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1
Valid publication of names of two domains and seven kingdoms
ofprokaryotes
MarkusGöker1,* and AharonOren2
RESEARCH ARTICLE
Göker and Oren, Int. J. Syst. Evol. Microbiol. 2024;74:006242
DOI 10.1099/ijsem.0.006242
Author aliations: 1Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Inhoenstrasse 7B, D- 38124 Braunschweig,
Germany; 2The Hebrew University of Jerusalem, The Institute of Life Sciences, Edmond J. Safra Campus - Givat Ram, 9190401 Jerusalem, Israel.
*Correspondence: Markus Göker, markus. goeker@ dsmz. de
Keywords: domain; International Code of Nomenclature of Prokaryotes; kingdom; valid publication.
Abbreviations: ICNP, International Code of Nomenclature of Prokaryotes; ICSP, International Committee on Systematics of Prokaryotes.
006242 © 2024 The Authors
This is an open- access article distributed under the terms of the Creative Commons Attribution License. This article was made open access via a Publish and Read agreement between
the Microbiology Society and the corresponding author’s institution.
Abstract
The International Code of Nomenclature of Prokaryotes (ICNP) now includes the categories domain and kingdom. For the purpose
of the valid publication of their names under the ICNP, we consider here the two known domains, ‘Bacteria’ and ‘Archaea’, as well
as a number of taxa suitable for the rank of kingdom, based on previous phylogenetic and taxonomic studies. It is proposed to
subdivide the domain Bacteria into the kingdoms Bacillati, Fusobacteriati, Pseudomonadati and Thermotogati. This arrangement
reflects contemporary phylogenetic hypotheses as well as previous taxonomic proposals based on cell wall structure, includ-
ing ‘diderms’ vs. ‘monoderms’, Gracilicutes vs. Firmicutes, ‘Negibacteria’ vs. ‘Unibacteria’, ‘Hydrobacteria’ vs. ‘Terrabacteria’, and
‘Hydrobacterida’ vs. ‘Terrabacterida’. The domain Archaea is proposed to include the kingdoms Methanobacteriati, Nanobdellati
and Thermoproteati, reflecting the previous division into ‘Euryarchaeota’, ‘DPANN superphylum’ and ‘TACK superphylum’.
INTRODUCTION
e 2022 revision of the International Code of Nomenclature of Prokaryotes, or ICNP [1], lists the phylum category together
with the other categories accepted in prokaryotic nomenclature, based on recent emendations [2]. e inclusion of this category
led to the valid publication of 42 phylum names [3, 4], which was followed by the valid publication of Cyanobacteriota in 2022
[5, 6] and of four additional phylum names in 2023 [7]. e phylum name Microcaldota was recently proposed [8] and is included
in Validation List No. 214 [9]. Of the ve phylum names proposed by Chuvochina et al. [10], three names, Halobacteriota,
ermoplasmatota and ermosuldibacterota, will be validly published [11] by inclusion in Validation List No. 215 [12].
Recently, the International Committee on Systematics of Prokaryotes (ICSP) voted on a proposal to add two categories above the
phylum rank, kingdom and domain, to the ICNP [13]. is proposal to emend the ICNP was adopted by a large majority [14].
e purpose of this study is to propose names for domains and kingdoms (Table1). We briey describe the nomenclatural rationale
for the two taxonomically well- established domain names [13] and propose them for valid publication. Similarly, appropriate
taxonomic concepts from the literature that t the kingdom rank [13] are considered to propose names for valid publication
according to the new rules of the ICNP. Where appropriate, the proposed names are attributed to the authors of the original
taxonomic concepts [3, 4, 7, 15]. e proper citation of these names would have to be in accordance with Rule 33b, Chapter 4(B)
(1) and Chapter 4(B)(2) of the ICNP [1].
VALID PUBLICATION OF THE DOMAIN NAMES BACTERIA AND ARCHAEA
In order to stabilize the nomenclature of domain names, we propose to keep the well- known names ‘Bacteria’ and ‘Archaea’
(Table1), introduced by Woese et al. in 1990 [16]. According to the recently adopted emendation of Rule 8 of the ICNP, the name
of a domain (dominion, dominium) is in the plural number and written with an initial capital letter. e only component of the
name is the nominative plural of a word that is the last component of the name of a genus, whether it is the type genus of the
domain or any other genus placed within the domain at the time of valid publication of its name [14]. According to the emended
Rule 22, the nomenclatural type of a domain is one of the contained genera. e nomenclatural type shall be designated by the
OPEN
ACCESS
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author at the time of the proposal of the domain name. When doing so, authors are encouraged to consider which genus name
was validly published rst or, particularly in the case of names from the Approved Lists of Bacterial Names [17], which name
was eectively published rst.
e rst genera with a validly published that are also type genera of bacterial phyla with a validly published name [3, 4] are
Spirochaeta Ehrenberg 1835 (Approved Lists 1980) [17, 18], Bacillus Cohn 1872 (Approved Lists 1980) [17, 19], Actinomyces
Harz 1877 (Approved Lists 1980) [17, 20], Myxococcus axter 1892 (Approved Lists 1980) [17, 21] and Pseudomonas Migula
1894 (Approved Lists 1980) [17, 22]. Among these, Spirochaeta, Actinomyces and Myxococcus have unusual morphologies or life
cycles for bacteria. For this reason, Bacillus is the preferred choice for the type genus of Bacteria. Note that Rule 22 of the ICNP
does not stipulate that the genus with the rst validly published name placed in a taxon above genus rank has to be chosen as
type genus. Rule 22 only provides a recommendation in this regard [1, 14].
e oldest type genus of an archaeal phylum with a validly published name among the 42 phyla rst proposed under the ICNP
[3, 4] is ermoproteus Zillig and Stetter 1982 [23, 24]. More recently, however, Methanobacteriota has been validly published [7],
making Methanobacterium Kluyver and van Niel 1936 (Approved Lists 1980) [17, 25] the genus with the rst validly published
name that is also the type genus of an archaeal phylum. Methanobacterium is well suitable as the type genus for Archaea.
Taxonomic proposals
Bacteria Woese, Kandler and Wheelis dom. nov.
Bac. te’ri.a. N.L. neut. n. bacterium, denoting a rod, sta or stick, and thus the last component in many names of genera currently
placed in this domain; N.L. neut. pl. n. Bacteria, the domain of the bacteria.
e description of the domain is as given by Woese et al. [16] with the following addition. At the time of writing, the domain
contains the phyla with a validly published name Abditibacteriota, Acidobacteriota, Actinomycetota, Aquicota, Armatimonadota,
Atribacterota, Bacillota, Bacteroidota, Balneolota, Bdellovibrionota, Caldisericota, Calditrichota, Campylobacterota, Chlamydiota,
Chlorobiota, Chloroexota, Chrysiogenota, Coprothermobacterota, Cyanobacteriota, Deferribacterota, Deinococcota, Desulfobac-
terota, Dictyoglomerota, Elusimicrobiota, Fibrobacterota, Fusobacteriota, Gemmatimonadota, Ignavibacteriota, Kiritimatiellota,
Lentisphaerota, Mycoplasmatota, Myxococcota, Nitrospinota, Nitrospirota, Planctomycetota, Pseudomonadota, Rhodothermota,
Spirochaetota, Synergistota, ermodesulfobacteriota, ermodesulfobiota, ermomicrobiota, ermosuldibacterota, ermo-
togota and Verrucomicrobiota (some of which may be considered synonyms). e properties of the domain are those of the
included phyla. e domain includes a large number of genera with validly published names ending in - bacterium, such as, e.g.,
Fusobacterium Knorr 1922 (Approved Lists 1980) [17, 26]. e type genus is Bacillus Cohn 1872 (Approved Lists 1980) [17, 19].
Archaea Woese, Kandler and Wheelis dom. nov.
Ar. chae’a. Gr. masc. adj. archaios, ancient; N.L. neut. n. archaeum, denoting an archaeon, and therefore the last component in
some of the names of genera currently placed in this domain; N.L. neut. pl. n. Archaea, the domain of the archaea.
e description of the domain is as given by Woese et al. [16] with the following addition. At the time of writing, the domain
contains the phyla with a validly published name Methanobacteriota, Nanobdellota, Nitrososphaerota and ermoproteota; addi-
tional phylum names validly published in the near future are Halobacteriota, Microcaldota and ermoplasmatota (some of which
may be considered synonyms). e properties of the domain are those of the included phyla. e domain includes some genera
Table 1. Overview of the proposed high- level classification of prokaryotes, including previously known names for the kingdoms
Domain Kingdom
Bacteria
Bacillati (divisions Firmicutes and ‘Tenericutes’, ‘Terrabacteria’, ‘Terrabacterida’, monoderms pro parte, subkingdom ‘Unibacteria’ pro parte)
Fusobacteriati (‘Fusobacterida’)
Pseudomonadati (division Gracilicutes, ‘Hydrobacteria’, ‘Hydrobacterida’ and ‘Aquicida’, diderms, subkingdom ‘Negibacteria’)
ermotogati (‘ermotogida’)
Archaea
Methanobacteriati (phylum ‘Euryarchaeota’ sensu lato, ‘Euryarchaeida’)
Nanobdellati (DPANN superphylum)
ermoproteati (TACK superphylum, ‘Crenarchaeida’)
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Göker and Oren, Int. J. Syst. Evol. Microbiol. 2024;74:006242
with validly published names ending in - archaeum, such as, e.g., Halarchaeum Minegishi et al. 2010 [27, 28]. e type genus is
Methanobacterium Kluyver and van Niel 1936 (Approved Lists 1980) [17, 25].
VALID PUBLICATION OF NAMES OF KINGDOMS OF BACTERIA
According to the recently adopted emendation of Rule 8 of the ICNP, the name of a kingdom (regnum) is in the masculine gender,
the plural number, and written with an initial capital letter. e name is formed by adding the sux - ati to the stem of the name
of the designated type genus [14]. e names of taxa proposed in the literature at the rank of kingdom or similar ranks do not
conform to a uniform naming scheme and are not suitable for deriving such a scheme [13]. It is therefore necessary to propose
other names that can be validly published.
e higher classication of Bacteria is hampered by the relatively low phylogenetic resolution at the backbone of phylogenetic
trees, even when based on sampling many genes or on a set of genes specically selected for this purpose [29–39]. is makes it
necessary to take phylogenetic uncertainty into account when selecting the type genus of a kingdom, although the recommenda-
tions of the ICNP in Rule 22 for choosing a type genus are the same as for domains [14].
An overview of the names of prokaryotic taxa above phylum rank has been given previously [13]. Attempts to subdivide prokary-
otes on the basis of their cell wall structure were made even before the split into Bacteria and Archaea was recognized (Table1).
Gibbons and Murray [40] proposed the dissection of the kingdom ‘Procaryotae’ into three divisions: the Gram- negative Gracili-
cutes, the Gram- positive Firmacutes, and the ‘Mollicutes’, which lack a cell wall. Murray [41] kept Gracilicutes, orthographically
corrected Firmacutes to Firmicutes corrig., used the division ‘Tenericutes’ instead of ‘Mollicutes’, which was reduced in rank to a
class, and added the division ‘Mendosicutes’ to accommodate the class ‘Archaebacteria’. Taking phylogenetic results into account,
Gupta [42–44] distinguished between diderms (Gram- negative bacteria) and monoderms (Gram- positive bacteria and ‘Archae-
bacteria’). Cavalier- Smith [45] dierentiated between the subkingdoms ‘Negibacteria’ and ‘Unibacteria’ within ‘Bacteria’, which
he considered to be the sole kingdom within the empire or superkingdom ‘Prokaryota’. ‘ Unibacteria’ included the infrakingdoms
‘Posibacteria’ and ‘Archaebacteria’. ese were later considered by the same author to be phyla within ‘Unibacteria’ [46].
Battistuzzi et al. [29] included the phyla now known as Actinomycetota, Cyanobacteriota and Deinococcota in a group called
‘Terrabacteria’ in order to reect postulated ancient adaptations to life on land. Battistuzzi and Hedges [30] expanded this
group to include Actinomycetota, Bacillota, Cyanobacteriota, Chloroexota, Deinococcota and Mycoplasmatota. eir analysis
also showed an early branching and an isolated position, respectively, of the phyla know known as Aquicota, Fusobacteriota and
ermotogota. All other bacterial phyla considered in the study were included in a group called ‘Hydrobacteria’ [30]; the validly
published names of these phyla are now Bacteroidota, Chlamydiota, Chlorobiota, Desulfobacterota, Myxococcota, Planctomycetota,
Pseudomonadota and Spirochaetota [3–7]. is makes ‘Hydrobacteria’ and ‘Terrabacteria’ largely, but not entirely [47], equivalent
to Gracilicutes Gibbons and Murray 1978 (Approved Lists 1980) and Firmicutes corrig. Gibbons and Murray 1978 (Approved
Lists 1980), respectively [17, 40].
While the name ‘Hydrobacteria’ was rarely used in the later literature, several studies phylogenetically recovered the group called
‘Terrabacteria’. A notable exception is the study by Cavalier- Smith and Chao [36], which emphasized the non- monophyly of ‘Ter ra-
bacteria’. Rinke et al. [31], Sekiguchi et al. [32], Parks et al. [35] and Yabe et al. [38] included Actinomycetota, Armatimonadota,
Bacillota, Cyanobacteriota, Chloroexota, Deinococcota and Mycoplasmatota in ‘Terrabacteria’. e analysis of Kirkegaard and
coworkers [33] concurred except for the slightly dierent phylogenetic position of Mycoplasmatota. Ji et al. [34] also almost agreed
on ‘Terrabacteria’ but showed Cyanobacteriota in a distinct position. Luketa [48] fully agreed with the results of Battistuzzi and
Hedges [30] and accordingly proposed the ve bacterial kingdoms ‘Aquicida’, ‘ Fusobacterida’, ‘ Hydrobacterida’, ‘Terrabacterida’
and ‘ermotogida’.
Intriguingly, recent phylogenomic studies [37, 39, 49–52] juxtapose the groups ‘Terrabacteria’ and Gracilicutes, the latter being
very similar to ‘Hydrobacteria’. Moreover, these studies indicate an isolated position of some of the bacterial phyla not included
in either ‘Terrabacteria’ or ‘Hydrobacteria’ by Battistuzzi and Hedges [30]. e study by Coleman et al. [37] diers from the
much earlier analysis by including Aquicota in Gracilicutes and by including Deinococcota not in ‘Terrabacteria’ but in a clade
also comprising Synergistota and ermotogota. e topologies presented in other studies examining the diderm–monoderm
transition diered in part [53, 54], but this may be due to the use of fewer genes and dierent rooting approaches. us, despite
the partially low phylogenetic resolution, the taxonomically preferable solution for bacterial kingdoms seems to be to accept the
subdivision apparent in the study by Battistuzzi and Hedges [30], but to rene it according to more recent results [37, 52]. is
reasoning suggests the proposal of Bacillati, Fusobacteriati, Pseudomonadati and ermotogati.
Taxonomic proposals
Bacillati (Gibbons and Murray) Oren and Göker regn. nov.
Ba. cil. la’ti. L. masc. n. Bacillus, type genus of the kingdom; - ati, ending to denote a kingdom; N.L. masc. pl. n. Bacillati, the
Bacillus kingdom.
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is name is an elevation in rank of the division Firmicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980) [17, 40]. e
description is as given for this division with the following additions. e kingdom contains the phyla with a validly published
name Actinomycetota, Armatimonadota, Bacillota, Cyanobacteriota, Chloroexota and Mycoplasmatota [3–6], some of which may
be considered synonyms. e properties of the kingdom are those of the included phyla. e relatively close phylogenetic position
of all, or at least most, of these phyla has been demonstrated in several studies [30–35, 37–39]; the group has been proposed as
‘Terrabacteria’ by Battistuzzi et al. [29] and as kingdom ‘Terrabacterida’ by Luketa [48]; it also largely corresponds to the division
Firmicutes corrig. Gibbons and Murray (Approved Lists 1980) [17, 40]. Based on the study by Coleman et al. [37], Deinococcota
is not included in the kingdom. e type genus of the kingdom is Bacillus Cohn 1872 (Approved Lists 1980) [17, 19].
Fusobacteriati Battistuzzi and Hedges regn. nov.
Fu. so. bac. te. ri.a’ti. N.L. neut. n. Fusobacterium, type genus of the kingdom; - ati, ending to denote a kingdom; N.L. masc. pl. n.
Fusobacteriati, the Fusobacterium kingdom.
is name is based on the concept of ‘Fusobacteria’ (as a taxon of the same rank as ‘Hydrobacteria’ and ‘Terrabacteria’) by
Battistuzzi and Hedges [30] with the following additions. e kingdom contains the phylum with a validly published name
Fusobacteriota [3, 4]. e properties of the kingdom are those of the included phylum. e relatively isolated phylogenetic position
of the phylum has been demonstrated in several studies [30, 37, 39]; the group has been proposed by Luketa [48] as the kingdom
‘Fusobacterida’. e type genus of the kingdom is Fusobacterium Knorr 1922 (Approved Lists 1980) [17, 26].
Pseudomonadati (Gibbons and Murray) Oren and Göker regn. nov
Pseu. do. mo. na. da’ti. N.L. fem. n. Pseudomonas, type genus of the kingdom; - ati, ending to denote a kingdom; N.L. masc. pl. n.
Pseudomonadati, the Pseudomonas kingdom.
is name is an elevation in rank of the division Gracilicutes corrig. Gibbons and Murray 1978 (Approved Lists 1980) [17, 40]. e
description is as given for this division with the following additions. e kingdom contains the phyla with a validly published name
Abditibacteriota, Acidobacteriota, Aquicota, Atribacterota, Bacteroidota, Balneolota, Bdellovibrionota, Caldisericota, Calditri-
chota, Campylobacterota, Chlamydiota, Chlorobiota, Chrysiogenota, Coprothermobacterota, Deferribacterota, Desulfobacterota,
Dictyoglomerota, Elusimicrobiota, Fibrobacterota, Gemmatimonadota, Ignavibacteriota, Kiritimatiellota, Lentisphaerota, Myxo-
coccota, Nitrospinota, Nitrospirota, Planctomycetota, Pseudomonadota, Rhodothermota, Spirochaetota, ermodesulfobacteriota,
ermodesulfobiota, ermomicrobiota, ermosuldibacterota and Verrucomicrobiota [3, 4, 7], some of which may be considered
synonyms. e properties of the kingdom are those of the included phyla. e relatively close phylogenetic position of all, or at
least most, of these phyla has been demonstrated in several studies [30, 37, 39]. e group has been proposed as ‘Hydrobacteria’
by Battistuzzi and Hedges [30] and as the kingdom ‘Hydrobacterida’ by Luketa [48]; the group is also largely equivalent to the
division Gracilicutes Gibbons and Murray [17, 40]. Based on the study by Coleman et al. [37], Aquicota is tentatively placed in
the kingdom. e type genus of the kingdom is Pseudomonas Migula 1894 (Approved Lists 1980) [17, 22].
Thermotogati Battistuzzi and Hedges regn. nov.
er. mo. to. ga’ti. N.L. fem. n. ermotoga, type genus of the kingdom; - ati, ending to denote a kingdom; N.L. masc. pl. n. er-
motogati, the ermotoga kingdom.
is name is based on the concept of ‘ermotogae’ (as a taxon of the same rank as ‘Hydrobacteria’ and ‘Terrabacteria’) by Battis-
tuzzi and Hedges [30] with the following additions. e kingdom contains the phyla with a validly published name Deinococcota,
Synergistota, and ermotogota [3, 4]. e properties of the kingdom are those of the included phyla. e relatively isolated
phylogenetic position of ermotogota has been demonstrated in several studies [30, 39]. e group has been proposed as the
kingdom ‘ermotogida’ by Luketa [48]. Deinococcota and Synergistota are tentatively placed in this kingdom based on the study
of Coleman et al. [37]. e type genus of the kingdom is ermotoga Stetter and Huber 1986 [55, 56].
VALID PUBLICATION OF NAMES OF KINGDOMS OF ARCHAEA
e naming of archaeal kingdoms now implemented in the ICNP does not dier from that proposed for Bacteria [14]. Based
on the published phylogenetic hypotheses for Archaea [35, 57–70], we propose the establishment of three kingdoms, the Metha-
nobacteriati, the Nanobdellati, and the ermoproteati. Not all of these three groups appear to be monophyletic in all published
phylogenetic analyses [36, 39, 71–79], but they do so in most of them, which is why they have three well known but not validly
published names [13].
e Methanobacteriati include the organisms formerly classied as ‘Euryarchaeota’ by Garrity and Holt [80]: the phylum Metha-
nobacteriota Garrity and Holt 2023 [7], originally considered coextensive with ‘Euryarchaeota’, and the phyla Halobacteriota
Chuvochina et al. 2024 [10, 12] and ermoplasmatota Chuvochina et al. 2024 [10, 12], which were created by splitting ‘Euryar-
chaeota’ Garrity and Holt 2001 sensu lato [80]. Luketa proposed the name ‘Euryarchaeida’ for ‘Euryarchaeota’ sensu lato [48],
based on the work of Elkins et al. [81].
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e Nanobdellati include the organisms previously classied in the ‘DPANN superphylum’ (‘Diapherotrites’, ‘ Parvarchaeota’,
‘Aenigmarchaeota’, ‘ Nanoarchaeota’ and ‘Nanohalarchaeota’) [31]. e validly published phylum name Nanobdellota Huber et
al. 2023 [7] was proposed for ‘Nanoarchaeota’ [82, 82], while Microcaldota Sakai et al. 2023 [8, 9] was proposed for Candidatus
Micrarchaeota Baker and Dick 2013 [83, 84]. Candidatus Micrarchaeota is also placed within the ‘DPANN superphylum’ [83].
‘Diapherotrites’, ‘ Parvarchaeota’, ‘Aenigmarchaeota’ and ‘Nanohaloarchaeota’, which originate from a publication by Rinke et
al. [31], should be understood as Candidatus phyla: Candidatus Iainarchaeota corrig., Candidatus Parvarchaeota, Candidatus
Aenigmatarchaeota corrig., and Candidatus Nanohalarchaeota, respectively [84].
e ermoproteati include the organisms previously classied in the ‘TACK superphylum’ (‘aumarchaeota’, ‘ Aigarchaeota’,
‘Crenarchaeota’, and ‘Korarchaeota’) [57]. Luketa proposed the name ‘Crenarchaeida’ for this group [48], based on the work
of Elkins et al. [81]. e validly published phylum name Nitrososphaerota Brochier- Armanet et al. 2021 [3, 4] was proposed
for ‘aumarchaeota’ Brochier- Armanet et al. 2008 [85], while ermoproteota Garrity and Holt 2021 [3, 4] was proposed for
‘Crenarchaeota’ Garrity and Holt 2001 [86]. ‘Aigarchaeota’ Nunoura et al. 2011 [87] should be read as Candidatus Augarchaeota
corrig. [84]. ‘Korarchaeota’ Ludwig and Klenk 2001 [88] should also be interpreted as Candidatus phylum [84].
Taxonomic proposals
Methanobacteriati (Garrity and Holt) Oren and Göker regn. nov.
Me. tha. no. bac. te. ri.a’ti. N.L. neut. n. Methanobacterium, type genus of the kingdom; - ati, ending to denote a kingdom; N.L. masc.
pl. n. Methanobacteriati, the Methanobacterium kingdom.
is name is an elevation in rank of the phylum Methanobacteriota Garrity and Holt 2023 [7]. e description is as given for this
phylum with the following additions. e kingdom contains the phyla with an already validly published or soon- to- be- validly-
published name Methanobacteriota, Halobacteriota and ermoplasmatota (some of which may be considered synonyms). e
properties of the kingdom are those of the phylum ‘Euryarchaeota’ Garrity and Holt 2001 [80] (=Methanobacteriota Garrity and
Holt 2023 sensu lato [7]=‘Euryarchaeida’ Luketa 2012 [48]). e type genus is Methanobacterium Kluyver and van Niel 1936
(Approved Lists 1980) [17, 25].
Nanobdellati Rinke, Schwientek, Sczyrba, Ivanova, Anderson, Cheng, Darling, Malfatti, Swan, Gies, Dodsworth, Hedlund,
Tsiamis, Sievert, Liu, Eisen, Hallam, Kyrpides, Stepanauskas, Rubin, Hugenholtz and Woyke regn. nov.
Na. no. bdel. la’ti. N.L. fem. n. Nanobdella, type genus of the kingdom; - ati, ending to denote a kingdom; N.L. masc. pl. n. Nanobdel-
lati, the Nanobdella kingdom.
is name is based on the concept of ‘DPANN superphylum’ by Rinke et al. [31] with the following additions. e kingdom
contains the phyla with a validly published name Nanobdellota and Microcaldota. Among the Candidatus phyla, the kingdom
contains at least Candidatus Aenigmatarchaeota corrig., Candidatus Iainarchaeota corrig., Candidatus Nanohalarchaeota and
Candidatus Parvarchaeota. e properties are those reported for the ‘DPANN superphylum’ [31]. e type genus is Nanobdella
Kato et al. 2022 [4, 89].
Thermoproteati Guy and Ettema regn. nov.
er. mo. pro. te.a’ti. N.L. masc. n. ermoproteus, type genus of the kingdom; - ati, ending to denote a kingdom; N.L. masc. pl. n.
ermoproteati, the ermoproteus kingdom.
is name is based on the concept of the ‘TACK superphylum’, summarized by Guy and Ettema [57], with the following additions.
e kingdom contains the phyla with a validly published name Nitrososphaerota and ermoproteota. Among the Candidatus
phyla, the kingdom contains at least Candidatus Augarchaeota corrig. [84, 87] and Candidatus Korarchaeota [84, 88]. e proper-
ties are those reported for the ‘TACK superphylum’ [57] (=‘Crenarchaeida’ Luketa 2012 [48]). e type genus is ermoproteus
Zillig and Stetter 1982 [23, 24].
Funding information
The authors received no specific grant from any funding agency.
Conflicts of interest
The authors declare that there are no conflicts of interest.
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