Domain Archaea; Phylum Euryarchaeota; Class Archaeoglobi; Order Archaeoglobales; Family Archaeoglobaceae [Others may be used. Use NCBI link to find]
Description and Significance
G. ahangari is an anaerobic, coccoid-shaped member of Archaea that ranges from 0.3-0.5 micrometers in diameter. As seen under phase contrast microscopy, the cells are usually found alone or in couples and all have a single flagellum that is used for movement (mainly tumbling motility). Transmission Electron Microscopy releaved that the cell membranes of G. ahangari are similar to other members of Archaea, possesing three layers- a cytoplasmic membrane, a periplasmic space and a layer on the outer surface.
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
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Cellular structures of G. ahangari are similar to other archaea. The only notable feature of this organism is its one monopolar flagellum that serves motility purposes.
Geoglobus ahangari can operate in an autotrophic sense by using hydrogen as an electron donor while reducing Fe(III) oxide. This process produces extracellular waste in the form of magnetite.
In contrast to autotrophy, G. ahangari also acts as a chemoorganotroph by oxidizing pyruvate, acetate, palmitate or stearate while reducing Fe(III). It also has the ability to oxidize long-chain fatty acids. Both long-chain fatty acids and compounds such as acetate represent byproducts and debris of many other organisms, which G. ahangari uses to drive its own chemical processes.
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
The biogeochemical significance of G. ahangari is related to it's ability to use hydrogen emitted from geothermal marine vents as an electron donor when coupled to iron reduction. This autotrophy with use of Fe(III) oxide results in the accumulation of magnetite.
[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.
[http://ijs.sgmjournals.org/cgi/reprint/52/3/719 K. Kashefi, J. M. Tor, D. E. Holmes, C. V. Gaw Van Praagh, A. L. Reysenbach, and D. R. Lovley Geoglobus ahangari gen. nov., sp. nov., a novel hyperthermophilic archaeon capable of oxidizing organic acids and growing autotrophically on hydrogen with Fe(III) serving as the sole electron acceptor Int J Syst Evol Microbiol, May 2002; 52: 719 - 728.]
Page authored by _____, student of Prof. Jay Lennon at Michigan State University.
<-- Do not remove this line-->