Halorhabdus
From MicrobeWiki, the student-edited microbiology resource
A Microbial Biorealm page on the genus Halorhabdus
Contents |
Classification
Higher order taxa
Archaea; Euryarchaeota; Halobacteria; Halobacteriales; Halobacteriaceae
Species
Halorhabdus utahensis
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NCBI: Taxonomy Genome |
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 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 optimum of any living organism.
Genome structure
The genome of Halorhabdus is yet to be sequenced. The G + C content of its DNA is estimated to be 64%.
Cell structure and metabolism
The cells of Halorhabdus utahensis are extremely pleomorphic, exhibiting anything from irregular coccoid or ellipsoid to triangular, club-shaped or rod-shaped forms. The rod-shaped and ellipsoid cells are 2-10 * 0.5-1 µm and 1-2 * 1 µm in size, respectivelly, and the spherical cells have a diameter of approximately 1 µm. The archaeon utilizes 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
The strains of Halorhabdus utahensis were isolated from samples from Great Salt Lake, Utah, USA.
