| Halobacteriaceae | |
|---|---|
| Scientific classification | |
| Domain: | Archaea |
| Kingdom: | Euryarchaeota |
| Phylum: | Euryarchaeota |
| Class: | Halobacteria |
| Order: | Halobacteriales |
| Family: | Halobacteriaceae |
| Binomial name | |
| Halobacteriaceae Gibbons 1974 |
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| Genus | |
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In taxonomy, the Halobacteriaceae are a family of the Halobacteriales in the domain Archaea.[1]
Contents |
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 use of light energy. Parts of the membranes of halobacteria are purplish in color and containing retinal pigment. 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 their 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.