In taxonomy

Alpha taxonomy

Alpha taxonomy is the discipline concerned with finding, describing and naming species of living or fossil organisms. This field is supported by institutions holding collections of these organisms, with relevant data, carefully curated: such institutes include natural history museums, herbaria and...

, Thermoproteus is a genus of the Thermoproteaceae

Thermoproteaceae

In taxonomy, the Thermoproteaceae are a family of the Thermoproteales.-External links:...

.These prokaryotes are thermophilic

Thermophile

A thermophile is an organism — a type of extremophile — that thrives at relatively high temperatures, between 45 and 122  °C . Many thermophiles are archaea...

 sulphur-dependent organisms related to the genera Sulfolobus, Pyrodictium and Desulfurococcus. They are hydrogen-sulphur autotrophs and can grow at temperatures of up to 95 degrees Celsius

Celsius

Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...

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Description and significance

Thermoproteus is a genus of anaerobes that grow in the wild by autotrophic sulfur reduction. Like other hyperthermophiles, Thermoproteus represents a living example of some of Earth's earliest organisms, located at the base of the Archaea.

Genome structure

Genetic sequencing of Thermoproteus has revealed much about the organism's modes of metabolism. Total genome length is 1.84 Mbp, and the DNA is double-stranded and circular. Genes are arranged in co-transcribed clusters called operons. The Thermoproteus tenax genome has been completely sequenced.

Cell structure and metabolism

A significant amount of research has been done on the metabolism of Thermoproteus and other hyperthermophiles as well. Thermoproteus metabolizes autotrophically through sulfur reduction, but it grows much faster by sulfur respiration in cultivation. In T. tenax, a number of metabolic pathways allow the cell to select a mode of metabolism depending on the energy requirements of the cell (depending, for example, on the cell's developmental or growth stage). Like all archaeans, Thermoproteus possesses unique membrane lipids, which are ether-linked glycerol derivatives of 20 or 40 carbon branched lipids. The lipids' unsaturations are generally conjugated (as opposed to the unconjugation found in Bacteria and Eukaryota). In Thermosphaera, as in all members of the Crenarchaeota, the membranes are predominated by the 40-carbon lipids that span the entire membrane. This causes the membrane to be composed of monolayers with polar groups at each end. The cells are rod-shaped with diameters of up to 4 micrometres and up to 100 micrometres in length, and reproduce by developing branches on the end of the cell which grow into individual cells. They are motile by flagella.

Ecology

Members of Thermoproteus are found in acidic hot springs and water holes; they have been isolated in these habitats in Iceland, Italy, North America, New Zealand, the Azores, and Indonesia. Their optimal growth temperature is 85C
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