Haloarchaea

Haloarchaea
Halobacterium sp. strain NRC-1, each cell about 5 µm in length.
Scientific classification
Domain: Archaea
Kingdom: Euryarchaeota
Phylum: Euryarchaeota
Class: Halobacteria
Grant et al. 2002
Order
Synonyms
  • Halomebacteria Cavalier-Smith 2002
  • Haloarchaea

Haloarchaea (halophilic archaea, halophilic archaebacteria, halobacteria)[1] are a class of the Euryarchaeota,[2] found in water saturated or nearly saturated with salt. Halobacteria are now recognized as archaea, rather than bacteria and are one of the largest groups. The name 'halobacteria' was assigned to this group of organisms before the existence of the domain Archaea was realized, and remains valid according to taxonomic rules. In a non-taxonomic context, halophilic archaea are referred to as haloarchaea to distinguish them from halophilic bacteria.

These microorganisms are members of the halophile community, in that they require high salt concentrations to grow, with most species requiring more than 2.0M NaCl for growth and survival. They are a distinct evolutionary branch of the Archaea distinguished by possession of ether-linked lipids and the absence of murein in their cell walls.

Haloarchaea can grow aerobically or anaerobically. Parts of the membranes of haloarchaea are purplish in color, and large blooms of haloarchaea appear reddish, from the pigment bacteriorhodopsin, related to the retinal pigment rhodopsin, which it uses to transform light energy into chemical energy by a process unrelated to chlorophyll-based photosynthesis.

Haloarchaea have a potential to solubilize phosphorus. Phosphorus-solubilizing halophilic archaea may well play a role in P (phosphorus) nutrition to vegetation growing in hypersaline soils. Haloarchaea may also have application as inoculants for crops growing in hypersaline regions.[3]

Taxonomy

The extremely halophilic, aerobic members of Archaea are classified within the family Halobacteriaceae, order Halobacteriales in Class III. Halobacteria of the phylum Euryarchaeota (International Committee on Systematics of Prokaryotes, Subcommittee on the taxonomy of Halobacteriaceae). As of May 2016, the family Halobacteriaceae comprises 213 species in 50 genera.

Domain: Archaea

Euryarchaeota

  • Halobacteria
    • Halobacteriales
      • Halobacteriaceae
        • Haladaptatus [Hap.]
          • Haladaptatus cibarius
          • Haladaptatus litoreus
          • Haladaptatus pallidirubidus
          • Haladaptatus paucihalophilus (Type species)
        • Halalkalicoccus [Hac.]
          • Halalkalicoccus jeotgali
          • Halalkalicoccus paucihalophilus
          • Halalkalicoccus tibetensis (Type species)
        • "Halanaeroarchaeum" ["Haa".]
          • "Halanaeroarchaeum sulfurireducens" (Type species) (IJSEM, in press)
        • Halapricum [Hpr.]
          • Halapricum salinum (Type species)
        • Halarchaeum [Hla.]
          • Halarchaeum acidiphilum (Type species)
          • Halarchaeum grantii
          • Halarchaeum nitratireducens
          • Halarchaeum rubridurum
          • Halarchaeum salinum
          • Halarchaeum solikamskense
        • Haloarchaeobius [Hab.]
          • Haloarchaeobius amylolyticus
          • Haloarchaeobius baliensis
          • Haloarchaeobius iranensis (Type species)
          • Haloarchaeobius litoreus
          • Haloarchaeobius salinus
        • Haloarcula [Har.]
          • Haloarcula amylolytica
          • Haloarcula argentinensis
          • Haloarcula hispanica
          • Haloarcula japonica
          • Haloarcula marismortui
          • Haloarcula quadrata
          • Haloarcula salaria
          • Haloarcula tradensis
          • Haloarcula vallismortis (Type species)
        • Halobacterium [Hbt.] (Type genus)
          • Halobacterium jilantaiense
          • Halobacterium noricense
          • "Halobacterium piscisalsi" (subjective junior synonym of Halobacterium salinarum)[4]
          • Halobacterium ruburm
          • Halobacterium salinarum (Type species)
        • Halobaculum [Hbl.]
          • Halobaculum gomorrense (Type species)
          • Halobaculum magnesiiphilum
        • Halobellus [Hbs.]
          • Halobellus clavatus (Type species)
          • Halobellus inordinatus
          • Halobellus limi
          • Halobellus litoreus
          • Halobellus ramosii
          • Halobellus rarus
          • Halobellus rufus
          • Halobellus salinus
        • Halobiforma [Hbf.]
          • Halobiforma haloterrestris (Type species)
          • Halobiforma lacisalsi
          • Halobiforma nitratireducens
        • Halocalculus [Hcl.]
          • Halocalculus aciditolerans (Type species)
        • Halococcus [Hcc.]
          • Halococcus agarilyticus
          • Halococcus dombrowskii
          • Halococcus hamelinensis
          • Halococcus morrhuae (Type species)
          • Halococcus qingdaonensis
          • Halococcus saccharolyticus
          • Halococcus salifodinae
          • Halococcus sediminicola
          • Halococcus thailandensis
        • Haloferax [Hfx.]
          • Haloferax alexandrinus
          • Haloferax chudinovii
          • Haloferax denitrificans
          • Haloferax elongans
          • Haloferax gibbonsii
          • Haloferax larsenii
          • Haloferax lucentense
          • Haloferax mediterranei
          • Haloferax mucosum
          • Haloferax prahovense
          • Haloferax sulfurifontis
          • Haloferax volcanii (Type species)
        • Halogeometricum [Hgm.]
          • Halogeometricum borinquense (Type species)
          • Halogeometricum limi
          • Halogeometricum pallidum
          • Halogeometricum rufum
        • Halogranum [Hgn.]
          • Halogranum amylolyticum
          • Halogranum gelatinilyticum
          • Halogranum rubrum (Type species)
          • Halogranum salarium
        • Halohasta [Hht.]
          • Halohasta litorea (Type species)
          • Halohasta litchfieldiae
        • Halolamina [Hlm.]
          • Halolamina pelagica (Type species)
          • Halolamina rubra
          • Halolamina salifodinae
          • Halolamina salina
          • Halolamina sediminis
        • Halomarina [Hmr.]
          • Halomarina oriensis (Type species)
        • Halomicroarcula [Hma.]
          • Halomicroarcula limicola
          • Halomicroarcula pellucida (Type species)
          • Halomicroarcula salina
        • Halomicrobium [Hmc.]
          • Halomicrobium katesii
          • Halomicrobium mukohataei (Type species)
          • Halomicrobium zhouii
        • Halonotius [Hns.]
          • Halonotius pteroides (Type species)
        • "Haloparvum" ["Hpv".]
          • "Haloparvum sedimenti" (Type species) (IJSEM, in press)
        • Halopelagius [Hpl.]
          • Halopelagius inordinatus (Type species)
          • Halopelagius fulvigenes
          • Halopelagius longus
        • Halopenitus [Hpt.]
          • Halopenitus malekzadehii
          • Halopenitus persicus (Type species)
          • Halopenitus salinus
        • Halopiger [Hpg.]
          • Halopiger aswanensis
          • Halopiger salifodinae
          • Halopiger xanaduensis (Type species)
        • Haloplanus [Hpn.]
          • Haloplanus aerogenes
          • Haloplanus litoreus
          • Haloplanus natans (Type species)
          • Haloplanus ruber
          • Haloplanus salinus
          • Haloplanus vescus
        • Haloquadratum [Hqr.]
          • Haloquadratum walsbyi (Type species)
        • Halorhabdus [Hrd.]
          • Halorhabdus tiamatea
          • Halorhabdus utahensis (Type species)
          • "Halorhabdus rudnickae" (Syst Appl Microbiol., in press)
        • Halorientalis [Hos.]
          • Halorientalis brevis
          • Halorientalis persicus
          • Halorientalis regularis (Type species)
        • Halorubellus [Hrb.]
          • Halorubellus litoreus
          • Halorubellus salinus (Type species)
        • Halorubrum [Hrr.]
          • Halorubrum aquaticum
          • Halorubrum aidingense
          • Halorubrum alkaliphilum
          • Halorubrum arcis
          • Halorubrum californiense
          • Halorubrum chaoviator
          • Halorubrum cibi
          • Halorubrum coriense
          • Halorubrum distributum
          • Halorubrum ejinorense
          • Halorubrum ezzemoulense
          • Halorubrum gandharaense
          • Halorubrum halodurans
          • Halorubrum halophilum
          • Halorubrum kocurii
          • Halorubrum lacusprofundi
          • Halorubrum laminariae
          • Halorubrum lipolyticum
          • Halorubrum litoreum
          • Halorubrum luteum
          • Halorubrum orientale
          • Halorubrum persicum
          • Halorubrum rubrum
          • "Halorubrum rutilum" (Arch Microbiol.,2015, 197(10):1159-1164)
          • Halorubrum saccharovorum (Type species)
          • Halorubrum salinum
          • Halorubrum sodomense
          • Halorubrum tebenquichense
          • Halorubrum terrestre
          • Halorubrum tibetense
          • Halorubrum trapanicum
          • Halorubrum vacuolatum
          • Halorubrum yunnanense
          • Halorubrum xinjiangense
        • Halorussus [Hrs.]
          • Halorussus amylolyticus
          • Halorussus rarus
          • Halorussus ruber
        • "Halosiccatus" ["Hsc".]
          • "Halosiccatus urmianus" (Type species) (IJSEM, in press)
        • Halosimplex [Hsx.]
          • Halosimplex carlsbadense (Type species)
          • Halosimplex litoreum
          • Halosimplex pelagicum
          • Halosimplex rubrum
        • Halostagnicola [Hst.]
          • Halostagnicola alkaliphila
          • Halostagnicola bangensis
          • Halostagnicola kamekurae
          • Halostagnicola larsenii (Type species)
        • "Halostella" ["Hsl".]
          • "Halostella salina" (Type species) (IJSEM, in press)
        • Haloterrigena [Htg.]
          • Haloterrigena daqingensis
          • Haloterrigena hispanica
          • Haloterrigena jeotgali
          • Haloterrigena limicola
          • Haloterrigena longa
          • Haloterrigena saccharevitans
          • Haloterrigena salina
          • Haloterrigena thermotolerans
          • Haloterrigena turkmenica (Type species)
        • Halovarius [Hvr.]
          • Halovarius luteus (Type species)
        • Halovenus [Hvn.]
          • Halovenus aranensis (Type species)
          • Halovenus rubra
          • Halovenus salina
        • Halovivax [Hvx.]
          • Halovivax asiaticus (Type species)
          • Halovivax cerinus
          • Halovivax limisalsi
          • Halovivax ruber
        • Natrialba [Nab.]
          • Natrialba aegyptia
          • Natrialba asiatica (Type species)
          • Natrialba chahannaoensis
          • Natrialba hulunbeirensis
          • Natrialba magadii
          • Natrialba taiwanensis
        • Natribaculum [Nbl.]
          • Natribaculum breve (Type species)
          • Natribaculum longum
        • Natrinema [Nnm.]
          • Natrinema altunense
          • Natrinema ejinorense
          • Natrinema gari
          • Natrinema pallidum
          • Natrinema pellirubrum (Type species)
          • Natrinema salaciae
          • Natrinema versiforme
        • Natronoarchaeum [Nac.]
          • Natronoarchaeum mannanilyticum (Type species)
          • Natronoarchaeum philippinense
          • Natronoarchaeum rubrum
        • Natronobacterium [Nbt.]
          • Natronobacterium gregoryi (Type species)
          • Natronobacterium texcoconense
        • Natronococcus [Ncc.]
          • Natronococcus amylolyticus
          • Natronococcus jeotgali
          • Natronococcus occultus (Type species)
          • Natronococcus roseus
        • Natronolimnobius [Nln.]
          • Natronolimnobius baerhuensis (Type species)
          • Natronolimnobius innermongolicus
        • Natronomonas [Nmn.]
          • Natronomonas gomsonensis
          • Natronomonas moolapensis
          • Natronomonas pharaonis (Type species)
        • Natronorubrum [Nrr.]
          • Natronorubrum aibiense
          • Natronorubrum bangense (Type species)
          • Natronorubrum sediminis
          • Natronorubrum sulfidifaciens
          • Natronorubrum texcoconense
          • Natronorubrum tibetense
        • Salarchaeum [Sar.]
          • Salarchaeum japonicum (Type species)
        • Salinarchaeum [Saa.]
          • Salinarchaeum laminariae (Type species)
        • Salinigranum [Sgn.]
          • Salinigranum rubrum (Type species)
        • Salinirubrum [Srr.]
          • Salinirubrum litoreum (Type species)

non-valid

  • "Halorubrum sfaxense"
  • "Candidatus Halobonum tyrrellensis[5]。
  • "Candidatus Haloectosymbiotes riaformosensis"[6]。
  • "Halopiger djelfamassiliensis sp"[7]。
  • "Halopiger goleamassiliensis"[8]。
  • "Haloferax namakaokahaiae"[9]。
  • "Halorubrum tropicale"[10]。
  • "Haloarcula rubripromontorii"[11]。
  • "Halobacterium hubeiense"[12]。

Classification of Gupta et al.[13][14]

Halobacteriales

  • Halobacteriaceae (Type genera: Halobacterium)
　　

Haladaptatus, Halalkalicoccus, Haloarchaeobius, Halarchaeum, Halobacterium, Halocalculus, Halorubellus, Halorussus, "Halosiccatus", Halovenus, Natronoarchaeum, Natronomonas, Salarchaeum.

  • Haloarculaceae (Type genera: Haloarcula)
　　

Halapricum, Haloarcula, Halomicroarcula, Halomicrobium, Halorientalis, Halorhabdus, Halosimplex.

  • Halococcaceae (Type genera: Halococcus)
　　

Halococcus.

Haloferacales

  • Haloferacaceae (Type genera: Haloferax)
　　

Halabellus, Haloferax, Halogeometricum, (Halogranum), Halopelagius, Haloplanus, Haloquadratum, Halosarcina.

  • Halorubraceae (Type genera: Halorubrum)
　　

Halobaculum, (Halogranum), Halohasta, Halolamina, Halonotius, Halopenitus, Halorubrum, Salinigranum.

Natrialbales

  • Natrialbaceae (Type genera: Natrialba)
　　

Halobiforma, Halopiger, Halostagnicola, Haloterrigena, Halovarius, Halovivax, Natrialba, Natribaculum, Natronobacterium, Natronococcus, Natronolimnobius, Natronorubrum, Salinarchaeum.

Living environment

Salt ponds with pink colored Haloarchaea

Haloarchaea require salt concentrations in excess of 2 M (or about 10%) to grow, and optimal growth usually occurs at much higher concentrations, typically 20–25%. However, Haloarchaea can grow up to saturation (about 37% salts).[15]

Haloarchaea are found mainly in hypersaline lakes and solar salterns. Their high densities in the water often lead to pink or red colourations of the water (the cells possessing high levels of carotenoid pigments, presumably for UV protection).[16]

Adaptations to environment

Haloarchaea can grow at an aw close to 0.75, yet a water activity (aw) lower than 0.90 is inhibitory to most microbes.[17] The number of solutes causes osmotic stress on microbes, which can cause cell lysis, unfolding of proteins and inactivation of enzymes when there is a large enough imbalance.[18] Haloarchaea combat this by retaining compatible solutes such as potassium chloride (KCl) in their intracellular space to allow them to balance osmotic pressure.[19] Retaining these salts is referred to as the “salt-in” method where the cell accumulates a high internal concentration of potassium.[20] Because of the elevated potassium levels, haloarchaea have specialized proteins that have a highly negative surface charge to tolerate high potassium concentrations.[21]

Haloarchaea have adapted to use glycerol as a carbon and energy source in catabolic processes, which is often present in high salt environments due to Dunaliella species that produce glycerol in large quantities.[22][23]

Phototrophy

Bacteriorhodopsin is used to absorb light, which provides energy to transport protons (H+) across the cellular membrane. The concentration gradient generated from this process can then be used to synthesize ATP. Many haloarchaea also possess related pigments, including halorhodopsin, which pumps chloride ions in the cell in response to photons, creating a voltage gradient and assisting in the production of energy from light. The process is unrelated to other forms of photosynthesis involving electron transport however, and haloarchaea are incapable of fixing carbon from carbon dioxide.

Cellular shapes

Haloarchaea are often considered pleomorphic, or able to take on a range of shapes—even within a single species. This makes identification by microscopic means difficult, and it is now more common to use gene sequencing techniques for identification instead.

One of the more unusually shaped Haloarchaea is the "Square Haloarchaeon of Walsby". It was classified in 2004 using a very low nutrition solution to allow growth along with a high salt concentration, square in shape and extremely thin (like a postage stamp). This shape is probably only permitted by the high osmolarity of the water, permitting cell shapes that would be difficult, if not impossible, under other conditions.

As exophiles

Haloarchaea have been proposed as a kind of life that could live on Mars; since the Martian atmosphere has a pressure below the triple point of water, freshwater species would have no habitat on the Martian surface.[24]

See also

References

  1. ↑ Fendrihan, Sergiu; Legat, Andrea; Pfaffenhuemer, Marion; Gruber, Claudia; Weidler, Gerhard; Gerbl, Friedrich; Stan-Lotter, Helga (19 July 2006). "Extremely halophilic archaea and the issue of long-term microbial survival". Reviews in Environmental Science and Bio/Technology. 5 (2–3): 203–218. doi:10.1007/s11157-006-0007-y. PMC 3188376.
  2. ↑ See the NCBI webpage on Halobacteria. Data extracted from the "NCBI taxonomy resources". National Center for Biotechnology Information. Retrieved 2007-03-19.
  3. ↑ Yadav, Ajar Nath; Sharma, Divya; Gulati, Sneha; Singh, Surender; Dey, Rinku; Pal, Kamal Krishna; Kaushik, Rajeev; Saxena, Anil Kumar (2015-07-28). "Haloarchaea Endowed with Phosphorus Solubilization Attribute Implicated in Phosphorus Cycle". Scientific Reports. 5. Bibcode:2015NatSR...512293Y. doi:10.1038/srep12293. ISSN 2045-2322. PMC 4516986. PMID 26216440.
  4. ↑ Minegishi, H., Echigo, A., Shimane, Y., Kamekura, M., Tanasupawat, S., Visessanguan, W., Usami, R. (2012) "Halobacterium piscisalsi Yachai et al. 2008 is later heterotypic synonym of Halobacterium salinarum Elazari-Volcani 1957." Int J Syst Evol Microbiol. 62: 2160-2162
  5. ↑ Ugalde JA, Narasingarao P, Kuo S, Podell S, Allen EE. (2013) Draft Genome Sequence of "Candidatus Halobonum tyrrellensis" Strain G22, Isolated from the Hypersaline Waters of Lake Tyrrell, Australia. Genome Announc. 12;1(6).
  6. ↑ Filker S, Kaiser M, Rosselló-Móra R, Dunthorn M, Lax G, Stoeck T. (2014) "Candidatu Haloectosymbiotes riaformosensis" (Halobacteriaceae), an archaeal ectosymbiont of the hypersaline ciliate Platynematum salinarum. Syst Appl Microbiol. 37(4):244-251.
  7. ↑ Hassani II, Robert C, Michelle C, Raoult D, Hacène H, Desnues C. (2013) Non-contiguous finished genome sequence and description of Halopiger djelfamassiliensis sp. nov.Stand Genomic Sci. 9(1):160-174.
  8. ↑ Ikram HI, Catherine R, Caroline M, Didier R, Hocine H, Christelle D. (2014) Non-contiguous finished genome sequence and description of Halopiger goleamassiliensis sp. nov.Stand Genomic Sci. 9(3):956-959.
  9. ↑ McDuff S, King GM, Neupane S, Myers MR. (2016) Isolation and characterization of extremely halophilic CO-oxidizing Euryarchaeota from hypersaline cinders, sediments and soils, and description of a novel CO oxidizer, Haloferax namakaokahaiae Mke2.3T, sp. nov.FEMS Microbiol Ecol. 92(4).
  10. ↑ Sánchez-Nieves R, Facciotti MT, Saavedra-Collado S, Dávila-Santiago L, Rodríguez-Carrero R, Montalvo-Rodríguez R. (2016) Draft genome sequence of Halorubrum tropicale strain V5, a novel halophilic archaeon isolated from the solar salterns of Cabo Rojo, Puerto Rico. Genom Data. 6;7:284-286.
  11. ↑ Sánchez-Nieves R, Facciotti MT, Saavedra-Collado S, Dávila-Santiago L, Rodríguez-Carrero R, Montalvo-Rodríguez R. (2016) Draft genome of Haloarcula rubripromontorii strain SL3, a novel halophilic archaeon isolated from the solar salterns of Cabo Rojo, Puerto Rico. Genom Data. 6;7:287-289.
  12. ↑ Jaakkola ST, Pfeiffer F, Ravantti JJ, Guo Q, Liu Y, Chen X, Ma H, Yang C, Oksanen HM, Bamford DH.(2016) The complete genome of a viable archaeum isolated from 123-million-year-old rock salt. Environ Microbiol. 18(2):565-579.
  13. ↑ Gupta, R.S., Naushad, S., Baker, S. (2015) CPhylogenomic analyses and molecular signatures for the class Halobacteria and its two major clades: a proposal for division of the class Halobacteria into an emended order Halobacteriales and two new orders, Haloferacales ord. nov. and Natrialbales ord. nov., containing the novel families Haloferacaceae fam. nov. and Natrialbaceae fam. nov.." Int J Syst Evol Microbiol. 65: 1050-1069
  14. ↑ Gupta RS, Naushad S, Fabros R, Adeolu M. (2016) "A phylogenomic reappraisal of family-level divisions within the class Halobacteria: proposal to divide the order Halobacteriales into the families Halobacteriaceae, Haloarculaceae fam. nov., and Halococcaceae fam. nov., and the order Haloferacales into the families, Haloferacaceae and Halorubraceae fam nov." Antonie Van Leeuwenhoek. 2016 Feb 2. [Epub ahead of print]
  15. ↑ Yadav, Ajar Nath; Sharma, Divya; Gulati, Sneha; Singh, Surender; Dey, Rinku; Pal, Kamal Krishna; Kaushik, Rajeev; Saxena, Anil Kumar (2015-07-28). "Haloarchaea Endowed with Phosphorus Solubilization Attribute Implicated in Phosphorus Cycle". Scientific Reports. 5. Bibcode:2015NatSR...512293Y. doi:10.1038/srep12293. ISSN 2045-2322. PMC 4516986. PMID 26216440.
  16. ↑ DasSarma, Shiladitya (2007). "Extreme Microbes". American Scientist. 95 (3): 224–231. doi:10.1511/2007.65.1024. ISSN 0003-0996.
  17. ↑ Stevenson, Andrew; Cray, Jonathan A; Williams, Jim P; Santos, Ricardo; Sahay, Richa; Neuenkirchen, Nils; McClure, Colin D; Grant, Irene R; Houghton, Jonathan DR; Quinn, John P; Timson, David J; Patil, Satish V; Singhal, Rekha S; Antón, Josefa; Dijksterhuis, Jan; Hocking, Ailsa D; Lievens, Bart; Rangel, Drauzio E N; Voytek, Mary A; Gunde-Cimerman, Nina; Oren, Aharon; Timmis, Kenneth N; McGenity, Terry J; Hallsworth, John E (June 2015). "Is there a common water-activity limit for the three domains of life?". The ISME Journal. pp. 1333–1351. doi:10.1038/ismej.2014.219. PMC 4438321. Missing or empty |url= (help)
  18. ↑ Cheftel, J. Claude (1 August 1995). "Review : High-pressure, microbial inactivation and food preservation". Food Science and Technology International. pp. 75–90. doi:10.1177/108201329500100203.
  19. ↑ Costa, M. S. da; Santos, H.; Galinski, E. A. (1998). "An overview of the role and diversity of compatible solutes in Bacteria and Archaea". Biotechnology of Extremophiles. Springer, Berlin, Heidelberg. pp. 117–153. doi:10.1007/bfb0102291.
  20. ↑ Williams, Timothy; Allen, Michelle; Tschitschko, Bernhard; Cavicchioli, Ricardo. "Glycerol metabolism of haloarchaea". doi:10.1111/1462-2920.13580/full.
  21. ↑ Soppa, J.; Baumann, A.; Brenneis, M.; Dambeck, M; Hering, O.; Lange, C. "Genomics and functional genomics with haloarchaea".
  22. ↑ Williams, Timothy; Allen, Michelle; Tschitschko, Bernhard; Cavicchioli, Ricardo. "Glycerol metabolism of haloarchaea". doi:10.1111/1462-2920.13580/full.
  23. ↑ Williams, Timothy; Allen, Michelle; Tschitschko, Bernhard; Cavicchioli, Ricardo. "Glycerol metabolism of haloarchaea". doi:10.1111/1462-2920.13580/full.
  24. ↑ DasSarma, Shiladitya. "Extreme Halophiles Are Models for Astrobiology" (PDF). Archived from the original (PDF) on 2007-02-02. Retrieved 2007-03-17.

Further reading

Scientific journals

  • Soppa J (March 2006). "From genomes to function: haloarchaea as model organisms". Microbiology. 152 (Pt 3): 585–90. doi:10.1099/mic.0.28504-0. PMID 16514139.
  • Cavalier-Smith, T (2002). "The neomuran origin of archaebacteria, the negibacterial root of the universal tree and bacterial megaclassification". Int. J. Syst. Evol. Microbiol. 52 (Pt 1): 7&ndash, 76. doi:10.1099/00207713-52-1-7. PMID 11837318.
  • Woese, CR; Kandler O; Wheelis ML (1990). "Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya". Proc. Natl. Acad. Sci. USA. 87 (12): 4576&ndash, 4579. Bibcode:1990PNAS...87.4576W. doi:10.1073/pnas.87.12.4576. PMC 54159. PMID 2112744.
  • Cavalier-Smith, T (1986). "The kingdoms of organisms". Nature. 324 (6096): 416&ndash, 417. Bibcode:1986Natur.324..416C. doi:10.1038/324416a0. PMID 2431320.

Scientific books

  • Grant WD, Kamekura M, McGenity TJ, Ventosa A (2001). "Class III. Halobacteria class. nov.". In DR Boone, RW Castenholz. Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer Verlag. p. 169. ISBN 978-0-387-98771-2.
  • Garrity GM, Holt JG (2001). "Phylum AII. Euryarchaeota phy. nov.". In DR Boone, RW Castenholz. Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer Verlag. p. 169. ISBN 978-0-387-98771-2.

Scientific databases

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.