# Thermococcus celer
**Thermococcus celer** is a species of hyperthermophilic archaeon in the family Thermococcaceae, the founding and type species of the genus *Thermococcus* and one of the first members of the order [Thermococcales](https://www.edgepedia.org/thermococcales) to be described.[1](https://www.lpsn.dsmz.de/species/thermococcus-celer) • [2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) It was discovered in 1982 by Wolfram Zillig from samples taken by Karl Stetter during a trip to Vulcano, Italy, an event that marked the beginning of a novel field of archaeal research.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) The species grows optimally at 88 °C, pH 5.8, and 3.8 g/l NaCl, and its archaebacterial identity was established by the absence of murein, the presence of polyisopranyl alcohols in the membrane, and the properties of its DNA-dependent RNA polymerase.[3](https://pubmed.ncbi.nlm.nih.gov/23196302/)
| Key fact | Detail |
|---|---|
| Discovery | Isolated in 1982 by Wolfram Zillig from samples taken by Karl Stetter at Vulcano, Italy; founding member of the Thermococcales[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) |
| Nomenclature | Validly published as *Thermococcus celer* Zillig 1983; the epithet *celer* is Latin for fast, due to its high growth rate; nomenclatural type of the genus *Thermococcus*[1](https://www.lpsn.dsmz.de/species/thermococcus-celer) |
| Growth optima | 88 °C temperature, pH 5.8, 3.8 g/l NaCl[3](https://pubmed.ncbi.nlm.nih.gov/23196302/) |
| Archaeal traits | No murein; polyisopranyl alcohols in the membrane; rifampicin-resistant DNA-dependent RNA polymerase; insensitive to streptomycin and vancomycin[3](https://pubmed.ncbi.nlm.nih.gov/23196302/) |
| Type strain | ATCC 35543; DSM 2476; JCM 8558 (strain Vu 13)[1](https://www.lpsn.dsmz.de/species/thermococcus-celer) • [4](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=1293037) |
| Genome | Complete genome of strain Vu 13 = JCM 8558 available as GenBank CP014854.1[5](https://www.ncbi.nlm.nih.gov/nuccore/CP014854) |
| Biosafety | Risk group 1 in Canadian, Swiss, and German classifications[1](https://www.lpsn.dsmz.de/species/thermococcus-celer) |
## Discovery and naming
The exploration of hyperthermophilic Archaea accelerated in the early 1980s, when Wolfram Zillig and Karl Stetter set out to find novel Archaea and to study DNA-dependent RNA polymerases in the few archaeal species known at the time.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) From Stetter's samples collected at Vulcano, Italy, Zillig isolated *Thermococcus celer* in 1982, and the description of the new genus and species was effectively published in *Systematic and Applied Microbiology* in 1983 by Zillig, Holz, Janekovic, Schafer, and Reiter.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) • [1](https://www.lpsn.dsmz.de/species/thermococcus-celer) The name was validated the same year on Validation List No. 11 of the *International Journal of Systematic Bacteriology*.[1](https://www.lpsn.dsmz.de/species/thermococcus-celer)
The species epithet reflects a practical observation: *celer* is the Latin masculine adjective for fast, chosen because of the organism's high growth rate.[1](https://www.lpsn.dsmz.de/species/thermococcus-celer) The genus name combines the Greek *thermê* (heat) with the Latinized *coccus*, for a coccus existing in a hot environment.[6](https://www.lpsn.dsmz.de/genus/thermococcus) As the type species, *T. celer* anchors the genus *Thermococcus*, which in turn is the nomenclatural type of the family Thermococcaceae and the class [Thermococci](https://www.edgepedia.org/thermococci).[1](https://www.lpsn.dsmz.de/species/thermococcus-celer) • [6](https://www.lpsn.dsmz.de/genus/thermococcus)
## Phylogenetic significance
The original 1983 description placed *T. celer* as a novel isolated genus within the thermophilic branch of the archaebacteria, based on the absence of immunochemical cross-reaction of its [RNA polymerase](https://www.edgepedia.org/rna-polymerase) with those of *Thermoproteus*, *Desulfurococcus*, *Sulfolobus*, and *Thermoplasma*, and on the extent of 16S rRNA cross-hybridization with DNAs of other thermoacidophiles.[3](https://pubmed.ncbi.nlm.nih.gov/23196302/) In 1988, Linda Achenbach-Richter and Carl R. Woese, a molecular phylogeneticist at the University of Illinois whose 16S rRNA framework defined the Archaea, published an analysis titled "Rooting the archaebacterial tree: the pivotal role of *Thermococcus celer* in archaebacterial evolution," giving the species a central place in early efforts to root the archaeal tree.[7](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=2264&mode=Info)
The order Thermococcales now comprises three genera, *Pyrococcus*, *Thermococcus*, and *Palaeococcus*, and most described species in the order belong to *Thermococcus*.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) Since the discovery of the first *Thermococcus*, *T. celer*, many additional species have been identified, including *T. gammatolerans*, *T. barophilus*, *T. onnurineus*, *T. nautilus*, *T. sibiricus*, *T. litoralis*, *T. chitonophagus*, *T. alcaliphilus*, *T. acidaminovorans*, and *T. kodakarensis*.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) The genus currently contains 41 child taxa with validly published, correct names.[6](https://www.lpsn.dsmz.de/genus/thermococcus)
## Physiology and growth
*T. celer* is an extremely thermophilic, anaerobic archaeon with an optimal growth temperature of 88 °C, an optimal pH of 5.8, and an optimal NaCl concentration of 3.8 g/l.[3](https://pubmed.ncbi.nlm.nih.gov/23196302/) [Growth medium](https://www.edgepedia.org/growth-medium) components and cultivation conditions for *T. celer* and *Pyrococcus woesei* were later optimized in a 1999 study, which formulated a culture medium based on marine water.[8](https://pubmed.ncbi.nlm.nih.gov/10520597/) Like other members of the genus, *T. celer* is an anaerobic heterotroph that ferments organic compounds, and growth of *Thermococcus* species is enhanced by elemental sulfur.[9](https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00968/full)
Intracellular solute accumulation in *T. celer* has been examined by nuclear magnetic resonance spectroscopy together with *T. litoralis*, *T. stetteri*, and *T. zilligii*, as part of work on how salinity and growth temperature shape the compatible solutes (low-molecular-weight organic compounds that accumulate under osmotic stress and are compatible with metabolism) of the genus; the study's data table lists *T. celer* at 87 °C and 4.0% NaCl.[10](https://journals.asm.org/doi/full/10.1128/aem.64.10.3591-3598.1998)
## Enzymes and biotechnological relevance
Thermococcales gained prominence for their thermostable enzymes, exemplified by the commercialization of Vent DNA polymerase from *Thermococcus litoralis* in 1990 and [Pfu DNA polymerase](https://www.edgepedia.org/pfu-dna-polymerase) from *Pyrococcus furiosus* in 1991.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/) *T. celer* itself contributes enzymes of industrial interest: a protease from *T. celer* has an optimal temperature of 95 °C (Klingberg et al., 1991),[11](https://krishikosh.egranth.ac.in/server/api/core/bitstreams/b05e6e39-660d-4e01-a735-2cd1196ef501/content) and the species is listed among the amylopullulanase-producing *Thermococcus* organisms, a group of enzymes whose thermophilic members show optimum activity between 80 °C and 100 °C and pH between 5.5 and 6.6.[12](https://www.ndl.ethernet.edu.et/bitstream/123456789/77778/1/Ramesh%20C.%20Ray_2017.pdf) Such enzymes are valued because high-temperature operation increases reaction rates, improves substrate solubility, and minimizes microbial contamination in applications such as starch processing, paper and textile processing, and biomass deconstruction.[13](https://febs.onlinelibrary.wiley.com/doi/10.1111/j.1742-4658.2007.05954.x)
## Genome
The complete genome of the type strain, *Thermococcus celer* Vu 13 = JCM 8558, was sequenced and deposited as GenBank accession CP014854.1, part of a 2018 project that produced complete genome sequences of 11 type species from the genus *Thermococcus* of hyperthermophilic and piezophilic archaea.[5](https://www.ncbi.nlm.nih.gov/nuccore/CP014854) • [4](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=1293037) NCBI classifies the species within the euryarchaeotes, with the full lineage Archaea; [Methanobacteriati](https://www.edgepedia.org/methanobacteriati); Methanobacteriota; Thermococci; Thermococcales; Thermococcaceae; *Thermococcus*.[7](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=2264&mode=Info) Across the Thermococcales, complete genomes range from about 1.5 to 3 Mbp, and the function of more than about 30% of the predicted proteome remains unknown.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/)
## References
1. [Thermococcus celer, LPSN (Leibniz Institute DSMZ)](https://www.lpsn.dsmz.de/species/thermococcus-celer)
2. [Galyon AM, Atomi H, Santangelo TJ (2025). The Thermococcales as a model system: historical perspectives and emerging tools. J Bacteriol.](https://pmc.ncbi.nlm.nih.gov/articles/PMC12713403/)
3. [Zillig W et al. (1983). The Archaebacterium Thermococcus celer Represents a Novel Genus within the Thermophilic Branch of the Archaebacteria. Syst Appl Microbiol 4:88-94, PubMed abstract.](https://pubmed.ncbi.nlm.nih.gov/23196302/)
4. [NCBI Taxonomy Browser: Thermococcus celer Vu 13 = JCM 8558](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=1293037)
5. [Thermococcus celer Vu 13 = JCM 8558, complete genome, GenBank CP014854.1](https://www.ncbi.nlm.nih.gov/nuccore/CP014854)
6. [Thermococcus Zillig 1983, LPSN genus entry](https://www.lpsn.dsmz.de/genus/thermococcus)
7. [NCBI Taxonomy Browser: Thermococcus celer (Taxonomy ID 2264)](https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=2264&mode=Info)
8. [Blamey J et al. (1999). Optimization of the growth conditions of the extremely thermophilic microorganisms Thermococcus celer and Pyrococcus woesei. J Microbiol Methods 38:169-175.](https://pubmed.ncbi.nlm.nih.gov/10520597/)
9. [Price MT, Fullerton H, Moyer CL (2015). Biogeography and evolution of Thermococcus isolates from hydrothermal vent systems of the Pacific. Front Microbiol 6:968.](https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00968/full)
10. [Effects of Temperature, Salinity, and Medium Composition on Compatible Solute Accumulation by Thermococcus spp. Appl Environ Microbiol 64:3591-3598 (1998).](https://journals.asm.org/doi/full/10.1128/aem.64.10.3591-3598.1998)
11. [Bioprospecting of thermotolerant bacteria (thesis), enzyme table citing Klingberg et al. (1991)](https://krishikosh.egranth.ac.in/server/api/core/bitstreams/b05e6e39-660d-4e01-a735-2cd1196ef501/content)
12. [Ray RC (2017). Microbial Enzyme Technology in Food Applications, chapter on amylopullulanases.](https://www.ndl.ethernet.edu.et/bitstream/123456789/77778/1/Ramesh%20C.%20Ray_2017.pdf)
13. [Unsworth LD, van der Oost J, Koutsopoulos S (2007). Hyperthermophilic enzymes: stability, activity and implementation strategies for high temperature applications. FEBS J.](https://febs.onlinelibrary.wiley.com/doi/10.1111/j.1742-4658.2007.05954.x)
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*Topic: Encyclopedia › Life and health › Microorganisms and fungi › Archaea › Archaeal taxonomy and diversity › Euryarchaeota › Thermococci and Archaeoglobi taxa › Thermococcus*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license