Nanobdellati ( syn. "DPANN") is a kingdom of

archaea Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even thou ...

first proposed in 2013. Many members show novel signs of

horizontal gene transfer Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). HGT is an important factor in the e ...

from other domains of

life Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, met ...

. They are known as nanoarchaea or ultra-small archaea due to their smaller size (nanometric) compared to other archaea. "DPANN" is an acronym formed by the initials of the first five groups discovered:

Diapherotrites Nanobdellati (Synonym (taxonomy), syn. "DPANN") is a Kingdom (biology), kingdom of archaea first proposed in 2013. Many members show novel signs of horizontal gene transfer from other domains of life. They are known as nanoarchaea or ultra-small ...

Parvarchaeota Parvarchaeota is a phylum of archaea belonging to the Nanobdellati kingdom. They have been discovered in acid mine drainage waters and later in marine sediments. The cells of these organisms are extremely small consistent with small genomes. ...

Aenigmarchaeota Nanobdellati ( syn. "DPANN") is a kingdom of archaea first proposed in 2013. Many members show novel signs of horizontal gene transfer from other domains of life. They are known as nanoarchaea or ultra-small archaea due to their smaller size (na ...

, Nanoarchaeota and

Nanohaloarchaeota Nanohaloarchaea is a clade of diminutive archaea with small genomes and limited metabolic capabilities, belonging to kingdom Nanobdellati. They are ubiquitous in hypersaline habitats, which they share with the extremely halophilic haloarchaea. ...

. Later

Woesearchaeota Nanobdellati ( syn. "DPANN") is a kingdom of archaea first proposed in 2013. Many members show novel signs of horizontal gene transfer from other domains of life. They are known as nanoarchaea or ultra-small archaea due to their smaller size (na ...

and

Pacearchaeota Nanobdellati ( syn. "DPANN") is a kingdom of archaea first proposed in 2013. Many members show novel signs of horizontal gene transfer from other domains of life. They are known as nanoarchaea or ultra-small archaea due to their smaller size (na ...

were discovered and proposed within the "DPANN"

superphylum In biology, a phylum (; : phyla) is a level of classification, or taxonomic rank, that is below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclat ...

. In 2017, another

phylum In biology, a phylum (; : phyla) is a level of classification, or taxonomic rank, that is below Kingdom (biology), kingdom and above Class (biology), class. Traditionally, in botany the term division (taxonomy), division has been used instead ...

Altiarchaeota was placed into the "DPANN" superphylum. The

monophyly In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent comm ...

of Nanobdellati is not yet considered established, due to the high

mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, ...

rate of the included phyla, which can lead to the artifact of the

long branch attraction In phylogenetics, long branch attraction (LBA) is a form of systematic error whereby distantly related lineages are incorrectly inferred to be closely related. LBA arises when the amount of molecular or morphological change accumulated within a lin ...

(LBA) where the lineages are grouped basally or artificially at the base of the

phylogenetic tree A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In ...

without being related. These analyses instead suggest that Nanobdellati belongs to

Euryarchaeota Methanobacteriota is a phylum in the domain Archaea. Taxonomy The phylum ''Methanobacteriota'' was introduced to prokaryotic nomenclature in 2023. It contains following classes: *Archaeoglobi Garrity & Holt (2002) *Halobacteria Grant ''et al ...

or is

polyphyletic A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

occupying various positions within Euryarchaeota. The Nanobdellati groups together different phyla with a variety of environmental distribution and metabolism, ranging from symbiotic and

thermophilic A thermophile is a type of extremophile that thrives at relatively high temperatures, between . Many thermophiles are archaea, though some of them are bacteria and fungi. Thermophilic eubacteria are suggested to have been among the earliest bact ...

forms such as Nanoarchaeota, acidophiles like

and non-extremophiles like

and

. Nanobdellati was also detected in

nitrate Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...

-rich

groundwater Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...

, on the water surface but not below, indicating that these taxa are still quite difficult to locate. Since the recognition of the kingdom rank by the

ICNP The International Code of Nomenclature of Prokaryotes (ICNP) or Prokaryotic Code, formerly the International Code of Nomenclature of Bacteria (ICNB) or Bacteriological Code (BC), governs the scientific names for Bacteria and Archaea.P. H. A. Sneath ...

, the only

validly published name In botanical nomenclature, a validly published name is a name that meets the requirements in the ''International Code of Nomenclature for algae, fungi, and plants'' (''ICN'') for valid publication. Valid publication of a name represents the minim ...

for this group is kingdom Nanobdellati.

Characteristics

They are characterized by being small in size compared to other

(nanometric size) and in keeping with their small

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

, they have limited but sufficient catabolic capacities to lead a free life, although many are thought to be episymbionts that depend on a

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

or parasitic association with other organisms. Many of their characteristics are similar or analogous to those of ultra-small bacteria (CPR group). Limited metabolic capacities are a product of the small genome and are reflected in the fact that many lack central

biosynthetic Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme- catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve ...

pathways for

nucleotides Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both o ...

, aminoacids, and

lipids Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins Vitamin A, A, Vitamin D, D, Vitamin E, E and Vitamin K, K), monoglycerides, diglycerides, phospholipids, and others. The fu ...

; hence most Nanobdellati archaea, such as ARMAN archaea, which rely on other

microbes A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

to meet their biological requirements. But those that have the potential to live freely are fermentative and

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cellu ...

heterotrophs A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

. They are mostly

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: *Adhesive#Anaerobic, Anaerobic ad ...

and have not been cultivated. They live in extreme environments such as thermophilic, hyperacidophilic, hyperhalophilic or metal-resistant; or also in the temperate environment of marine and lake

sediments Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

. They are rarely found on the ground or in the open ocean.

Classification

. Found by phylogenetic analysis of the genomes recovered from the groundwater filtration of a

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

mine abandoned in the

USA The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

. *

and

Micrarchaeota Nanobdellati (Synonym (taxonomy), syn. "DPANN") is a Kingdom (biology), kingdom of archaea first proposed in 2013. Many members show novel signs of horizontal gene transfer from other domains of life. They are known as nanoarchaea or ultra-small ...

. Discovered in 2006 in acidic mine drainage from a US mine. They are of very small size and provisionally called

ARMAN Arman (November 17, 1928 – October 22, 2005) was a French and American artist. Born Armand Fernandez in Nice, France, Arman was a painter who moved from using objects for the ink or paint traces they leave (''cachets'', ''allures d'objet'') t ...

(Archaeal Richmond Mine acidophilic nanoorganisms). *

and

. They have been identified both in sediments and in surface waters of

aquifers An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...

and

lakes A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...

, abounding especially in saline conditions. *

. Found in

wastewater Wastewater (or waste water) is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of do ...

from mines and in sediments from hot springs. * Nanohalarchaeota. Distributed in environments with high salinity. * Nanoarchaeota. They were the first discovered (in 2002) in a hydrothermal source next to the coast of

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

. They live as symbionts of other archaea.

Phylogeny

Taxonomy

The currently accepted taxonomy is based on the

List of Prokaryotic names with Standing in Nomenclature List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclatu ...

(LPSN) and

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is lo ...

(NCBI). Kingdom Nanobdellati Rinke et al. 2013 * Phylum

Microcaldota ''Microcaldus'' is a monotypic genus of ultra-small archaea. It contains one species, ''Microcaldus variisymbioticus''. It is in the monotypic family Microcaldaceae, monotypic order Microcaldales, monotypic class Microcaldia and monotypic phylum ...

Sakai et al. 2023 ** Class Microcaldia Sakai et al. 2023 *** Order ?Microcaldales Sakai et al. 2023 * Phylum " Undinarchaeota" Dombrowski et al. 2020 ** Class "Undinarchaeia" Dombrowski et al. 2020 *** Order "Undinarchaeales" Dombrowski et al. 2020 * Phylum " Huberarchaeota" Probst et al. 2019 ** Class "Huberarchaeia" corrig. Probst et al. 2019 *** Order "Huberarchaeales" Rinke et al. 2020 * Phylum " Aenigmatarchaeota" corrig. Rinke et al. 2013 (DSEG, DUSEL2) ** Class "Aenigmatarchaeia" corrig. Rinke et al. 2020 *** Order "Aenigmatarchaeales" corrig. Rinke et al. 2020 * Phylum " Nanohalarchaeota" corrig. Rinke et al. 2013 ** Class "Nanohalobiia" corrig.La Cono et al. 2020 *** Order "Nanohalobiales" La Cono et al. 2020 ** Class " Nanohalarchaeia" corrig. Narasingarao et al. 2012 *** Order ?"Nanohalarchaeales" *** Order ?"Nanohydrothermales" Xie et al. 2022 *** Order ?"Nucleotidisoterales" Xie et al. 2022 * Phylum Altarchaeota Probst et al. 2018 (SM1) ** Class "Altarchaeia" corrig. Probst et al. 2014 *** Order "Altarchaeales" corrig. Probst et al. 2014 * Phylum "Iainarchaeota" corrig. Rinke et al. 2013 ["

" Rinke et al. 2013] (DUSEL-3) ** Class "Iainarchaeia" Rinke et al. 2020 *** Order "Forterreales" Probst & Banfield 2017 *** Order "Iainarchaeales" Rinke et al. 2020 * Phylum "

" Baker & Dick 2013 ** Class "Micrarchaeia" Vazquez-Campos et al. 2021 *** Order "Anstonellales" Vazquez-Campos et al. 2021 (LFWA-IIIc) *** Order "Burarchaeales" Vazquez-Campos et al. 2021 (LFWA-IIIb) *** Order "Fermentimicrarchaeales" Kadnikov et al. 2020 *** Order "Gugararchaeales" Vazquez-Campos et al. 2021 (LFWA-IIIa) *** Order "Micrarchaeales" Vazquez-Campos et al. 2021 *** Order "Norongarragalinales" Vazquez-Campos et al. 2021 (LFWA-II) * Phylum Nanobdellota Huber et al. 2023 ** Class Nanobdellia Kato et al. 2022 *** Order JAPDLS01 *** Order " Jingweiarchaeales" Rao et al. 2023 TBS01*** Order Nanobdellales Kato et al. 2022 *** Order " Pacearchaeales" (DHVE-5, DUSEL-1) *** Order " Parvarchaeales" Rinke et al. 2020 (ARMAN 4 & 5) *** Order " Tiddalikarchaeales" Vazquez-Campos et al. 2021 (LFW-252_1) *** Order " Woesearchaeales" (DHVE-6) * Phylum ?" Mamarchaeota" * Order ?" Wiannamattarchaeales"

References

{{Taxonbar, from=Q24862848 Archaea taxa Extremophiles Kingdoms (biology)

Characteristics

Classification

Phylogeny

Taxonomy

See also

References