''Thermococcus kodakarensis'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

thermophilic A thermophile is an organism—a type of extremophile—that thrives at relatively high temperatures, between . Many thermophiles are archaea, though they can be bacteria or fungi. Thermophilic eubacteria are suggested to have been among the earl ...

archaea. The

type strain The International Code of Nomenclature of Prokaryotes (ICNP) 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, 2003. A short hist ...

''T. kodakarensis'' KOD1 is one of the best-studied members of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

History

''T. kodakarensis'' was isolated from a

solfatara A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...

near the shore of Kodakara Island,

Kagoshima , abbreviated to , is the capital city of Kagoshima Prefecture, Japan. Located at the southwestern tip of the island of Kyushu, Kagoshima is the largest city in the prefecture by some margin. It has been nicknamed the "Naples of the Eastern wor ...

, Japan. The isolate was originally named ''Pyrococcus kodakarensis'' KOD1, but reclassified as a species of ''Thermococcus'', based on

16S rRNA 16S rRNA may refer to: * 16S ribosomal RNA 16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The g ...

sequence. Early research with ''T. kodakarensis'' was directed mostly at its

thermostable In materials science and molecular biology, thermostability is the ability of a substance to resist irreversible change in its chemical or physical structure, often by resisting decomposition or polymerization, at a high relative temperature. ...

enzymes, but its relative ease of handling and genetic manipulation facilitated by

natural competence In microbiology, genetics, cell biology, and molecular biology, competence is the ability of a cell to alter its genetics by taking up extracellular ("naked") DNA from its environment in the process called transformation. Competence may be diff ...

has made it an attractive system for the study of several biological processes.

Properties

''T. kodakarensis'' cells are irregular

cocci A coccus (plural cocci) is any bacterium or archaeon that has a spherical, ovoid, or generally round shape. Bacteria are categorized based on their shapes into three classes: cocci (spherical-shaped), bacillus (rod-shaped) and spiral ( of whi ...

1–2 μm in diameter, often occurring in pairs, and are highly motile by means of lophotrichous archaella. The cell wall consists of a layer of diether and tetraether lipids, and an outer glycoprotein coat. ''T. kodakarensis'' is an

obligate anaerobe Obligate anaerobes are microorganisms killed by normal atmospheric concentrations of oxygen (20.95% O2). Oxygen tolerance varies between species, with some species capable of surviving in up to 8% oxygen, while others lose viability in environme ...

, and a

heterotroph 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 ...

, growing rapidly on a variety of organic substrates in the presence of elemental sulfur, producing hydrogen sulfide gas. The generation time is estimated to be 40 minutes under optimum conditions. The requirement for elemental sulfur is relieved when pyruvate or starch is used for growth. In the absence of sulfur,

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

is produced instead of hydrogen sulfide. Growth is possible at temperature ranging from 60–100 °C, with an optimum at 85 °C. Like other marine organisms, high salt concentrations are required for optimal growth, and cell lysis may occur in dilute solutions.

Genome

In 2005, the genome of ''T. kodakarensis'' KOD1 was fully sequenced. The genome consists of a single 2,088,737 base pair circular chromosome, encoding a predicted 2306 proteins.

History

Properties

Genome

References

Further reading