Methanocaldococcus
Scientific classification
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Binomial name
Methanocaldococcus sp. FS406-22 Cruz et. al 2012

Methanocaldococcus sp. FS406-22 is an archaea in the genus Methanocaldococcus.[1] It is an anaerobic, piezophilic, diazotrophic, hyperthermophilic marine archaeon. The 16S rRNA gene of Methanocaldococcus sp FS406-22, is almost 100% similar to that of Methanocaldococcus jannaschii [1] It was isolated from minimum temperature of this archaean at 92 degrees Celsius.[2] Methanocaldococcus sp. FS406-22 is able to withstand extreme temperatures of hydrothermal vent fluid due to its ability to fix nitrogen and reduce it from N2 to NH3, a process otherwise known as nitrogen fixation.[2]

History

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Discovery

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Methanocaldococcus sp. FS406-22 was isolated from deep-sea hydrothermal vent fluid. [3] Hydrothermal vents are located on the ocean floor where plates are moving tectonically apart for example volcano sites and by mid ocean ridges.[3] These mid ocean ridges provide a large supply of food for some aquatic marine animals.[3] This vent was located on the Juan de Fuca Ridge in the Pacific Ocean near volcanic activity.[1]  Mausmi P. Mehta and John A. Baross isolated strain FS406-22 in September 2004 during the New Millennum Observatory cruise.[2] The Thomas G. Thompson vessel made this cruise possible and journeyed off to the Axial Volcano.[2] A remotely operated vehicle (ROPOS) sampled vent fluid from marker 113 using a hydrothermal fluid and particle sampler (HFPS).[2] Marker 113 is a vent located at 1525 meters deep in the southeast corner of the caldera.[2] This vent was active before the last eruption of Axial Volcano in January 1998.[2]

Physiology and Metabolism

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Methanocaldococcus sp. FS406-22 is marine archaean considered anaerobic which means it does not need oxygen. It is also piezophilic meaning it is an extremophile that thrives under elevated pressure.[4] Methanocaldococcus sp. FS406-22 is diazotrophic meaning it fixes nitrogen.[5] Lastly, it is considered hyperthermophilic an extremophile that lives in an extremely hot environment like hydrothermal vent, which can range from 75 degrees Celsius to 110 degrees Celsius.[6] The optimal temperature of growth is about 90 degrees Celsius, allowing it to thrive near volcanoes.[2] Its genome size is 1.77 Million base pairs long and contains 1,893 protein-coding genes.[7] It has a Guanine and Cytosine (GC) content of 32.04% and is motile via flagella.[2] This particular strain of Methanocaldococcus is cocci in shape and not pathogenic to humans.[2] Strain FS406-22 has an anaerobic metabolism, nitrogen-fixing metabolism, and is methanogenic.[1] The electron acceptors consist of carbon dioxide, acetic acid, and nitrate.[1] The electron donors are glutamine and carboxylic groups.[1]

Genome and Phylogeny

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The 16S rRNA gene of Methanocaldococcus sp. FS406-22, is almost 100% similar to that of Methanocaldococcus jannaschii DSM 2661.[2] The only difference being that Methanocaldococcus sp. FS406-22 is a hyperthermophilic nitrogen fixing archaea and Methanocaldococcus jannaschii DSM 2661 is unable to fix nitrogen.[2] Other related species and strains of Methanocaldococcus that are not as closely related include: Methanococcus aeolicus, Methanocaldococcus fervens, Methanotorris igneus, Methanocaldococcus infernus, Methanocaldococcus jannaschii, Methanococcus maripaludis, Methanothermococcus okinawensis, Methanococcus vannielii, Methanococcus voltae, and Methanocaldococcus vulcanius.[8]

Significance

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Methanocaldococcus sp FS406-22 is able to grow in these temperature extremes due to it’s ability to fix nitrogen and reduce it from N2 to NH3 in an optimum of 92 degrees Celsius.[2] This is an extremely important discovery to the scientific community as this optimum reduction of 92 degrees Celsius is a total of 28 degrees Celsius higher than the current documented limit of biological nitrogen fixation.[2] This particular discovery has potential to reveal a much wider range of conditions for life not only, in the seafloor biosphere but also, other ecosystems that are nitrogen limited.

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Further reading

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References

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  1. ^ a b c d e f Cruz, Joseph; Liu, Yifeng; Liang, Yongjie; Zhou, You; Wilson, Michael; Dennis, Jonathan J.; Stothard, Paul; Domselaar, Gary Van; Wishart, David S. (2012-01-01). "BacMap: an up-to-date electronic atlas of annotated bacterial genomes". Nucleic Acids Research 40 (D1): D599–D604. doi:10.1093/nar/gkr1105. ISSN 0305-1048. PMC 3245156. PMID 22135301
  2. ^ a b c d e f g h i j k l m n ^ Mehta, Mausmi P.; Baross, John A. (2006-12-15). "Nitrogen Fixation at 92°C by a Hydrothermal Vent Archaeon". Science 314 (5806): 1783–1786. doi:10.1126/science.1134772. ISSN 0036-8075. PMID 17170307
  3. ^ a b c Sakata, Rie; Kabutomori, Ryo; Okano, Keiko; Mitsui, Hiromasa; Takemura, Akihiro; Miwa, Tetsuya; Yamamoto, Hiroyuki; Okano, Toshiyuki (2015-08-14). "Rhodopsin in the Dark Hot Sea: Molecular Analysis of Rhodopsin in a Snailfish, Careproctus rhodomelas , Living near the Deep-Sea Hydrothermal Vent". PLOS ONE. 10 (8): e0135888. doi:10.1371/journal.pone.0135888. ISSN 1932-6203. PMC 4537116. PMID 26275172.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  4. ^ Zeng, Xiang; Birrien, Jean-Louis; Fouquet, Yves; Cherkashov, Georgy; Jebbar, Mohamed; Querellou, Joël; Oger, Philippe; Cambon-Bonavita, Marie-Anne; Xiao, Xiang (2009-03-19). "Pyrococcus CH1, an obligate piezophilic hyperthermophile: extending the upper pressure-temperature limits for life". The ISME Journal. 3 (7): 873–876. doi:10.1038/ismej.2009.21. ISSN 1751-7362.
  5. ^ Allen, EE, Bartlett DH.  2004.  Piezophiles: microbial adaptation to the deep-sea environment. Extremophiles. 3( Gerday C, Glansdorff N, Eds.).:231-255., Oxford: Eolss Publishers Co Ltd
  6. ^ "Complete sequence of chromosome of Methanocaldococcus sp. FS406-22." Lucas S., Copeland A., Lapidus A., Cheng J.-F., Bruce D., Goodwin L., Pitluck S., Teshima H., Detter J.C., Han C., Tapia R., Larimer F., Land M., Hauser L., Kyrpides N., Mikhailova N., Sieprawska-Lupa M., Leigh J., Whitman W.B., Woyke T. Submitted (FEB-2010) to the EMBL/GenBank/DDBJ databases
  7. ^ Caspi, Ron; Altman, Tomer; Dreher, Kate; Fulcher, Carol A.; Subhraveti, Pallavi; Keseler, Ingrid M.; Kothari, Anamika; Krummenacker, Markus; Latendresse, Mario (2012-01-01). "The MetaCyc database of metabolic pathways and enzymes and the BioCyc collection of pathway/genome databases". Nucleic Acids Research. 40 (D1): D742–D753. doi:10.1093/nar/gkr1014. ISSN 0305-1048. PMC 3245006. PMID 22102576.
  8. ^ Nordberg, Henrik; Cantor, Michael; Dusheyko, Serge; Hua, Susan; Poliakov, Alexander; Shabalov, Igor; Smirnova, Tatyana; Grigoriev, Igor V.; Dubchak, Inna (2014-01-01). "The genome portal of the Department of Energy Joint Genome Institute: 2014 updates". Nucleic Acids Research. 42 (D1): D26–D31. doi:10.1093/nar/gkt1069. ISSN 0305-1048. PMC 3965075. PMID 24225321.