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]

Phylum [Actinomycetota]

Phylum "[Sysuimicrobiota]"

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]

Phylum [Bacillota]

Firmicutes incertae sedis

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

Clade "Selenobacteria"

Clade "[Desulfotomaculota]"

Clade "Halanaerobiota">Halanaerobiales">Halanaerobiota"

Clade "Clostridiota"

Clade Bacillota D

Clade [Bacillota]

Clade Cyanoprokaryota

Phylum "[Margulisiibacteriota]"

Phylum "Cyanobacteriota">Cyanobacteria">Cyanobacteriota"

Kingdom [Thermotogati]

Phylum [Atribacterota]

Phylum [Synergistota]

Phylum Dictyoglomerota">Dictyoglomota">Dictyoglomerota

Phylum [Thermodesulfobiota]

Phylum [Coprothermobacterota]

Phylum "[Lithacetigenota]"

Phylum [Caldisericota]

Phylum [Thermotogota]

Phylum "[Bipolaricaulota]"

Phylum [Fusobacteriota]

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]"

Phylum "[Babelota]"

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

Phylum [Campylobacterota]

Phylum [Spirochaetota]

Phylum "[Goldiibacteriota]"

  • "Candidatus Cellulosimonas" Doud et al. 2020

Phylum "[Ryujiniota]"

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

Phylum [Elusimicrobiota]

Phylum "[Aerophobota]"

Phylum "[Omnitrophota]"

Phylum "[Fidelibacterota]"

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]"

Phylum "[Hinthialibacterota]"

Phylum "[Sumerlaeota]"

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

Phylum "[Poribacteriota]"

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]

Phylum [Verrucomicrobiota]

Clade [FCB group]

Phylum "[Tangaroaeota]"

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

Phylum "[Latescibacterota]"

Phylum "[Fermentibacterota]"

Phylum "[Orphanbacterota]"

Phylum "[Arandabacterota]"

Phylum "[Joyebacterota]"

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

Phylum "[Krumholzibacteriota]"

Phylum "[Blakebacterota]"

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

Phylum [Gemmatimonadota]

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]

Phylum "[Marinisomatota]"

Phylum [Calditrichota]

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

Phylum "[Zhuqueibacterota]"

Phylum "[Effluvivivacota]"

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

Phylum [Bacteroidota]_A

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

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]"

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]

Phylum "[Nitrosediminicolota]"

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]"

Phylum [Nitrospinota]

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

Phylum "[Methylomirabilota]"

Phylum [Nitrospirota]

Phylum [Thermodesulfobacteriota]

Phylum "[Leptospirillaeota]"

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

Phylum "[Desulfovibrionota]"

Phylum SAR324

Phylum "[Oligoflexaeota]"

Phylum [Chrysiogenota]

Phylum [Pseudomonadota]

List of Candidate Phyla