Halorhabdus utahensis
Classification
Archaea; Euryarchaeota; Halobacteria; Halobacteriales; Halobacteriaceae; Halorhabdus
Species
Halorhabdus utahensis
Description and Significance
Halorhabdus (salt-loving rod) utahensis (pertaining to the state of Utah) was isolated from a sediment sample that was collected in the southern arm of the hypersaline Great Salt Lake, Utah, USA. It is a motile, gram-negative, extreamly halophilic archaeon that forms red, circular colonies. It grows in 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. Halorhabdus utahensis has a high salinity optimum of 27% NaCl, which makes it one of the highest reported salinity optimum of any living organism
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, respectively, 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 do not stimulate the organism's growth include organic acids, amino acids, alcohols, glycogen, and starch.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
Cell Structure, Metabolism and Life Cycle
Halorhabdus utahensis is a pleomorphic organism that is usually in a rod shaped form, particularly in its younger years and later in life it become increasingly pleomorphic. Due to its pleomorphic nature it can appear as ellipsoids and spheres, ranging from 1-2X1 micro meters. The organisms are mobile and have a flagellum, ranging in size from 3 to 5 micro meters. The cells can be distinguished because of their gram-negative trait. Furthermore, Halorhabdus utahensis has a red color and the pigments are not precisely known but presumed to be, “carotenoids, probably bacterioruberins”. The outer cell layers are composed of proteinaceous.
Growth of the cell does not require amino acids, but does require nitrogen and a carbon source. The metabolism of Halorhabdus utahensis is aerobic, but is also a facilitative anaerobe. It receives its energy from carbohydrates where the carbon source is from fructose, xylose, and glucose. Not important to the growth of the cell, however a side product of it metabolism is the reduction of nitrate to nitrite. It has been found that it may grow anaerobically by fermentation of glucose.
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
References
1. Anderson, I., Tindall, B., Pomrenke, H., & Goker, M. (2009). Complete genome sequence of Halorhabdus utahensis type strain (AX-2T). Standards in Genomic Sciences, (1), 218-225.
2. Waino, M., Tindall, B., & Ingvorsen, K. (2000). Halorhabdus utahensis gen. nov., sp. nov., an aerobic, extremely halophilic member of the archaea from Great Salt Lake, Utah. International Journal of Systematic Evolutionary Microbiology, (50), 183-190.
3. Zhang, Tao, Supratim Datta, Jerry Eichler, and Natalia Ivanova. “Identification of a Haloalkaliphilic and Thermostable Cellulase with Improved Ionic Liquid Tolerance.” Green Chemistry 13 (2011): 2083-2090.
Author
Page authored by Elliot Swift, Mark Sherill, Matt Stoloff, Hannah Shumway, student of Prof. Jay Lennon at Michigan State University.
<-- Do not remove this line-->
