Halorhabdus

Halorhabdus
Scientific classification
Domain: Archaea
Kingdom: Euryarchaeota
Phylum: Euryarchaeota
Class: Halobacteria
Order: Halobacteriales
Family: Halobacteriaceae
Genus: Halorhabdus
Wainø et al. 2000 emend. Antunes et al. 2008
Species
  • H. tiamatea Antunes et al. 2008
  • H. utahensis Wainø et al. 2000 (type sp.)

In taxonomy, Halorhabdus is a genus of the Halobacteriaceae.

Description and significance

Halorhabdus utahensis (salt-loving rod) is a motile, Gram-negative, extremely halophilic archaeon that forms red, circular colonies. It grows at the temperatures between 17 and 55 °C, with optimal growth occurring at 50°C. It can also grow over a pH range of 5.5–8.5 with the optimal pH value between 6.7 and 7.1. Further, with its extremely high salinity optimum of 27% NaCl, Halorhabdus has one of the highest reported salinity optima of any living organism.

Genome structure

The genome of Halorhabdus was sequenced in August 2014.[1] The G + C content of its DNA is estimated to be 64%.

Cell structure and metabolism

The cells of H. utahensis are extremely pleomorphic, exhibiting any shape from irregular coccoid or ellipsoid to triangular, club-shaped or rod-shaped forms. The rod-shaped and ellipsoid cells are 2-10 by 0.5-1 µm and 1-2 by 1 µm in size, respectively, and the spherical cells have a diameter of approximately 1 µm. The archaeon uses only a limited range of substrates, such as glucose, xylose, and fructose, for growth, and is unique in its inability to utilize yeast extract or peptone. Other substances that did not stimulate the organism's growth include organic acids, amino acids, alcohols, glycogen, and starch.

Ecology

Strains of H. utahensis were isolated from samples from Great Salt Lake, Utah, USA.[2]

References

  1. ↑ Werner, J (Aug 2014). "Halorhabdus tiamatea: proteogenomics and glycosidase activity measurements identify the first cultivated euryarchaeon from a deep-sea anoxic brine lake as potential polysaccharide degrader.". Environmental Microbiol. 16 (8): 2525–37. doi:10.1111/1462-2920.12393.
  2. ↑ See the NCBI webpage on Halorhabdus. Data extracted from the "NCBI taxonomy resources". National Center for Biotechnology Information. Retrieved 2007-03-19.

Further reading

Scientific journals

Scientific books

Scientific databases


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