This is a list of taxa with Candidatus status. For taxa not covered by this list, see also: the GenBank taxonomy for "effective" names as published; the Candidatus Lists and LPSN for latinate names, some sanitized to match the Code.

Phyla

"Ca. Absconditabacteria" (previously Candidate phylum SR1) ABY1 aka OD1-ABY1, subgroup of OD1 ("Ca. Parcubacteria") Candidate phylum AC1 "Ca. Acetothermia" (previously Candidate phylum OP1) "Ca. Aerophobetes" (previously Candidate phylum CD12 or BHI80-139) "Ca. Aminicenantes" (previously Candidate phylum OP8) aquifer1 aquifer2 "Ca. Berkelbacteria" (previously Candidate phylum ACD58) BRC1 CAB-I "Ca. Calescamantes" (previously Candidate phylum EM19) Candidate phylum CPR2 Candidate phylum CPR3 Candidate phylum NC10 Candidate phylum OP2 Candidate phylum RF3 Candidate phylum SAM Candidate phylum SPAM Candidate phylum TG2 Candidate phylum VC2 Candidate phylum WS1 Candidate phylum WS2 Candidate phylum WS4 Candidate phylum WYO CKC4 "Ca. Cloacimonetes" (previously Candidate phylum WWE1) CPR1 "Ca. Dependentiae" (previously Candidate phylum TM6) EM 3 "Ca. Endomicrobia" Stingl et al. 2005 "Ca. Fermentibacteria" (Hyd24-12) "Ca. Fervidibacteria" (previously Candidate phylum OctSpa1-106) GAL08 GAL15 GN01 GN03 GN04 GN05 GN06 GN07 GN08 GN09 GN10 GN11 GN12 GN13 GN14 GN15 GOUTA4 "Ca. Gracilibacteria" (previously Candidate phylum GN02, BD1-5, or BD1-5 group) Guaymas1 "Ca. Hydrogenedentes" (previously Candidate phylum NKB19) JL-ETNP-Z39 "Ca. Katanobacteria" (previously Candidate phylum WWE3) Kazan-3B-09 KD3-62 kpj58rc KSA1 KSA2 KSB1 KSB2 KSB4 "Ca. Latescibacteria" (previously Candidate phylum WS3) LCP-89 LD1-PA38 "Ca. Marinamargulisbacteria" (previously Candidate division ZB3)NCBI: Candidate division ZB3 (class), "Cyanobacteria"/"Melainabacteria" group "Ca. Marinimicrobia" (previously Marine Group A or Candidate phylum SAR406) "Ca. Melainabacteria" "Ca. Microgenomates" (previously Candidate phylum OP11) "Ca. Modulibacteria" (previously Candidate phylum KSB3) MSBL2 MSBL3 MSBL4 MSBL5 MSBL6 NPL-UPA2 NT-B4 OC31 "Ca. Omnitrophica" (previously Candidate phylum OP3) OP4 OP6 OP7 OS-K/OS-K group "Ca. Parcubacteria" (previously Candidate phylum OD1) PAUC34f "Ca. Peregrinibacteria" (previously Candidate phylum PER)NCBI: Candidatus Peregrinibacteria (phylum)UniProt: Taxonomy - Candidatus Peregrinibacteria (PHYLUM) "Ca. Poribacteria" RsaHF231 S2R-29 "Ca. Saccharibacteria" (previously Candidate phylum TM7) SBR1093 SBYG-2791 Candidate phylum SC3 Candidate phylum SC4 Sediment-1 Sediment-2 Sediment-3 Sediment-4 SHA-109 SM2F11 TA06 "Ca. Tectomicrobia" TG3 ("Ca. Chitinivibrionia") WCHB1-60 WD272 WOR-1 WOR-3 WPS-1 WPS-2 WS5 WS6 ZB2 aka OD1-ZB2 subgroup of OD1 ("Ca. Parcubacteria") "Ca. Zixibacteria"

Classes

"Ca. Lambdaproteobacteria" Anantharaman et al. 2016 "Ca. Muproteobacteria" Anantharaman et al. 2016 "Ca. Uabimicrobiia" Lodha et al. 2021 "Ca. Zetaproteobacteria" Emerson et al. 2007

Orders "Ca. Nitrosopumilales" Könneke et al. 2005 "Ca. Uabimicrobiales" Lodha et al. 2021

Families "Ca. Midichloriaceae" Montagna et al. 2013 "Ca. Nitrosopumilaceae" Könneke et al. 2005 "Ca. Procabacteriaceae" "Ca. Rhabdochlamydiaceae" "Ca. Uabimicrobiceae" Lodha et al. 2021

Genera "Ca. Accumulibacter" Hesselmann et al. 1999 "Ca. Allobeggiatoa" Hinck et al. 2011 "Ca. Arthromitus" Snel et al. 1995 "Ca. Bacilloplasma" Kostanjšek et al. 2007 "Ca. Baumannia" Moran et al. 2003 "Ca. Blochmannia" Sauer et al. 2000 "Ca. Carsonella" Thao et al. 2000 "Ca. Chlorothrix" Klappenbach and Pierson 2004 "Ca. Competibacter" Crocetti et al. 2002 "Ca. Contubernalis" Zhilina et al. 2005 "Ca. Desulforudis" "Ca. Endomicrobium" Stingl et al. 2005 "Ca. Epixenosoma" "Ca. Giganthauma" "Ca. Glomeribacter" Bianciotto et al. 2003 "Ca. Kleidoceria" Kuechler et al. 2010 "Ca. Kuenenia" Schmid et al. 2000 "Ca. Liberibacter" "Ca. Lokiarchaeum" "Ca. Lumbricincola" Nechitaylo et al. 2009 "Ca. Magnetobacterium" Murray and Stackebrandt 1995 "Ca. Methanoregula" "Ca. Microthrix" "Ca. Nardonella" Lefèvre et al. 2004 "Ca. Nitrosoarchaeum" Blainey et al. 2011 "Ca. Nitrosopumilus" Könneke et al. 2005 "Ca. Pelagibacter" Rappe et al. 2002 "Ca. Photodesmus" Hendry and Dunlap 2011 "Ca. Phytoplasma" Firrao et al. 2004 "Ca. Portiera" Thao and Baumann 2004 "Ca. Procabacter" Horn et al. 2002 "Ca. Rhabdochlamydia" "Ca. Riegeria" Gruber-Vodicka et al. 2011 "Ca. Rohrkolberia" Kuechler et al. 2011 "Ca. Salinibacter" Antón et al. 2000 "Ca. Savagella" Thompson et al. 2012 "Ca. Scalindua" "Ca. Similichlamydia" Stride et al. 2013 "Ca. Symbiothrix" Hongoh et al. 2007 "Ca. Tremblaya" Thao et al. 2002 "Ca. Uabimicrobium" Shiratori et al. 2019 "Ca. Xiphinematobacter" Vandekerckhove et al. 2000

Species and subspecies Unless otherwise noted (♦), these entries are from LPSN. "Ca. Acaryochloris bahamiensis" López-Legentil et al. 2011 "Ca. Acidianus copahuensis" Giaveno et al. 2013 "Ca. Aciduliprofundum boonei" Schouten et al. 2008

"Ca. Accumulibacter phosphatis" Hesselmann et al. 1999 "Ca. Actinobaculum timonae" Drancourt et al. 2004 "Ca. Adiaceo aphidicola" Darby et al. 2005 "Ca. Allobeggiatoa salina" Hinck et al. 2011 "Ca. Alysiomicrobium bavaricum" Kragelund et al. 2006 "Ca. Alysiosphaera europaea" Kragelund et al. 2006 "Ca. Amoebinatus massiliae" Greub et al. 2004 "Ca. Amoebophilus asiaticus" Horn et al. 2001 "Ca. Amphibiichlamydia ranarum" Martel et al. 2013 "Ca. Anadelfobacter veles" Vannini et al. 2010 "Ca. Ancillula trichonymphae" Strassert et al. 2012 "Ca. Anammoxoglobus propionicus" Kartal et al. 2007 "Ca. Anaplasma sparouinense" Duron et al. 2022 "Ca. Aquiluna rubra" Hahn 2009 "Ca. Aquirestis calciphila" Hahn and Schauer 2007 "Ca. Arcobacter sulfidicus" Wirsen et al. 2002 "Ca. Arsenophonus arthropodicus" Dale et al. 2002 "Ca. Arsenophonus phytopathogenicus" Bressan et al. 2012 "Ca. Arsenophonus triatominarum" Hypsa and Dale 1997 "Ca. Aschnera chinzeii" Hosokawa et al. 2012 "Ca. Atelocyanobacterium thalassa(♦) "Ca. Azoamicus ciliaticola" Graf et al. 2021 "Ca. Bacteroides massiliae" Drancourt et al. 2004 "Ca. Bartonella ancashi" Blazes et al. 2013 "Ca. Bartonella antechini" Kaewmongkol et al. 2011 "Ca. Bartonella breitschwerdtii(♦) "Ca. Bartonella bandicootii" Kaewmongkol et al. 2011 "Ca. Bartonella durdenii(♦) "Ca. Bartonella eldjazairii(♦) "Ca. Bartonella mayotimonensis" Lin et al. 2010 "Ca. Bartonella melophagi(♦) "Ca. Bartonella merieuxii" Chomel et al. 2012 "Ca. Bartonella monaxi(♦) "Ca. Bartonella rudakovii(♦) "Ca. Bartonella thailandensis" Saisongkorh et al. 2009 "Ca. Bartonella volans(♦) "Ca. Bartonella woyliei" Kaewmongkol et al. 2011 "Ca. Baumannia cicadellinicola" Moran et al. 2003 "Ca. Benitsuchiphilus tojoi" Hosokawa et al. 2010 "Ca. Berkiella aquae" Mehari et al. 2016 "Ca. Berkiella cookevillensis" Mehari et al. 2016 "Ca. Blochmannia floridanus" Sauer et al. 2000 "Ca. Blochmannia herculeanus" Sauer et al. 2000 "Ca. Blochmannia rufipes" Sauer et al. 2000 "Ca. Borrelia tachyglossi" Loh et al. 2017 "Ca. Borrelia texasensis" Lin et al. 2005 "Ca. Branchiomonas cysticola" Toenshoff et al. 2012 "Ca. Brocadia anammoxidans" Jetten et al. 2001 "Ca. Brocadia caroliniensis" Magrí et al. 2012 "Ca. Brocadia fulgida" Kartal et al. 2004 "Ca. Brocadia sinica" Hu et al. 2010 "Ca. Brownia rhizoecola" Gruwell et al. 2010 "Ca. Burkholderia andongensis" Lemaire et al. 2011 "Ca. Burkholderia calva" Van Oevelen et al. 2004 "Ca. Burkholderia crenata(♦) "Ca. Burkholderia hispidae" Lemaire et al. 2012 "Ca. Burkholderia kirkii" Van Oevelen et al. 2002 "Ca. Burkholderia mamillata(♦) "Ca. Burkholderia nigropunctata" Van Oevelen et al. 2004 "Ca. Burkholderia petitii" Lemaire et al. 2011 "Ca. Burkholderia rigidae" Lemaire et al. 2012 "Ca. Burkholderia schumannianae" Lemaire et al. 2012 "Ca. Burkholderia verschuerenii(♦) "Ca. Burkholderia virens(♦) "Ca. Caedibacter acanthamoebae" Horn et al. 1999 "Ca. Caldiarchaeum subterraneum" Nunoura et al. 2011 "Ca. Campylobacter hominis" Lawson et al. 1998 "Ca. Captivus acidiprotistae" Baker et al. 2003 "Ca. Cardinium hertigii" Zchori-Fein et al. 2004 "Ca. Carsonella ruddii" Thao et al. 2000 "Ca. Chloracidobacterium thermophilum" Bryant et al. 2007 "Ca. Chlorothrix halophila" Klappenbach and Pierson 2004 "Ca. Chryseobacterium massiliae" Greub et al. 2004 "Ca. Chryseobacterium timonae" Drancourt et al. 2004 "Ca. Clavochlamydia salmonicola" Karlsen et al. 2008 "Ca. Cloacamonas acidaminovorans" Pelletier et al. 2008 "Ca. comitans" Jacobi et al. 1996 "Ca. Competibacter phosphatis" Crocetti et al. 2002 "Ca. Consessoris aphidicola" Darby et al. 2005 "Ca. Contubernalis alkalaceticum" Zhilina et al. 2005 "Ca. Cryptoprodotis polytropus" Ferrantini et al. 2009 "Ca. Curculioniphilus buchneri" Toju et al. 2009 "Ca. Cyrtobacter comes" Vannini et al. 2010 "Ca. Cyrtobacter zanobii" Boscaro et al. 2013 "Ca. Defluviella procrastinata" Boscaro et al. 2013 "Ca. Desulforudis audaxviator" Chivian et al. 2008 "Ca. Desulfovibrio trichonymphae" Sato et al. 2009 "Ca. Devosia euplotis" Vannini et al. 2004 "Ca. Ecksteinia adelgidicola" Toenshoff et al. 2012 "Ca. Ehrlichia walkerii" Brouqui et al. 2003 "Ca. Endobugula glebosa" Lim and Haygood 2004 "Ca. Endobugula sertula" Haygood and Davidson 1997 "Ca. Endolissoclinum faulkneri" Kwan et al. 2012 "Ca. Endoecteinascidia frumentensis" Pérez-Matos et al. 2007 "Ca. Endomicrobium pyrsonymphae" Stingl et al. 2005 "Ca. Endomicrobium trichonymphae" Stingl et al. 2005 "Ca. Endonucleobacter bathymodioli" Zielinski et al. 2009 "Ca. Endoriftia persephone" Robidart et al. 2008 "Ca. Endowatersipora palomitas" Anderson and Haygood 2007 "Ca. Endowatersipora rubus" Anderson and Haygood 2007 "Ca. Entotheonella palauensis" Schmidt et al. 2000 "Ca. Epiflobacter spp." Xia et al. 2008 "Ca. Erwinia dacicola" Capuzzo et al. 2005 "Ca. Evansia muelleri" Kuechler et al. 2013 "Ca. Flaviluna lacus" Hahn 2009 "Ca. Fodinabacter communificans" Bertin et al. 2011 "Ca. Francisella noatunensis subsp. endociliophora" Schrallhammer et al. 2011 "Ca. Frankia datiscae" Persson et al. 2011 "Ca. Fritschea bemisiae" Everett et al. 2005 "Ca. Fritschea eriococci" Everett et al. 2005 "Ca. Gillettellia cooleyia" Toenshoff et al. 2012 "Ca. Gilliamella apicola" Martinson et al. 2012 "Ca. Glomeribacter gigasporarum" Bianciotto et al. 2003 "Ca. Gortzia infectiva" Boscaro et al. 2012 "Ca. Haliscomenobacter calcifugiens" Hahn and Schauer 2007 "Ca. Halomonas phosphatis" Nguyen et al. 2012 "Ca. Hamiltonella defensa" Moran et al. 2005 "Ca. Helicobacter bovis" De Groote et al. 1999 "Ca. Helicobacter heilmannii" O'Rourke et al. 2004 "Ca. Helicobacter suis" De Groote et al. (includes strains previously known as Helicobacter heilmannii type one) "Ca. Heliomonas lunata" Asao et al. 2012 "Ca. Hemipteriphilus asiaticus" Bing et al. 2013 "Ca. Hemobacterium ranarum" Zhang and Rikihisa 2004 (previously known as Aegyptianella ranarum) "Ca. Hepatincola porcellionum" Wang et al. 2004 "Ca. Hepatobacter penaei" Numan et al. 2013 "Ca. Hepatoplasma crinochetorum" Wang et al. 2004 "Ca. Hodgkinia cicadicola" McCutcheon et al. 2009 "Ca. Holdemania massiliensis(♦) "Ca. Ishikawaella capsulata" Hosokawa et al. 2006 "Ca. Isobeggiatoa divolgata" Salman et al. 2011 "Ca. Jettenia asiatica" Quan et al. 2008 "Ca. Kinetoplastibacterium blastocrithidii" Du et al. 1994 "Ca. Kinetoplastibacterium crithidii" Du et al. 1994 "Ca. Kleidoceria schneideri" Kuechler et al. 2010 "Ca. Kopriimonas aquarianus" Quinn et al. 2012 "Ca. Korarchaeum cryptofilum" Elkins et al. 2008 "Ca. Koribacter versatilis" Ward et al. 2009 "Ca. Kuenenia stuttgartiensis" Schmid et al. 2000 "Ca. Lariskella arthropodarum" Matsuura et al. 2012 "Ca. Legionella jeonii" Park et al. 2004 "Ca. Liberibacter americanus" Teixeira et al. 2005 - one cause of Citrus greening disease "Ca. Liberibacter africanus" Roberts et al. 2015 - one cause of Citrus greening disease