| Haloferax | |
|---|---|
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| SEM image of Haloferax mediterranei . | |
Scientific classification  | |
| Domain: | Archaea |
| Kingdom: | Euryarchaeota |
| Class: | Halobacteria |
| Order: | Haloferacales |
| Family: | Haloferacaceae |
| Genus: | Haloferax Torreblanca et al. 1986 [1] |
| Type species | |
| Haloferax volcanii (Mullakhanbhai & Larsen 1975) Torreblanca et al. 1986 | |
| Species | |
See text | |
Haloferax (common abbreviation: Hfx.) is a genus of halobacteria in the order Haloferacaceae. [2]
Cells of H. mediterranei and cells of the related species H. volcanii can undergo a process of genetic exchange between two cells which involves cell fusion resulting in a heterodiploid cell (containing two different chromosomes in one cell). [3] Although this genetic exchange ordinarily occurs between two cells of the same species, it can also occur at a lower frequency between an H. mediterranei and an H. volcani cell. These two species have an average nucleotide sequence identity of 86.6%. [3] During this exchange process, a diploid cell is formed that contains the full genetic repertoire of both parental cells, and genetic recombination is facilitated. Subsequently, the cells separate, giving rise to recombinant cells.
As of 2022, 13 species are validly published under the genus Haloferax. [1]
Several species and novel binomial names have been proposed, but not validly published.
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [1] and National Center for Biotechnology Information (NCBI). [2]
| 16S rRNA based LTP_06_2022 [10] [11] [12] | 53 marker proteins based GTDB 08-RS214 [13] [14] [15] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Halobacterium is a genus in the family Halobacteriaceae.
Halobacteriaceae is a family in the order Halobacteriales and the domain Archaea. Halobacteriaceae represent a large part of halophilic Archaea, along with members in two other methanogenic families, Methanosarcinaceae and Methanocalculaceae. The family consists of many diverse genera that can survive extreme environmental niches. Most commonly, Halobacteriaceae are found in hypersaline lakes and can even tolerate sites polluted by heavy metals. They include neutrophiles, acidophiles, alkaliphiles, and there have even been psychrotolerant species discovered. Some members have been known to live aerobically, as well as anaerobically, and they come in many different morphologies. These diverse morphologies include rods in genus Halobacterium, cocci in Halococcus, flattened discs or cups in Haloferax, and other shapes ranging from flattened triangles in Haloarcula to squares in Haloquadratum, and Natronorubrum. Most species of Halobacteriaceae are best known for their high salt tolerance and red-pink pigmented members, but there are also non-pigmented species and those that require moderate salt conditions. Some species of Halobacteriaceae have been shown to exhibit phosphorus solubilizing activities that contribute to phosphorus cycling in hypersaline environments. Techniques such as 16S rRNA analysis and DNA-DNA hybridization have been major contributors to taxonomic classification in Halobacteriaceae, partly due to the difficulty in culturing halophilic Archaea.
Halobacteriales are an order of the Halobacteria, 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.
Haloarchaea are a class of prokaryotic organisms under the archaeal phylum Euryarchaeota, 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 while valid according to taxonomic rules, should be updated. Halophilic archaea are generally referred to as haloarchaea to distinguish them from halophilic bacteria.
Halalkalicoccus is a genus of the Halobacteriaceae.
Haloarcula is a genus of extreme halophilic Archaea in the class of Halobactaria.
In taxonomy, Halogeometricum is a genus of the Haloferacaceae.
Haloterrigena is a genus of the Natrialbaceae.
In taxonomy, Halovivax is a genus of the Natrialbaceae. Some species of Halovivax are halophiles and have been found in Iran's Aran-Bidgol hypersaline lake.
In taxonomy, Natrialba is a genus of the Natrialbaceae. The genus consists of many diverse species that can survive extreme environmental niches, especially they are capable to live in the waters saturated or nearly saturated with salt (halophiles). They have certain adaptations to live within their salty environments. For example, 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. The osmotic pressure and these amino acids help to control the amount of salt within the cell.
In taxonomy, Natronobacterium is a genus of the Natrialbaceae. A member of the domain Archaea, it is both an extreme halophile and alkaliphile, thriving at an optimum saline concentration of 20% and optimum pH of 10.
Natronolimnobius is a genus of the Natrialbaceae.
Natronomonas is a genus of the Halobacteriaceae.
Haloferacaceae is a family of halophilic, chemoorganotrophic or heterotrophic archaea within the order Haloferacales. The type genus of this family is Haloferax. Its biochemical characteristics are the same as the order Haloferacales.
Natrialbales is an order of halophilic, chemoorganotrophic archaea within the class Haloarchaea. The type genus of this order is Natrialba.
Haloferacales is an order of halophilic, chemoorganotrophic or heterotrophic archaea within the class Haloarchaea. The type genus of this order is Haloferax.
Halorubraceae is a family of halophilic, chemoorganotrophic or heterotrophic archaea within the order Haloferacales. The type genus of this family is Halorubrum. Its biochemical characteristics are the same as the order Haloferacales.
Haloarculaceae is a family of halophilic and mostly chemoorganotrophic archaea within the order Halobacteriales. The type genus of this family is Haloarcula. Its biochemical characteristics are the same as the order Halobacteriales.
Haloarchaeobius is a genus of halophilic archaea in the family of Halobacteriaceae.
Halostella is a genus of halophilic archaea in the family of Halobacteriaceae.