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

Thermotogota The Thermotogae is a class of kingdom Thermotogati and domain Bacteria. It's the sole class in the phylum Thermotogota. The class Thermotogae is composed of Gram-negative staining, anaerobic, and mostly thermophilic and hyperthermophilic bacter ...

''. Members of ''Thermotoga'' are

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

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

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, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

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 layer (sacculus) that surrounds the bacterial cytoplasmic membrane. The sugar component consists of alternating ...

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. Currently, they are considered the predominant phylum within the domain of bacteria. They are naturally found as pathogenic and free-living (non- parasitic) ...

, 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 (diaminopimelate) to produce CO2 and L-lysine, the essential amino acid. It employs the cofactor pyridoxal phospha ...

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 oxygenat ...

s with varying degrees of oxygen tolerance. They are capable of reducing elemental sulphur (S₀) to hydrogen sulphide. 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 ...

'' 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.

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. Stetter is an expert on microbial life at high temperatures. Career Stetter was born in Munich and studied biology at the Technical University of M ...

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 ...

. The

Neo-Latin Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...

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

Greek Greek may refer to: 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 of all kno ...

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).

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 share ...

): several studies have found it to be deep-branching (in Bergey's manual it appeared in fact in "Volume I: The

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 ...

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) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...

reservoir in the East Paris Basin,

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

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 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)

Footnotes

References

{{Taxonbar, from=Q2716367 Bacteria genera Thermotogota

Name

Members and relatives

Phylogeny

Footnotes

See also

References