''Thermotoga'' is a genus of the phylum ''

Thermotogota The Thermotogota are a phylum of the domain Bacteria. The phylum Thermotogota is composed of Gram-negative staining, anaerobic, and mostly thermophilic and hyperthermophilic bacteria.Gupta, RS (2014) The Phylum Thermotogae. The Prokaryotes 989-10 ...

''. Members of ''Thermotoga'' are

hyperthermophilic A hyperthermophile is an organism that thrives in extremely hot environments—from 60 °C (140 °F) upwards. An optimal temperature for the existence of hyperthermophiles is often above 80 °C (176 °F). Hyperthermophiles are often within the doma ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

whose cell is wrapped in a unique sheath-like outer membrane, called a "toga". The members of the phylum stain

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

as they possess a thin

peptidoglycan Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ...

in between two lipid bilayers, albeit both peculiar. The peptidoglycan is unusual as the crosslink is not only meso-diaminopimelate as occurs in

Pseudomonadota Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The ...

, but D-lysine.All proteinogenic amino acids have the L- configuration; in peptidoglycan some amino acids with the D- configuration are present.
Lysine is synthesised from meso-diaminopimelate by

Diaminopimelate decarboxylase The enzyme diaminopimelate decarboxylase () catalyzes the cleavage of carbon-carbon bonds in meso 2,6 diaminoheptanedioate to produce CO2 and L-lysine, the essential amino acid. It employs the cofactor pyridoxal phosphate, also known as PLP, wh ...

The species are

anaerobe An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenate ...

s with varying degrees of oxygen tolerance. They are capable of reducing elemental sulphur (S₀) to hydrogen sulphide, which in turn can be used. Whether thermophily is an innovation of the lineage or an ancestral trait is unclear and cannot be determined.
The genome of ''

Thermotoga maritima ''Thermotoga maritima'' is a hyperthermophilic, anaerobic organism that is a member of the order Thermotogales. ''T. maritima'' is well known for its ability to produce hydrogen (clean energy) and it is the only fermentative bacterium that has be ...

'' was sequenced in 1999, revealing several genes of archaeal origin, possibly allowing its thermophilic adaptation. The CG (cytosine-guanine) content of ''T. maritima'' is 46.2%; most thermophiles in fact have high CG content; this has led to the speculation that CG content may be a non-essential consequence to thermophily and not the driver towards thermophily.

Members and relatives

The precise relation of the ''Thermotogota'' to other phyla is debated (''v.''

bacterial phyla Bacterial phyla constitute the major lineages of the domain ''Bacteria''. While the exact definition of a bacterial phylum is debated, a popular definition is that a bacterial phylum is a monophyletic lineage of bacteria whose 16S rRNA genes ...

): several studies have found it to be deep-branching (in

Bergey's manual ''Bergey's Manual of Systematic Bacteriology'' is the main resource for determining the identity of prokaryotic organisms, emphasizing bacterial species, using every characterizing aspect. The manual was published subsequent to the ''Bergey's Manu ...

it appeared in fact in "Volume I: The

Archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...

and the deeply branching and phototrophic Bacteria"), while other have found ''Firmicutes'' to be deep-branching with ''Thermotogota'' clustering away from the base. The type species of the genus is ''T. maritima'', first described in 1986. At the time, it was the first species of the phylum to be described. The genus ''Thermotoga'' now contains three official species. Recently eight species were transferred out of the genus and most of them ended up within the genus '' Pseudothermotoga'' by Bhandari & Gupta 2014. ''T. subterranea'' strain SL1 was found in a 70 °C deep continental

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

reservoir in the East Paris Basin,

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

Name

The paper and the chapter in Bergey's manual were authored by several authors including the microbiologists

Karl Stetter Karl Otto Stetter (born 16 July 1941) is a German microbiologist and authority on astrobiology. He is an expert on microbial life at high temperatures. Career Stetter was born in Munich and studied biology at the Technical University of Munich ...

and

Carl Woese Carl Richard Woese (; July 15, 1928 – December 30, 2012) was an American microbiologist and biophysicist. Woese is famous for defining the Archaea (a new domain of life) in 1977 through a pioneering phylogenetic taxonomy of 16S ribosomal RNA, ...

. The

new Latin New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...

feminine name "thermotoga" means "the hot outer garment", being a combination of the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

noun θέρμη (''therme'', heat) or more correctly the adjective θερμός, ή, όν (''thermos, e, on'', hot) and the Latin feminine noun ''

toga The toga (, ), a distinctive garment of ancient Rome, was a roughly semicircular cloth, between in length, draped over the shoulders and around the body. It was usually woven from white wool, and was worn over a tunic. In Roman historical tra ...

'' (the Roman outer garment).

Phylogeny

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 Nomenclature ...

(LPSN) and

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the United States 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)

Footnotes

References

{{Taxonbar, from=Q2716367 Bacteria genera Thermotogota ca:Thermotoga

Members and relatives

Name

Phylogeny

Footnotes

See also

References