Halobacteriaceae

From Wikipedia, the free encyclopedia

Halobacteriaceae

Domain:	Archaea
Phylum:	Euryarchaeota
Class:	Halobacteria
Order:	Halobacteriales
Family:	Halobacteriaceae

Genus

Synonyms

Halobacteriaceae Gibbons 1974

In taxonomy, the Halobacteriaceae are a family of the Halobacteriales in the domain Archaea.^[1]

1 Overview
2 References
3 Further reading
4 External links

[edit] Overview

Halobacteriaceae are 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. Large blooms appear reddish, from the pigment bacteriorhodopsin. This pigment is used to absorb light, which provides energy to create ATP. Halobacteria also possess a second pigment, halorhodopsin, which pumps in chloride ions 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.

Halobacteria can exist in salty environments because although they are aerobes they have a separate and different way of creating energy through photosynthesis. Parts of the membranes of halobacteria are purplish in color. These parts conduct photosynthetic reactions with retinal pigment rather than chlorophyll. This allows them to create a proton gradient across the membrane of the cell which can be used to create ATP for their own use.

To live within there salty environments they have made certain adaptations. Their cellular machinery is adapted to high salt concentrations by having charged amino acids on their surfaces, allowing the cell to keep its water molecules around these components. They use the osmotic pressure and these amino acids to control the amount of salt within the cell. Also there are proteins inside of the cell that help to keep it alive in its environment. However, because of these adaptations if the cell were to be taken out of its natural salty environment it would most likely immediately burst from the osmotic pressure.

[edit] References

^ See the NCBI webpage on Halobacteriaceae. Data extracted from the NCBI taxonomy resources. National Center for Biotechnology Information. Retrieved on 2007-03-19.

[edit] Further reading

[edit] Scientific journals

Wright, A-DG (2006). "Phylogenetic relationships within the order Halobacteriales inferred from 16S rRNA gene sequences". Int. J. Syst. Evol. Microbiol. 56: 1223–1227. doi:10.1099/ijs.0.63776-0.

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.

Euzeby JP, Tindall BJ (2001). "Nomenclatural type of orders: corrections necessary according to Rules 15 and 21a of the Bacteriological Code (1990 Revision), and designation of appropriate nomenclatural types of classes and subclasses. Request for an Opinion". Int. J. Syst. Evol. Microbiol. 51: 725–727. PMID 11321122.

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.

[edit] Scientific books

Grant WD, Larsen H (1989). "Group III. Extremely halophilic archaeobacteria. Order Halobacteriales ord. nov.", in JT Staley, MP Bryant, N Pfennig, and JG Holt, eds.: Bergey's Manual of Systematic Bacteriology, Volume 3, 1st ed., Baltimore: The Williams & Wilkins Co., p. 169.

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..