Haloferax volcanii
A Microbial Biorealm page on the genus Haloferax volcanii
Classification
Higher Order Taxa
Domain: Archaea
Phylum: Euryarchaeota
Class: Halobacteria
Order: Halobacteriales
Family: Halobacteriaceae
Genus: Haloferax
Species
Taxonomy of Haloferax volcanii
Description and significance
Haloferax volcanii (formerly Halobacterium volcanii) was first identified in the 1930s by microbiologist Benjamin Elazari Volcani, for whom the species is named [1]. It is a moderate halophile and a mesophile, and can be found living in the waters of the Dead Sea, a salt lake in Israel. The saline water of the Dead Sea contains a high concentration of sodium, magnesium, and calcium salts, and is very slightly acidic; correspodingly, these conditions are idea for growth of H. volcanii. Members of H. volcanii are pleotropic, and may appear in a variety of shapes, including disk-like and cup-like forms [2]. Like many halophiles, it maintains a high concentration of carotenoid pigments in its cell membrane, giving colonies of H. volcanii a reddish color [3].
H. volcanii is a chemoorganotroph, preferentially metabolizing sugars as a carbon source [3]. It is primarily aerobic, but is capable of anaerobic respiration under certain conditions [4].
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Genome structure
The genome of the DS2 strain of H. volcanii has been completely sequenced. The genome consists of one large circular chromosome approximately 2.85 Mb in length; three smaller circular chromosomes ranging in size between 85 kb and 636 kb; and a single plasmid of approximately 6.4 kb. In total, the complete genome length is approximately 4.01 Mb.
The base pairing frequency in the genome of H. volcanii is heavily skewed in favor of GC pairing, comprising 65% of all base pairs. Atypically, the main chromosome possesses 2 origins of replication, a trait which is rare in archaea and almost nonexistent in bacteria.
H. volcanii microbes are capable of plasmid exchange via conjugation. In 1984, the species was the first archeon ever to be observed undergoing genetic transfer [6].
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Cell structure, metabolism & life cycle
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Ecology (including pathogenesis)
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Interesting feature
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