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...

, Thermococcus is a genus of extreme thermophile

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...

s in the family the Thermococcaceae

Thermococcaceae

In taxonomy, the Thermococcaceae are a family of the Thermococcales.- External links :...

.

They consist of gram-negative

Gram-negative

Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...

 spheres that move with flagella. They are organothrophic

Organotroph

An organotroph is an organism that obtains hydrogen or electrons from organic substrates . Antonym: Lithotroph- See also :* Lithotroph* Heterotroph* Primary nutritional groups...

 anaerobes, growing in temperatures above 70°C. They require elemental sulphur as electron acceptor

Electron acceptor

An electron acceptor is a chemical entity that accepts electrons transferred to it from another compound. It is an oxidizing agent that, by virtue of its accepting electrons, is itself reduced in the process....

 in these growth reactions, producing hydrogen sulphide (H₂S) and carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

(CO₂) Thermococcus coalescens is an example species which has cells that can fuse in culturing to produce monster single cells.