Halobacteria

Note: The word "halobacteria" is also the plural form of the word "halobacterium". Halobacteria are now recognized as archaea, rather than bacteria. The name 'halobacteria' was assigned to this group of organisms before the existence of the domain Archaea was realised, and remains valid according to taxonomic rules. In a non-taxonomic context, halophilic archaea are also sometimes referred to as haloarchaea to distinguish them from halophilic bacteria.

In taxonomy, the Halobacteria (also Halomebacteria) are a class of the Euryarchaeota,^[1] found in water saturated or nearly saturated with salt. They are also called halophiles, though this name is also used for other organisms which live in somewhat less concentrated salt water. They are common in most environments where large amounts of salt, moisture, and organic material are available.

Halobacteria can grow aerobically or anaerobically. Parts of the membranes of halobacteria are purplish in color, and large blooms of Halobacteria appear reddish, from the pigment bacteriorhodopsin, related to the retinal pigment rhodopsin. This pigment is used to absorb light, which provides energy to create ATP. Halobacteria also possess a second pigment, 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 halobacteria are incapable of fixing carbon from carbon dioxide.^[2]

Taxonomy

The extremely halophilic, aerobic members of Archaea are classified within the family Halobacteriaceae, order Halobacteriales in Class III. Halomebacteria of the phylum Euryarchaeota (International Committee on Systematics of Prokaryotes, Subcommittee on the taxonomy of Halobacteriaceae. Currently (September, 2010), the family Halobacteriaceae comprises 29 genera.

Domain : Archaea

Phylum: Euryarchaeota

• Class: Halomebacteria
  • Order: Halobacteriales
    • Family: Halobacteriaceae
      • Haladaptatus [Hap.]
        • Haladaptatus cibarius
        • Haladaptatus litoreus
        • Haladaptatus paucihalophilus (Type species)
      • Halalkalicoccus [Hac.]
        • Halalkalicoccus jeotgali
        • Halalkalicoccus tibetensis (Type species)
      • "Halarchaeum" [Hla.]
        • "Halarchaeum acidiphilum" (Type species) (IJSEM in press)
      • Haloarcula [Har.]
        • Haloarcula amylolytica
        • Haloarcula argentinensis
        • Haloarcula hispanica
        • Haloarcula japonica
        • Haloarcula marismortui
        • Haloarcula quadrata
        • "Haloarcula salaria" (IJSEM in press)
        • "Haloarcula tradensis" (IJSEM in press)
        • Haloarcula vallismortis (Type species)
      • Halobacterium [Hbt.] (Type genus)
        • Halobacterium jilantaiense
        • Halobacterium noricense
        • Halobacterium piscisalsi
        • Halobacterium salinarum (Type species)
      • Halobaculum [Hbl.]
        • Halobaculum gomorrense (Type species)
      • Halobiforma [Hbf.]
        • Halobiforma haloterrestris (Type species)
        • Halobiforma lacisalsi
        • Halobiforma nitratireducens
      • Halococcus [Hcc.]
        • Halococcus dombrowskii
        • Halococcus hamelinensis
        • Halococcus morrhuae (Type species)
        • Halococcus qingdaonensis
        • Halococcus saccharolyticus
        • Halococcus salifodinae
        • Halococcus thailandensis
      • Haloferax [Hfx.]
        • Haloferax alexandrinus
        • 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 rufum" (IJSEM in press)
      • Halogranum [Hgn.]
        • "Halogranum amylolyticum" (IJSEM in press)
        • "Halogranum gelatinilyticum" (IJSEM in press)
        • Halogranum rubrum (Type species)
      • "Halolamina" [Hlm.]
        • "Halolamina pelagica" (Type species) (IJSEM in press)
      • "Halomarina" [Hmr.]
        • "Halomarina oriensis" (Type species) (IJSEM in press)
      • Halomicrobium [Hmc.]
        • Halomicrobium katesii
        • Halomicrobium mukohataei (Type species)
      • "Halonotius" [Hns.]
        • "Halonotius pteroides" (Type species)
      • Halopelagius [Hpl.]
        • Halopelagius inordinatus (Type species)
      • Halopiger [Hpg.]
        • Halopiger aswanensis
        • Halopiger xanaduensis (Type species)
      • Haloplanus [Hpn.]
        • "Haloplanus aerogenes" (Type species) (IJSEM in press)
        • Haloplanus natans (Type species)
        • Haloplanus vescus
      • Haloquadratum [Hqr.]
        • Haloquadratum walsbyi (Type species)
      • Halorhabdus [Hrd.]
        • Halorhabdus tiamatea
        • Halorhabdus utahensis (Type species)
      • Halorubrum [Hrr.]
        • Halorubrum aidingense
        • Halorubrum alkaliphilum
        • "Halorubrum aquaticum" (IJSEM in press)
        • Halorubrum arcis
        • Halorubrum californiense
        • Halorubrum chaoviator
        • Halorubrum cibi
        • Halorubrum coriense
        • Halorubrum distributum
        • Halorubrum ejinorense
        • Halorubrum ezzemoulense
        • Halorubrum kocurii
        • Halorubrum lacusprofundi
        • Halorubrum lipolyticum
        • Halorubrum litoreum
        • Halorubrum luteum
        • Halorubrum orientale
        • Halorubrum saccharovorum (Type species)
        • Halorubrum sodomense
        • Halorubrum tebenquichense
        • Halorubrum terrestre
        • Halorubrum tibetense
        • Halorubrum trapanicum
        • Halorubrum vacuolatum
        • Halorubrum xinjiangense
      • "Halorussus" [Hrs.]
        • "Halorussus rarus" (Type species) (Extremophiles [Epub ahead of print])
      • Halosarcina [Hsn.]
        • "Halosarcina limi" (IJSEM in press)
        • Halosarcina pallida (Type species)
      • Halosimplex [Hsx.]
        • Halosimplex carlsbadense (Type species)
      • Halostagnicola [Hst.]
        • "Halostagnicola alkaliphila" (IJSEM in press)
        • "Halostagnicola kamekurae" (IJSEM in press)
        • Halostagnicola larsenii (Type species)
      • Haloterrigena [Htg.]
        • "Haloterrigena daqingensis" (IJSEM in press)
        • Haloterrigena hispanica
        • Haloterrigena jeotgali
        • Haloterrigena limicola
        • Haloterrigena longa
        • Haloterrigena saccharevitans
        • Haloterrigena salina
        • Haloterrigena thermotolerans
        • Haloterrigena turkmenica (Type species)
      • Halovivax [Hvx.]
        • Halovivax asiaticus (Type species)
        • Halovivax ruber
      • Natrialba [Nab.]
        • Natrialba aegyptia
        • Natrialba asiatica (Type species)
        • Natrialba chahannaoensis
        • Natrialba hulunbeirensis
        • Natrialba magadii
        • Natrialba taiwanensis
      • Natrinema [Nnm.]
        • Natrinema altunense
        • Natrinema ejinorense
        • Natrinema gari
        • Natrinema pallidum
        • Natrinema pellirubrum (Type species)
        • Natrinema versiforme
      • "Natronoarchaeum" [Nac.]
        • "Natronoarchaeum mannanilyticum" (Type species) (IJSEM in press)
      • Natronobacterium [Nbt.]
        • Natronobacterium gregoryi (Type species)
      • Natronococcus [Ncc.]
        • Natronococcus amylolyticus
        • Natronococcus jeotgali
        • Natronococcus occultus (Type species)
      • Natronolimnobius [Nln.]
        • Natronolimnobius baerhuensis (Type species)
        • Natronolimnobius innermongolicus
      • Natronomonas [Nmn.]
        • "Natronomonas moolapensis"
        • Natronomonas pharaonis (Type species)
      • Natronorubrum [Nrr.]
        • Natronorubrum aibiense
        • Natronorubrum bangense (Type species)
        • Natronorubrum sediminis
        • Natronorubrum sulfidifaciens
        • Natronorubrum tibetense
      • "Salarchaeum" 属 [Sar.]
        • "Salarchaeum japonicum" (Type species) (IJSEM in press)

References

Further reading

Scientific journals

• 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): 7–76. 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): 4576–4579. Bibcode 1990PNAS...87.4576W. doi:10.1073/pnas.87.12.4576. PMC 54159. PMID 2112744. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=54159. 
• Cavalier-Smith, T (1986). "The kingdoms of organisms". Nature 324 (6096): 416–417. 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 and RW Castenholz, eds.. Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer Verlag. pp. 169. ISBN 978-0387987712. 
• Garrity GM, Holt JG (2001). "Phylum AII. Euryarchaeota phy. nov.". In DR Boone and RW Castenholz, eds.. Bergey's Manual of Systematic Bacteriology Volume 1: The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer Verlag. pp. 169. ISBN 978-0387987712. 

Scientific databases

• PubMed references for Halobacteria
• PubMed Central references for Halobacteria
• Google Scholar references for Halobacteria

External links

• NCBI taxonomy page for Halobacteria
• Search Tree of Life taxonomy pages for Halobacteria
• Search Species2000 page for Halobacteria
• MicrobeWiki page for Halobacteria
• LSPN page for Halobacteria