Thermococcus barophilus | |
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Species: | T. barophilus |
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Thermococcus barophilus Marteinsson et al. 1999 | |
Thermococcus barophilus is a piezophilic and hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent. It is anaerobic and sulfur-metabolising, with type strain MPT. [1]
The name Thermococcus barophilus has Greek roots, thermo for heat, kokkos for the spherical cells, baros for weight, and philos for loving. Overall, the name means "organism with a spherical body that gravitates to heat and to the pressure of the water column." [2]
T. barophilus can grow at even higher temperatures if the pressure is high, as well. At an atmospheric pressure, it can grow at temperatures of 45–90 °C, with an optimal temperature of 85 °C, but it can grow at temperatures as high as 100 °C if the hydrostatic pressure is 15.0–17.5 MPa. [2] Sulfur is necessary for its growth, but it can also grow slowly in absence of sulfur. Membrane lipid has a major archaeol component. [3]
The genome of T. barophilus has been sequenced and is circular in nature with a size of 2,010,078bp. It has also a circular plasmid pTBMP1. The genome sequence shows that it has the carboxydotrophic pathway and bears seven different hydrogenase complexes. [4]
The transcriptome analysis of this organism has also been done. It has been found that, 378 genes are differentially expressed in T. barophilus under different pressure conditions. Genes related to energy production and conversion, inorganic ion transport and metabolism and crabohydrate transport and metabolism are upregulated. Genes which are downregulated are involved in amino acid transport and metabolism, nucleotide transport and metabolism, replication and repair and recombination and inorganic ion transport and metabolism. [5]
An extremophile is an organism that is able to live in extreme environments, i.e. environments with conditions approaching or expanding the limits of what known life can adapt to, such as extreme temperature, radiation, salinity, or pH level.
Archaeoglobaceae are a family of the Archaeoglobales. All known genera within the Archaeoglobaceae are hyperthermophilic and can be found near undersea hydrothermal vents. Archaeoglobaceae are the only family in the order Archaeoglobales, which is the only order in the class Archaeoglobi.
A piezophile is an organism with optimal growth under high hydrostatic pressure i.e. an organism that has its maximum rate of growth at a hydrostatic pressure equal to or above 10 MPa, when tested over all permissible temperatures. Originally, the term barophile was used for these organisms, but since the prefix "baro-" stands for weight, the term piezophile was given preference. Like all definitions of extremophiles, the definition of piezophiles is anthropocentric, and humans consider that moderate values for hydrostatic pressure are those around 1 atm, whereas those "extreme" pressures are the normal living conditions for those organisms. Hyperpiezophiles are organisms that have their maximum growth rate above 50 MPa.
Pyrococcus furiosus is a heterotrophic, strictly anaerobic, extremophilic, model species of archaea. It is classified as a hyperthermophile because it thrives best under extremely high temperatures, and is notable for having an optimum growth temperature of 100 °C. P. furiosus belongs to the Pyrococcus genus, most commonly found in extreme environmental conditions of hydrothermal vents. It is one of the few prokaryotic organisms that has enzymes containing tungsten, an element rarely found in biological molecules.
Methanococcus is a genus of coccoid methanogens of the family Methanococcaceae. They are all mesophiles, except the thermophilic M. thermolithotrophicus and the hyperthermophilic M. jannaschii. The latter was discovered at the base of a “white smoker” chimney at 21°N on the East Pacific Rise and it was the first archaeal genome to be completely sequenced, revealing many novel and eukaryote-like elements.
In taxonomy, the Thermococci are a class of microbes within the Euryarchaeota.
In taxonomy, Thermococcus is a genus of thermophilic Archaea in the family the Thermococcaceae.
Thermococcus litoralis is a species of Archaea that is found around deep-sea hydrothermal vents as well as shallow submarine thermal springs and oil wells. It is an anaerobic organotroph hyperthermophile that is between 0.5–3.0 μm (20–118 μin) in diameter. Like the other species in the order thermococcales, T. litoralis is an irregular hyperthermophile coccus that grows between 55–100 °C (131–212 °F). Unlike many other thermococci, T. litoralis is non-motile. Its cell wall consists only of a single S-layer that does not form hexagonal lattices. Additionally, while many thermococcales obligately use sulfur as an electron acceptor in metabolism, T. litoralis only needs sulfur to help stimulate growth, and can live without it. T. litoralis has recently been popularized by the scientific community for its ability to produce an alternative DNA polymerase to the commonly used Taq polymerase. The T. litoralis polymerase, dubbed the vent polymerase, has been shown to have a lower error rate than Taq but due to its proofreading 3’–5’ exonuclease abilities.
Thermococcus celer is a Gram-negative, spherical-shaped archaeon of the genus Thermococcus. The discovery of T. celer played an important role in rerooting the tree of life when T. celer was found to be more closely related to methanogenic Archaea than to other phenotypically similar thermophilic species. T. celer was the first archaeon discovered to house a circularized genome. Several type strains of T. celer have been identified: Vu13, ATCC 35543, and DSM 2476.
Thermococcus gammatolerans is an archaea extremophile and the most radiation-resistant organism known to exist.
Thermococcus kodakarensis is a species of thermophilic archaea. The type strain T. kodakarensis KOD1 is one of the best-studied members of the genus.
Pyrococcus abyssi is a hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent in the North Fiji Basin at 2,000 metres (6,600 ft). It is anaerobic, sulfur-metabolizing, gram-negative, coccus-shaped and highly motile. Its optimum growth temperature is 96 °C (205 °F). Its type strain is GE5. Pyrococcus abyssi has been used as a model organism in studies of DNA polymerase. This species can also grow at high cell densities in bioreactors.
Palaeococcus ferrophilus is a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney. It cells are irregular cocci and motile with multiple polar flagella.
Thermococcus profundus is a hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent. It is coccoid-shaped with 1–2 μm in diameter, designated as strain DT5432.
Thermococcus alcaliphilus is a hyperthermophilic archaeon. It is coccoid-shaped and heterotrophic, first isolated from a shallow marine hydrothermal system at Vulcano Island, Italy. Its type strain is AEDII12.
Thermococcus peptonophilus is a fast-growing hyperthermophilic archaeon. It is coccus-shaped, obligately anaerobic and about 0.7–2 μm in diameter. It is a strict anaerobe and grows exclusively on complex substrates, such as peptone, casein, tryptone, and yeast extract. It cannot use carbon dioxide as a source of carbon. Although it can grow somewhat in the absence of elemental sulfur, it prefers sulfur.
Desulfurobacterium thermolithotrophum is a species of autotrophic, sulphur-reducing bacterium isolated from a deep-sea hydrothermal vent. It is the type species of its genus, being thermophilic, anaerobic, Gram-negative, motile and rod-shaped, with type strain BSAT.
Thermococcus hydrothermalis is a hyperthermophilic archaeon. It is strictly anaerobic and coccus-shaped, and its cells range from 0.8 to 2.0 μm in diameter, with type strain AL662T. It was isolated from a hydrothermal vent in the East Pacific Rise. This species is notable for its α-glucosidase, which functions optimally at a temperature of 110 °C.
Marinitoga piezophila is a species of rod-shaped, thermo-piezophilic bacteria. It is, anaerobic, chemo-organotrophic, sulfur-reducing, motile, have a mean length of 1-1.5 micrometres and stains Gram-negative. The type strain is KA3T.