Haloarcula Explained

Haloarcula (common abbreviation Har.) is a genus of extreme halophilic Archaea in the class of Halobactaria.

Cell Structure

Haloarcula species can be distinguished from other genera in the family Halobacteriaceae by the presence of specific derivatives of TGD-2 polar lipids. H. quadrata has predominantly flat, square-shaped, somewhat pleomorphic cells.^[1]

Metabolism

H. quadrata was first isolated when researchers were attempting to culture Haloquadratum walsbyi, a haloarchaeon that was thought to be unculturable until 2004. Similar to other halophilic archaea, Haloarcula species grow optimally at 40–45 °C. Growth appears in sheets of up to 65 cells often in the shape of a square or triangle.

Taxonomy

The genus of Haloarcula was long grouped with other halophilic archaea such as Halobacterium until genomic analysis prompted to reorder this genus in the new family of Haloarculaceae.

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)^[2] and National Center for Biotechnology Information (NCBI).^[3]

Ecology

Haloarcula species are found in neutral saline environments such as salt lakes, marine salterns, and saline soils. Like other members of the family Halobacteriaceae, Haloarcula requires at least 1.5 M NaCl for growth, but grow optimally in 2.0 to 4.5 M NaCl.

See also

• List of Archaea genera

Further reading

• Torreblanca M, Rodriquez-Valera F, Juez G, Ventosa A, Kamekura M, Kates M . 1986 . Classification of non-alkaliphilic halobacteria based on numerical taxonomy and polar lipid composition, and description of Haloarcula gen. nov. and Haloferax gen.nov . Syst. Appl. Microbiol. . 8 . 1–2 . 89 - 99 . 10.1016/s0723-2020(86)80155-2.
• 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 . 3 . 1405 - 1407 . 10843089 . 10.1099/00207713-50-3-1405. free .
• Javor B, Requadt C, Stoeckenius W . 1982 . Box-shaped halophilic bacteria . J. Bacteriol. . 151 . 1532 - 1542 . 6286602 . 3 . 10.1128/jb.151.3.1532-1542.1982 . 220435.

External links

• Haloarcula at BacDive - the Bacterial Diversity Metadatabase

Notes and References

1. Oren. A.. Ventosa. A.. Gutierrez. M. C.. Kamekura. M.. 1999. Haloarcula quadrata sp. nov., a square, motile archaeon isolated from a brine pool in Sinai (Egypt). International Journal of Systematic Bacteriology. 49. 3. 1149–1155. 10.1099/00207713-49-3-1149. 10425773. free.
2. Web site: J.P. Euzéby . Haloarcula . 2023-10-10 . List of Prokaryotic names with Standing in Nomenclature (LPSN).
3. Web site: Sayers . et al.. Haloarcula . 2023-10-10 . National Center for Biotechnology Information (NCBI) taxonomy database.
4. Web site: The LTP . 10 May 2023.
5. Web site: LTP_all tree in newick format. 10 May 2023.
6. Web site: LTP_06_2022 Release Notes. 10 May 2023.
7. Web site: GTDB release 08-RS214 . Genome Taxonomy Database. 10 May 2023.
8. Web site: ar53_r214.sp_label . Genome Taxonomy Database. 10 May 2023.
9. Web site: Taxon History . Genome Taxonomy Database. 10 May 2023.