halobacterium

Halobacterium
Halobacterium sp. strain NRC-1, each cell about 5 μm in length.
Scientific classification
Domain: Archaea Kingdom: Euryarchaeota Phylum: Euryarchaeota Class: Halobacteria Order: Halobacteriales Family: Halobacteriaceae Genus: Halobacterium
Binomial name
Halobacterium Elazari-Volcani 1957
Species
H. jilantaiense H. noricense H. salinarum H. piscisalsi
Synonyms
Flavobacterium (subgen. Halobacterium) Elazari-Volcani 1940 Halobacter Anderson 1954 Halobacter not "Halobacterium" Schoop 1935 (nomen nudum)

Note: The word "halobacterium" is also the singular form of the word "halobacteria".

In taxonomy, Halobacterium is a genus of the Halobacteriaceae.^[1]

The genus Halobacterium ("Salt" or "Ocean Bacterium") consists of several species of archaea with an aerobic metabolism which require an environment with a high concentration of salt; many of their proteins will not function in low-salt environments. They grow on amino acids in their aerobic conditions. Their cell walls are also quite different from those of bacteria, as ordinary lipoprotein membranes fail in high salt concentrations. In shape, they may be either rods or cocci, and in color, either red or purple. They reproduce using binary fission (by constriction), and are motile. Halobacterium grows best in a 42 degree Celsius environment. The genome of an unspecified Halobacterium species has been sequenced and comprises 2,571,010 bp (base pairs) of DNA compiled into three circular strands: one large chromosome with 2,014,239 bp, and two smaller ones with 191,346 and 365,425 bp. This species, called Halobacterium sp. NRC-1, has been extensively used for post-genomic analysis. Halobacterium species can be found in the Great Salt Lake, the Dead Sea, Lake Magadi, and any other waters with high salt concentration. Purple Halobacterium species owe their color to bacteriorhodopsin, a light-sensitive protein which provides chemical energy for the cell by using sunlight to pump protons out of the cell. The resulting proton gradient across the cell membrane is used to drive the synthesis of the energy carrier ATP. Thus, when these protons flow back in, they are used in the synthesis of ATP (this proton flow can be emulated with an increase in pH outside of the cell, causing a flow of H⁺ ions). The bacteriorhodopsin protein is chemically very similar to the light-detecting pigment rhodopsin, found in the vertebrate retina.

Genera of Halobacterium

• "Halobacterium cutirubrum" > Halobacterium salinarum
• "Halobacterium denitrificans > Haloferax denitrificans
• "Halobacterium distributum" > Halorubrum distributum
• "Halobacterium halobium" > Halobacterium salinarum
• Halobacterium jilantaiense
• "Halobacterium lacusprofundi" > Halorubrum lacusprofundi
• "Halobacterium mediterranei" > Haloferax mediterranei
• Halobacterium noricense
• "Halobacterium pharaonis" > Natronomonas pharaonis
• Halobacterium piscisalsi
• "Halobacterium saccharovorum" > Halorubrum saccharovoru
• Halobacterium salinarum
• "Halobacterium sodomense" > Halorubrum sodomense
• "Halobacterium trapanicum" > Halorubrum trapanicum
• "Halobacterium vallismortis" > Haloarcula vallismortis
• "Halobacterium volcanii" > Halobacterium volcanii

References

Further reading

Scientific journals

• DasSarma, S., B.R. Berquist, J.A. Coker, P. DasSarma, J.A. Müller. 2006. Post-genomics of the model haloarchaeon Halobacterium sp. NRC-1. Saline Systems 2:3.

• Judicial, Commission of the International Committee on Systematics of Prokaryotes: (2005). "The nomenclatural types of the orders Acholeplasmatales, Halanaerobiales, Halobacteriales, Methanobacteriales, Methanococcales, Methanomicrobiales, Planctomycetales, Prochlorales, Sulfolobales, Thermococcales, Thermoproteales and Verrucomicrobiales are the genera Acholeplasma, Halanaerobium, Halobacterium, Methanobacterium, Methanococcus, Methanomicrobium, Planctomyces, Prochloron, Sulfolobus, Thermococcus, Thermoproteus and Verrucomicrobium, respectively. Opinion 79". Int. J. Syst. Evol. Microbiol. 55: 517–518. PMID 15653928. 

• Oren A, Ventosa A (2000). "International Committee on Systematic Bacteriology Subcommittee on the taxonomy of Halobacteriaceae. Minutes of the meetings, 16 August 1999, Sydney, Australia". Int. J. Syst. Evol. Microbiol. 50: 1405–1407. PMID 10843089. 

Scientific books

• DasSarma, S. 2004. Genome sequence of an extremely halophilic archaeon, in Microbial Genomes, pp. 383–399, C.M. Fraser, T. Read, and K.E. Nelson (eds.), Humana Press, Inc, Totowa, NJ.

• Lynn Margulis, Karlene V.Schwartz, Five Kingdoms. An Illustrated Guide to the Phyla of Life on Earth (W.H.Freeman, San Francisco, 1982) pp. 36–37

• Gibbons, NE (1974). "Family V. Halobacteriaceae fam. nov.". in RE Buchanan and NE Gibbons, eds.. Bergey's Manual of Determinative Bacteriology (8th ed.). Baltimore: The Williams & Wilkins Co.. 

• Elazari-Volcani, B (1957). "Genus XII. Halobacterium Elazari-Volcani, 1940". in RS Breed, EGD Murray, and NR Smith, eds.. Bergey's Manual of Determinative Bacteriology (7th ed.). Baltimore: The Williams & Wilkins Co.. pp. 207–212. 

• Elazari-Volcani, B (1940). Studies on the microflora of the Dead Sea. Doctoral dissertation, Hebrew University, Jerusalem. pp. pp. 1-116 and i-xiii. 

Scientific databases

• PubMed references for Halobacterium
• PubMed Central references for Halobacterium
• Google Scholar references for Halobacterium

External links

• NCBI taxonomy page for Halobacterium
• Search Tree of Life taxonomy pages for Halobacterium
• Search Species2000 page for Halobacterium
• MicrobeWiki page for Halobacterium
• LSPN page for Halobacterium
• The Halobacterium Genome

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