. 2024
  • * Lutisporales Chuvochina et al. 2024
  • * Mahellales Chuvochina et al. 2024
  • * "Merdicolales" Pallen, Rodriguez-R & Alikhan 2022
  • * Monoglobales Chuvochina et al. 2024
  • * "Oscillospirales" Glendinning et al. 2020
  • * "Petroclostridiales" Pallen, Rodriguez-R & Alikhan 2022
  • * Peptostreptococcales Chuvochina et al. 2024
  • * "Qingrenia" Liu et al. 2021b
  • * "Saccharofermentanales" corrig. Parks et al. 2018
  • * "Thermoclostridiaceae" Pallen, Rodriguez-R & Alikhan 2022
  • * Tissierellales Alauzet et al. 2020

Clade Bacillota D

  • Class "Proteinivoracia"
  • * "Proteinivoracales"
  • Class Dethiobacteria Sorokin & Merkel 2025
  • * "Candidatus Contubernalis" corrig. Zhilina et al. 2005
  • * Dethiobacterales Sorokin & Merkel 2025
  • Class Natranaerobiia Chuvochina et al. 2024
  • * Natranaerobiales Mesbah et al. 2007

Clade [Bacillota]

  • Class "Bacillia" Cavalier-Smith 2020
  • * Alicyclobacillales Chuvochina et al. 2024
  • * Aneurinibacillales Chuvochina et al. 2024
  • * Aureibacillaceae Li et al. 2024
  • * "Bacillidae" Cavalier-Smith 2020 non Enderlein 1917
  • ** Bacillales_C
  • ** Bacillales_D
  • ** Bacillales_E
  • ** Bacillales_G
  • ** Bacillales_H
  • ** Bacillus marinisedimentorum Guo et al. 2018
  • ** Bacillales Prevot 1953 s.s.
  • ** "Caldibacillales"
  • ** Sporolactobacillaceae Ludwig et al. 2010
  • * "Bacillus thermozeamaize" Mak 2003
  • * Brevibacillales Chuvochina et al. 2024
  • * Caldalkalibacillales Chuvochina et al. 2024
  • * Calditerricolales Chuvochina et al. 2024
  • * Desulfuribacillales Sorokin et al. 2021
  • * "Erysipelotrichidae" corrig. Cavalier-Smith 2020
  • ** Acholeplasmatales Freundt et al. 1984
  • ** "Aphodocolales" Pallen, Rodriguez-R & Alikhan 2022
  • ** "Bathyoplasmales" corrig. Zhu, Lian & He 2020
  • ** "Caccosomales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Culicoidibacterales Neupane et al. 2020
  • ** Erysipelotrichales Ludwig et al. 2010
  • ** Haloplasmatales Rainey et al. 2008 non Zhou et al. 2022
  • ** "Izemoplasmatales" corrig. Zheng et al. 2021
  • ** ?"Liberiplasmatales" Khomyakova et al. 2025
  • ** Mycoplasmatales Freundt 1955
  • ** Turicibacteraceae Verbarg et al. 2020
  • * Exiguobacteriales Chuvochina et al. 2024
  • * "Harrysmithimonadales" Pallen, Rodriguez-R & Alikhan 2022
  • * Kyrpidiales Chuvochina et al. 2024
  • * Lactobacillales Ludwig, Schleifer & Whitman 2010
  • * Microaerobacter Khelifi et al. 2011
  • * Paenibacillales Chuvochina et al. 2024
  • * Planococcaceae Peshkoff 1939
  • * "Rubeoparvulales"
  • * Staphylococcales Chuvochina et al. 2024
  • * Tepidibacillales Chuvochina et al. 2024
  • * Thermicanales Chuvochina et al. 2024
  • * Thermoactinomycetales Chuvochina et al. 2024
  • * Tumebacillales Chuvochina et al. 2024

Clade Cyanoprokaryota

Phylum "[Margulisiibacteriota]"

  • Class "Saganbacteria" Carnevali et al. 2018
  • Class "Marinamargulisbacteria" Carnevali et al. 2019
  • Class "Riflemargulisbacteria" Carnevali et al. 2019
  • Class "Termititenacia" Utami et al. 2019
  • * "Termititenacales" Utami et al. 2019

Phylum "Cyanobacteriota">Cyanobacteria">Cyanobacteriota"

  • Class "Sericytochromatia" Soo et al. 2017
  • * S15B-MN24
  • * UBA7694
  • Class Vampirovibrionia Chuvochina et al. 2024
  • * "Caenarcaniphilales" Soo et al. 2014
  • * "Gastranaerophilales" Di Rienzi et al. 2013
  • * "Obscuribacterales" Soo et al. 2014
  • * Vampirovibrionales Chuvochina et al. 2024
  • Class Gloeobacteria Cavalier-Smith 2002
  • * Gloeobacterales Cavalier-Smith 2002
  • Class Phycobacteria Cavalier-Smith 2002
  • * Acaryochloridales Miyashita et al. 2003 ex Strunecký & Mareš 2022
  • * ?Aegeococcales Strunecký & Mareš 2022
  • * Trichothermofontia Daroch et al. 2023
  • * Cyanobacteriales Rippka & Cohen-Bazire 1983
  • * ?"Eurycoccales"
  • * ?Geitlerinematales Strunecký & Mareš 2022
  • * Gloeoemargaritales Moreira et al. 2016
  • * Leptolyngbyales Strunecký & Mareš 2022
  • * ?"Limnotrichales" Trebuch et al. 2020
  • * Neosynechococcales Chuvochina et al. 2024
  • * Nodosilineales Strunecký & Mareš 2022
  • * Oculatellales Strunecký & Mareš 2022
  • * Prochlorococcaceae Komárek & Strunecky 2020
  • * Prochlorotrichales Strunecký & Mareš 2022
  • * Pseudanabenales Hoffmann, Komárek & Kastovsky 2005
  • * ?"Pseudophormidiales"
  • * Romeriopsis Hentschke et al. 2022
  • * Synechococcales Hoffmann, Komárek & Kastovsky 2005
  • * Thermostichales Komárek & Strunecký 2020
  • * Trichocoleaceae Mai & Johansen 2018 non Nakai

Kingdom [Thermotogati]

Phylum [Atribacterota]

  • Class Atribacteria Katayama et al. 2021
  • * Atribacterales Katayama et al. 2021
  • Class "Phoenicimicrobiia" Jiao et al. 2024
  • * "Phoenicimicrobiales" Jiao et al. 2024

Phylum [Synergistota]

Phylum Dictyoglomerota">Dictyoglomota">Dictyoglomerota

Phylum [Thermodesulfobiota]

  • Class "Thermodesulfobiia" Frolov et al. 2023
  • * "Thermodesulfobiales" Cavalier-Smith 2023

Phylum [Coprothermobacterota]

Phylum "[Lithacetigenota]"

  • Class HKB111
  • * "Candidatus Lithacetigena" Nobu et al. 2022

Phylum [Caldisericota]

Phylum [Thermotogota]

  • Class "Thermotogia" Oren, Parte & Garrity 2016 ex Cavalier-Smith 2020
  • * Mesoaciditogales Itoh et al. 2016
  • * Petrotogales Bhandari & Gupta 2014
  • * Thermotogales Reysenbach 2002 emend. Bhandari & Gupta 2014

Phylum "[Bipolaricaulota]"

  • Class "Bipolaricaulia" Chuvochina et al. 2023
  • * "Bipolaricaulales" Chuvochina et al. 2023
  • * "Fraserbacterales"

Phylum [Fusobacteriota]

  • Class Fusobacteriia corrig. Staley & Whitman 2012
  • * Fusobacterales Staley & Whitman 2012

Clade [Candidate Phyla Radiation]

Phylum "Elulimicrobiota">Elulota">Elulimicrobiota"

  • Class "Elulimicrobiia" Rodriguez-R et al. 2020
  • * ?"Elulimicrobiales" Rodriguez-R et al. 2020

Phylum [Minisyncoccota]

  • Class "Wirthbacteria"
  • Class "Dojkabacteria"
  • Class "Katanobacteria"
  • Class "Microgenomatia"
  • * Clade GWA2-44-7
  • * "Chazhemtobacteriales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Curtissbacterales"
  • * "Daviesbacterales"
  • * "Gottesmanbacterales"
  • * "Levybacterales"
  • * "Roizmanbacterales"
  • * "Shapirobacterales"
  • * "Woykebacterales"
  • Class "Absconditabacteria"
  • * "Absconditabacterales" Yakimov et al. 2022
  • * "Candidatus Altimarinus" Rinke et al. 2013
  • Class "Gracilibacteria"
  • * "Abawacabacterales"
  • * "Fertabacterales"
  • * "Peregrinibacterales"
  • * "Peribacterales" Anantharaman et al. 2016
  • Class "Berkelbacteria"
  • Class "Kazanbacteria"
  • Class "Howlettbacteria"
  • Class "Saccharimonadia" corrig. Lemos et al. 2019
  • * "Saccharimonadales" corrig. Lemos et al. 2019 ex Chuvochina et al. 2023
  • Class ?"Baikalibacteria" Haro-Moreno et al. 2023
  • Class "Andersenbacteria"
  • Class "Doudnabacteria"
  • Class "Torokbacteria"
  • Class "Patescibacteriia" Dutkiewicz et al. 2025
  • * ?"Brownbacterales"
  • * "Buchananbacterales"
  • * "Falkowbacterales"
  • * "Jacksonbacterales"
  • * "Kerfeldbacterales"
  • * "Komeilibacterales"
  • * "Kuenenbacterales"
  • * "Magasanikbacterales"
  • * "Moisslbacterales"
  • * "Patescibacteriales" Dutkiewicz et al. 2025
  • * "Uhrbacterales"
  • * "Veblenbacterales"
  • Class Minisyncoccia Nakajima et al. 2025
  • * Clade UBA6257
  • * "Azambacterales"
  • * "Giovannonibacteraceae"
  • * ?"Montesolbacterales"
  • * "Moranbacterales"
  • * "Niyogibacteraceae"
  • * Minisyncoccales Nakajima et al. 2025
  • * "Parcunitrobacterales" Castelle et al. 2017
  • * "Portnoybacterales"
  • * "Ryanbacterales"
  • * "Spechtbacterales"
  • * "Sungbacterales"
  • * "Tagabacterales"
  • * "Terrybacteraceae"
  • * "Yanofskybacterales"

Clade

Phylum [Deinococcota]

Kingdom Pseudomonadati">Hydrobacteria">Pseudomonadati

Incertae sedis

Phylum "[Muiribacteriota]"

  • Class "Muiribacteriia" corrig. Chuvochina et al. 2023
  • * "Muiribacteriales" corrig. Chuvochina et al. 2023
  • Class "Ozemibacteria" corrig. Kadnikov et al. 2018
  • * "Ozemibacterales" corrig. Kadnikov et al. 2018
  • Class "Wallbacteriia"

Phylum "[Macinerneyibacteriota]"

  • Class "Macinerneyibacteriia" corrig. Yadav et al. 2020
  • * "Macinerneyibacteriales" corrig. Yadav et al. 2020

Phylum "[Babelota]"

  • Class "Babeliae" Yeoh et al. 2016
  • * "Babelales" corrig. Yeoh et al. 2016

Phylum [Campylobacterota]

Phylum [Spirochaetota]

  • Class Leptospiria Chuvochina et al. 2024
  • * Leptospirales corrig. Gupta et al. 2014
  • * Turneriellales Chuvochina et al. 2024
  • Class Brevinematia Chuvochina et al. 2024
  • * Brevinematales Gupta et al. 2014
  • Class Brachyspiria Chuvochina et al. 2024
  • * Brachyspirales corrig. Gupta et al. 2014
  • Class "Exilispiria" Pallen, Rodriguez-R & Alikhan 2022
  • * "Exilispirales" Pallen, Rodriguez-R & Alikhan 2022
  • Class Spirochaetia Paster 2020
  • * ?Spirochaetales Buchanan 1917
  • * Borreliales Chuvochina et al. 2024
  • * Spirochaeta cellobiosiphila Breznak & Warnecke 2008
  • * "Entomospirales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Candidatus Haliotispira" Sharma et al. 2024
  • * "Marispirochaetales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Salinispirales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Sediminispirochaetales" Pallen, Rodriguez-R & Alikhan 2022
  • * Sphaerochaetales Chuvochina et al. 2024
  • * Spirochaetales_E
  • * "Candidatus Thalassospirochaeta" Pragya et al. 2024
  • * Treponematales Chuvochina et al. 2024
  • * "Winmispirales" Podosokorskaya et al. 2025

Phylum "[Goldiibacteriota]"

  • "Candidatus Cellulosimonas" Doud et al. 2020

Phylum "[Ryujiniota]"

  • Class "Ryujiniia" Sun et al. 2025
  • * "Ryujiniales" Sun et al. 2025

Phylum [Elusimicrobiota]

  • Class "Elusimicrobiia" Oren, Parte & Garrity 2016 ex Cavalier-Smith 2020
  • * Elusimicrobiales Geissinger et al. 2010
  • * "Obscuribacteriales" Uzun et al. 2023
  • Class "Endomicrobiia" Stingl et al. 2018
  • * "Endomicrobiales" Zheng et al. 2018

Phylum "[Aerophobota]"

  • Class "Aerophobia" Chuvochina et al. 2023
  • * "Aerophobales" Chuvochina et al. 2023

Phylum "[Omnitrophota]"

  • Class "Omnitrophia"
  • * "Omnitrophales"
  • Class "Velamenicoccia" Pallen, Rodriguez-R & Alikhan 2022
  • * "Aquitaenarimonadales" Seymour et al. 2022
  • * "Aquiviventales" Seymour et al. 2022
  • * "Duberdicusellales" Seymour et al. 2022
  • * "Ghiorseimicrobiales" Seymour et al. 2022
  • * "Gorgyraeales" Seymour et al. 2023
  • * "Gygaeellales" Seymour et al. 2023
  • * "Kaelpiales" Seymour et al. 2022
  • * "Kappaeales" Seymour et al. 2022
  • * ?"Candidatus Orphnella" Williams et al. 2021
  • * "Pluralincolimonadales" Seymour et al. 2022
  • * "Taenaricolales" Seymour et al. 2022
  • * "Tantalellales" Seymour et al. 2022
  • * "Velamenicoccales" Pallen, Rodriguez-R & Alikhan 2022
  • * "Velesiimonadales" Seymour et al. 2022
  • * "Zapsychrales" Seymour et al. 2022

Phylum "[Fidelibacterota]"

  • ?"Candidatus Neomarinimicrobium" Rinke et al. 2013 corrig. Oren et al. 2020
  • Class Fidelibacteria Katayama et al. 2024
  • * Fidelibacterales Katayama et al. 2024

Phylum "[Heilongiota]"

  • Class "Heilongiia" corrig. Zhang et al. 2022
  • * ?"Heilongiales" Zhang et al. 2022

Phylum "[Saltatorellota]"

  • Class "Saltatorellae" Wiegand et al. 2019
  • * ?"Saltatorellales" Wiegand et al. 2019

Phylum "[Tianyaibacteriota]"

  • ?"Candidatus Tianyaibacterium" corrig. Cui et al. 2021

Phylum "[Hinthialibacterota]"

  • Class "Hinthialibacteria" Williams et al. 2022
  • * "Hinthialibacterales" Williams et al. 2022

Phylum "[Sumerlaeota]"

  • Class "Sumerlaeia" Kadnikov et al. 2018
  • * "Sumerlaeales" Kadnikov et al. 2018

Phylum "[Poribacteriota]"

  • Class ?"Entoporibacteria" Podell et al. 2019
  • Class ?"Pelagiporibacteria" Podell et al. 2019

Phylum "[Hydrogenedentota]"

  • Class "Hydrogenedentia" Chuvochina et al. 2023
  • * "Hydrogenedentales" corrig. Chuvochina et al. 2023

Clade [Planctobacteria]

Phylum [Planctomycetota]

Phylum "[Auribacterota]"

  • Class "Ancaeobacteria" Williams et al. 2022
  • * "Ancaeobacterales" Williams et al. 2022
  • Class "Auribacteria" Williams et al. 2022
  • * "Auribacterales" Williams et al. 2022
  • Class "Erginobacteria" Williams et al. 2022
  • * "Erginobacterales" Williams et al. 2022
  • Class JACPWU01
  • * "Theseobacterales" Williams et al. 2022
  • Class "Tritonobacteria" Williams et al. 2022
  • * "Tritonobacterales" Williams et al. 2022

Phylum [Chlamydiota]

  • Class Chlamydiia Horn 2011
  • * "Similichlamydiales" Pallen, Rodriguez-R & Alikhan 2022
  • * Chlamydiales Storz & Page 1971 em. Everett et al. 1999

Phylum [Verrucomicrobiota]

  • Class Lentisphaeria Cho et al. 2004
  • * Lentisphaerales Cho et al. 2004
  • * Oligosphaerales Qiu et al. 2013
  • * Victivallales Cho et al. 2004
  • Class Kiritimatiellae Spring et al. 2017
  • * Kiritimatiellales Spring et al. 2017
  • * "Spyradenecales" Pallen, Rodriguez-R & Alikhan 2022
  • Class Verrucomicrobiia corrig. Hedlund, Gosink & Staley 1998
  • * Limisphaerales Podosokorskaya et al. 2023
  • * Methylacidiphilales Awala et al. 2023
  • * Opitutales Choo et al. 2007
  • * Terrimicrobiales García-López et al. 2020
  • * Verrucomicrobiales Ward-Rainey et al. 1996 em. Yoon et al. 2008

Clade [FCB group]

Phylum "[Tangaroaeota]"

  • Class "Tangaroaeia" Sun et al. 2025
  • * "Tangaroaeales" Sun et al. 2025

Phylum "[Latescibacterota]"

  • Class "Handelsmanbacteria"
  • Class "Latescibacteria" Chuvochina et al. 2023
  • * "Latescibacterales" Chuvochina et al. 2023

Phylum "[Fermentibacterota]"

  • Class "Fermentibacteria" Kirkegaard 2016
  • * "Fermentibacterales" Kirkegaard 2016

Phylum "[Orphanbacterota]"

  • Class "Orphanbacteria" Gong et al. 2022
  • * "Orphanbacterales" Gong et al. 2022

Phylum "[Arandabacterota]"

  • Class "Arandabacteria" Gong et al. 2022
  • * "Arandabacterales" Gong et al. 2022

Phylum "[Joyebacterota]"

  • Class "Joyebacteria" Gong et al. 2022
  • * "Joyebacterales" Gong et al. 2022

Phylum "[Krumholzibacteriota]"

  • Class "Krumholzibacteriia" corrig. Youssef et al. 2019
  • * "Delphibacterales"
  • * "Krumholzibacteriales" Youssef et al. 2019

Phylum "[Blakebacterota]"

  • Class "Blakebacteria" Gong et al. 2022
  • * "Blakebacterales" Gong et al. 2022

Phylum [Gemmatimonadota]

  • Class "Glassbacteria"
  • Class Gemmatimonadetes Zhang et al. 2003
  • * ?Gaopeijiales Ye et al. 2025
  • * Gemmatimonadales Zhang et al. 2003
  • * Longimicrobiales Pascual et al. 2016
  • * "Palaucibacterales" Aldeguer-Riquelme, Antón & Santos 2022

Phylum "[Hydrothermota]"

  • Class "Tepidihabitantia" Slobodkina et al. 2025
  • * ?"Tepidihabitantales" Slobodkina et al. 2025
  • Class "Stahliibacteriia"
  • Class "Hydrothermia" Chuvochina et al. 2019 ex Chuvochina et al. 2023
  • * "Hydrothermales" Chuvochina et al. 2019 ex Chuvochina et al. 2023
  • * "Caldipriscales" Pallen, Rodriguez-R & Alikhan 2022

Phylum "[Cloacimonadota]"

  • Class "Cloacimonadia" Williams et al. 2021 ex Chuvochina et al. 2023
  • * "Candidatus Celaenobacter" Williams et al. 2021
  • * "Cloacimonadales" Williams et al. 2021 ex Chuvochina et al. 2023

Phylum [Fibrobacterota]

  • Class "Raymondbacteria"
  • Class Chitinivibrionia Sorokin et al. 2014
  • * Chitinivibrionales Sorokin et al. 2014
  • Class Fibrobacteria Spain et al. 2012
  • * Fibrobacterales Spain et al. 2012

Phylum "[Marinisomatota]"

  • Class "Marinisomatia"
  • * "Marinisomatales"

Phylum [Calditrichota]

  • Class Calditrichia Kublanov et al. 2022
  • * Calditrichales Kublanov et al. 2020

Phylum "[Zhuqueibacterota]"

  • Class "Cosmopoliia" corrig. Zhang et al. 2023
  • * "Cosmopoliales" Zhang et al. 2023
  • Class "Zhuqueibacteria" Lian et al. 2024
  • * "Oceanimicrobiales" Lian et al. 2024
  • * "Oleimicrobiales" Lian et al. 2024
  • * "Residuimicrobiales" Lian et al. 2024
  • * "Sulfurfontimicrobiaceae" Lian et al. 2024
  • * "Thermofontimicrobiales" Lian et al. 2024
  • * "Zhuqueibacterales" Lian et al. 2024

Phylum "[Effluvivivacota]"

  • Family "Effluvivivacaceae" corrig. Su et al. 2024

Phylum [Bacteroidota]_A

  • Class "Kapaibacteriia" corrig. Chuvochina et al. 2023
  • * "Kapaibacteriales" corrig. Chuvochina et al. 2023
  • Class "Kryptonia"
  • * "Kryptoniales"
  • Class "Ignavibacteriia" Oren, Parte & Garrity 2016 ex Cavalier-Smith 2022
  • * Ignavibacteriales Iino et al. 2010
  • * "Tepidaquicellales" corrig. Kadnikov et al. 2020
  • Class Chlorobiia Oren, Parte & Garrity 2016 ex Cavalier-Smith 2020
  • * Chlorobiales Gibbons & Murray 1978
  • Class Rhodothermia Munoz, Rossello-Mora & Amann 2017
  • * Balneolales Munoz, Rossello-Mora & Amann 2017
  • * Rhodothermales Munoz, Rossello-Mora & Amann 2017

Phylum "[Electryoneota]"

  • Class "Electryoneia" Williams et al. 2022
  • * Electryoneales Williams et al. 2022
  • Class AABM5-125-24
  • * Hatepunaeales Williams et al. 2022
  • Class "Tariuqbacteria" Vigneron, Vincent & Lovejoy 2023
  • * Tariuqbacterales Vigneron, Vincent & Lovejoy 2023

Phylum [Bacteroidota]

Clade [Proteobacteria]

Phylum "[Canglongiota]"

  • Class "Canglongiliia" Zhang et al. 2022
  • * ?"Canglongiales" Zhang et al. 2022

Phylum [Acidobacteriota]

Phylum [Bdellovibrionota]

Phylum Desulfobacterota G

  • Class Syntrophorhabdia Waite et al. 2020
  • * Syntrophorhabdales Waite et al. 2020

Phylum "Acidulodesulfobacteriota"

  • Class "Acidulodesulfobacteriia" Pallen, Rodriguez-R & Alikhan 2022
  • * "Acidulidesulfobacterales" corrig. Tan et al. 2019

Phylum "[Dadaibacteriota]"

  • Class "Dadabacteria" Hug et al. 2016
  • * "Nemesobacterales" Gavriilidou et al. 2023

Phylum "[Calescibacteriota]"

  • Class "Calescibacteriia" Chuvochina et al. 2023
  • * "Calescibacteriales" Chuvochina et al. 2023

Phylum [Thermosulfidibacterota]

  • Class Thermosulfidibacteria Cavalier-Smith 2020 ex Chuvochina et al. 2024
  • * Thermosulfidibacterales Cavalier-Smith 2020 ex Chuvochina et al. 2024

Phylum [Aquificota]

Phylum "[Deferrimicrobiota]"

  • Class "Deferrimicrobiia" corrig. Begmatov et al. 2022
  • * Deferrimicrobiales Begmatov et al. 2022

Phylum "[Deferrisomatota]"

Phylum "[Lernaellota]"

  • Class "Lernaellia" Williams et al. 2022
  • * "Alcyoniellaceae" Williams et al. 2022
  • * "Lernaellales" Williams et al. 2022

Phylum "[Binatota]"

  • Class "Binatia" Chuvochina et al. 2019 ex Chuvochina et al. 2023
  • * "Binatales" Chuvochina et al. 2019 ex Chuvochina et al. 2023

Phylum [Myxococcota]

  • Class "Kuafubacteriia" corrig. Li et al. 2023
  • * "Kuafubacteriales" Li et al. 2023
  • Class Myxococcia Waite et al. 2020
  • * Myxococcales Tchan, Pochon & Prévot 1948
  • Class Bradymonadia corrig. Chuvochina et al. 2024
  • * Bradymonadales Wang et al. 2015
  • Class Polyangiia corrig. Waite et al. 2020
  • * Haliangiales Waite et al. 2020
  • * Nannocystales Waite et al. 2020
  • * Polyangiales Tchan, Pochon & Prevot 1948

Phylum "[Nitrosediminicolota]"

  • ?Candidatus "Nitrosediminicola" Zhao, Jorgensen & Babbin 2024

Phylum "[Moduliflexota]"

  • Class "Moduliflexia" Sekiguchi et al. 2015
  • * "Moduliflexales" Sekiguchi et al. 2015

Phylum "[Spongiamicota]"

  • Class "Spongiamicia" Sun et al. 2025
  • * "Spongiamicales" Sun et al. 2025

Phylum "[Tectimicrobiota]"

  • Class "Entotheonellia" Chuvochina et al. 2023
  • * "Entotheonellales" Schmidt et al. 2000 ex Chuvochina et al. 2023

Phylum [Nitrospinota]

  • Class Nitrospinia Lucker et al. 2022
  • * Nitrospinales Lucker et al. 2022

Phylum "[Methylomirabilota]"

  • Class "Methylomirabilia" Chuvochina et al. 2023
  • * "Methylomirabilales" Cabrol et al. 2020 ex Chuvochina et al. 2023
  • * "Rokubacteriales"

Phylum [Nitrospirota]

  • Class Thermodesulfovibrionia Umezawa et al. 2023
  • * ?"Mariimomonadales" Yoon et al. 2023
  • * Thermodesulfovibrionales Umezawa et al. 2023
  • Class Nitrospiria Garrity & Holt 2022
  • * Nitrospirales Garrity & Holt 2022
  • * "Troglogloeales" Yu et al. 2022

Phylum [Thermodesulfobacteriota]

  • Class "Zymogeniia" corrig. Murphy et al. 2021
  • * "Zymogeniales" Murphy et al. 2021
  • Class "Anaeroferrophilia" corrig. Murphy et al. 2021
  • * "Anaeroferrophilales" Murphy et al. 2021
  • Class Desulfuromonadia Waite et al. 2020
  • * Desulfuromonadales corrig. Kuever, Rainey & Widdel 2006
  • * Geobacterales Waite et al. 2020
  • Class Desulfomonilia Waite et al. 2020
  • * Desulfomonilales Waite et al. 2020
  • Class Syntrophia Waite et al. 2020
  • * Syntrophales Waite et al. 2020
  • Class Dissulfuribacteria Waite et al. 2020
  • * Dissulfuribacterales Waite et al. 2020
  • Class Thermodesulfobacteriia corrig. Hatchikian, Ollivier & Garcia 2002
  • * Thermodesulfobacteriales Hatchikian, Ollivier & Garcia 2002
  • Class Desulfobulbia Waite et al. 2020
  • * Desulfobulbales Waite et al. 2020
  • Class "Desulfofervidia" Waite et al. 2020
  • * "Desulfofervidales" Waite et al. 2020
  • Class "Desulfatiglandia" Pallen, Rodriguez-R & Alikhan 2022
  • * Desulfatiglandales Waite et al. 2020
  • Class Desulfobaccia Waite et al. 2020
  • * Desulfobaccales Waite et al. 2020
  • Class Desulfarculia Waite et al. 2020
  • * "Adiutricales" Waite et al. 2020
  • * Desulfarculales corrig. Kuever, Rainey & Widdel 2006
  • Class Syntrophobacteria Waite et al. 2020
  • * Syntrophobacterales Waite et al. 2020
  • Class Desulfobacteria Waite et al. 2020
  • * Desulfobacterales Kuever, Rainey & Widdel 2006

Phylum "[Leptospirillaeota]"

  • Class "Leptospirillia" Chuvochina et al. 2023
  • * "Leptospirillales" Chuvochina et al. 2023

Phylum "[Desulfovibrionota]"

Phylum SAR324

  • Class Lambdaproteobacteria Anantharaman et al. 2016

Phylum "[Oligoflexaeota]"

Phylum [Chrysiogenota]

Phylum [Pseudomonadota]

  • Class "Anaeropigmentatia" corrig. Murphy et al. 2021
  • * ?Anaeropigmentatales corrig. Murphy et al. 2021
  • Class Caulobacteria" Oren, Parte & Garrity 2016 ex Cavalier-Smith 2020
  • * ?"Methylospongiales" Podell et al. 2020
  • * Clade "Rhodobacteriae"
  • ** Hyphomicrobiales Douglas 1957
  • ** "Pelagibacterales" Grote et al. 2012
  • ** Rhodobacterales Garrity, Bell & Lilburn 2006
  • * Sublass "Rickettsiidae" corrig. Ferla et al. 2013
  • ** "Enterousiales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Rickettsiales Gieszczykiewicz 1939 emend. Dumler et al. 2001
  • ** "Scatocolales" Pallen, Rodriguez-R & Alikhan 2022
  • * Sublass "Caulobacteridae" Ferla et al. 2013
  • ** Acetobacterales Chuvochina et al. 2024
  • ** Azospirillales Chuvochina et al. 2024
  • ** "Ca. Bealeia" Szokoli et al. 2016
  • ** "Ca. Bodonicaedibacter" corrig. Midha et al. 2021
  • ** Caulobacterales Henrici & Johnson 1935
  • ** "Caedimonadales"
  • ** Dongiales Chuvochina et al. 2024
  • ** Elsterales Chuvochina et al. 2024
  • ** Ferrovibrionales Chuvochina et al. 2024
  • ** "Futianiales" Liu et al. 2022
  • ** Geminicoccales Chuvochina et al. 2024
  • ** Holosporales Szokoli et al. 2016
  • ** "Inquilinales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Kiloniellales Wiese et al. 2009
  • ** "Marivibrionales" Pallen, Rodriguez-R & Alikhan 2022
  • ** "Methylospongiales" Podell et al. 2020
  • ** "Micavibrionales"
  • ** "Ca. Micropelagius" Jimenez-Infante et al. 2014
  • ** Micropepsales Harbison et al. 2016
  • ** Minwuiales Sun et al. 2018
  • ** Oceanibaculales Chuvochina et al. 2024
  • ** "Paracaedibacterales" Chuvochina et al. 2023
  • ** Parvibaculales Chuvochina et al. 2024
  • ** "Planktothermales" Zhou et al. 2020
  • ** Puniceispirillales Chuvochina et al. 2024
  • ** Pyruvatibacter Wang et al. 2016
  • ** Reyranellales Chuvochina et al. 2024
  • ** Rhodospirillales Pfennig & Truper 1971
  • ** Sphingomonadales Yabuuchi & Kosako 2006
  • ** Sneathiellales Kurahashi et al. 2008
  • ** Stellales Pallen, Rodriguez-R & Alikhan 2022
  • ** "Tagaeales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Thalassobaculales Chuvochina et al. 2024
  • ** Tistrellales Chuvochina et al. 2024
  • ** Zavarziniales Chuvochina et al. 2024
  • Class "Mariprofundia" Cavalier-Smith 2020
  • * Mariprofundales Makita et al. 2017
  • Class Magnetococcia Chuvochina et al. 2024
  • * Magnetococcales Bazylinski et al. 2013
  • Class Pseudomonadia" Oren, Parte & Garrity 2016
  • * ?"Ferritrophicales" Weiss et al. 2007
  • * ?"Kopriimonadales" Kwon et al. 2005c
  • * ?"Siderophilales" corrig. Corbera-Rubio et al. 2024
  • * ?"Spongiifermentales" Nguyen et al. 2023
  • * Thiohalorhabdales Sorokin & Merkel 2023
  • * Subclass "Acidithiobacillidae" Cavalier-Smith 2020
  • ** Acidithiobacillales Garrity, Bell & Lilburn 2005
  • * Subclass "Neisseriidae" Cavalier-Smith 2020
  • ** Burkholderiales Garrity, Bell & Lilburn 2006
  • ** "Tethybacterales" Taylor et al. 2021
  • * Subclass "Pseudomonadidae" Cavalier-Smith 2020
  • ** "Ca. Legionella polyplacis" Ríhová et al. 2017
  • ** Acidiferrobacterales Kojima, Shinohara & Fukui 2015
  • ** Acidihalobacteraceae Chuvochina et al. 2024
  • ** "Aquicellales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Arenicellales Teramoto, Yagyu & Nishijima 2015
  • ** "Azoamicaceae" Speth et al. 2023
  • ** Beggiatoales Buchanan 1957
  • ** "Berkiellales" Chuvochina et al. 2023
  • ** Cardiobacteriales Garrity, Bell & Lilburn 2005
  • ** Chromatiales Imhoff 2005
  • ** "Comchoanobacterales" Needham et al. 2022
  • ** "Competibacterales" Chuvochina et al. 2023
  • ** Coxiellales Chuvochina et al. 2024
  • ** Diplorickettsiales Chuvochina et al. 2024
  • ** Ectothiorhodospirales Chuvochina et al. 2024
  • ** Enterobacterales Adeolu et al. 2016
  • ** Enterobacteriaceae_A
  • ** "Foliamicales" Nguyen et al. 2023
  • ** Francisellales Chuvochina et al. 2024
  • ** Granulosicoccales Chuvochina et al. 2024
  • ** "Halofilales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Halothiobacillales Chuvochina et al. 2024
  • ** Immundisolibacterales Corteselli, Aitken & Singleton 2017
  • ** "Inmiraniales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Legionellales Garrity, Bell & Lilburn 2005
  • ** "Macondimonadales" Pallen, Rodriguez-R & Alikhan 2022
  • ** "Magnimaribacterales" Ramfelt et al. 2024
  • ** Methylococcales Bowman 2005
  • ** Methylohalomonadales Sorokin & Merkel 2023
  • ** Natronospirales Sorokin et al. 2025
  • ** Nevskiales Naushad et al. 2015
  • ** Nitrococcales Chuvochina et al. 2024
  • ** Nitrosococcales Chuvochina et al. 2024
  • ** "Pelagibaculales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Piscirickettsiales Chuvochina et al. 2024
  • ** "Porifericomitales" Nguyen et al. 2023
  • ** "Poriferisulfidales" Nguyen et al. 2023 ex Chuvochina et al. 2023
  • ** Pseudomonadales Orla-Jensen 1921
  • ** "Rariloculales" Nguyen et al. 2022
  • ** "Reidiellales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Steroidobacterales Chuvochina et al. 2024
  • ** "Sulfuriflexales" Pallen, Rodriguez-R & Alikhan 2022
  • ** "Taraoceanobacteraceae" Zhou et al. 2020
  • ** "Tenderiales" Chuvochina et al. 2023
  • ** "Thioalbales" Pallen, Rodriguez-R & Alikhan 2022
  • ** "Thioglobales" Pallen, Rodriguez-R & Alikhan 2022
  • ** "Thiogranales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Thiohalobacterales Sorokin & Merkel 2023
  • ** Thiohalomonadales Sorokin & Merkel 2023
  • ** "Thiohalophilales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Thiohalospirales Sorokin & Merkel 2023
  • ** Thiomicrospirales Chuvochina et al. 2024
  • ** "Thiopontiales" Pallen, Rodriguez-R & Alikhan 2022
  • ** Thiotrichales Garrity, Bell & Lilburn 2005
  • ** Woeseiales Chuvochina et al. 2024
  • ** Xanthomonadales Saddler & Bradbury 2005 non Chadefaud 1950a

List of Candidate Phyla

  • "Qinglongiota" Zhang et al. 2022
  • "Salinosulfoleibacteria" Tazi et al. 2006
  • "Teskebacteria" Dojka 1998