''Haloarcula'' (common abbreviation ''Har.'') is a genus of extreme halophilic

Archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...

in the class of Halobactaria.

Cell Structure

''Haloarcula'' species can be distinguished from other genera in the family

Halobacteriaceae In taxonomy, the Halobacteriaceae are a family of the Halobacteriales in the domain Archaea.See the NCBIbr>webpage on Halobacteriaceae Data extracted from the ''Halobacteriaceae'' represent a large part of halophilic Archaea, along with member ...

by the presence of specific derivatives of TGD-2 polar lipids. ''H. quadrata'' has predominantly flat, square-shaped, somewhat pleomorphic cells.

Metabolism

''H. quadrata'' was first isolated when researchers were attempting to culture ''

Haloquadratum walsbyi ''Haloquadratum walsbyi'' is of the genus ''Haloquadratum,'' within the archaea domain known for its square halophilic nature. First discovered in a brine pool in the Sinai peninsula of Egypt, ''H. walsbyi'' is noted for its flat, square-shaped ...

'', 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 ''Halobacterium'' (common abbreviation ''Hbt.'') is a genus in the family Halobacteriaceae. The genus ''Halobacterium'' ("salt" or "ocean bacterium") consists of several species of Archaea with an aerobic metabolism which requires an environment ...

'' until genomic analysis prompted to reorder this genus in the new family of

Haloarculaceae ''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. ...

Ecology

''Haloarcula'' species are found in neutral saline environments such as

salt lakes A salt lake or saline lake is a landlocked body of water that has a concentration of salt (chemistry), salts (typically sodium chloride) and other dissolved minerals significantly higher than most lakes (often defined as at least three grams of ...

, 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 the

NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The ...

br>webpage on Haloarcula
Data extracted from the

References

External links