Pyrodictium abyssi

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Archea (Domain); Crenarchaeota (Phylum); Thermoprotei (Class); Desulfurococcales (Order); Pyrodictiaceae (Family); Pyrodictium (Genus)


NCBI: Taxonomy

Pyrobacterium abyssi (Species)

Description and Significance

Pyrodictium abyssi is a gram negative, hyperthermophilic, anaerobic archaeum. This archaeum was first isolated in 1991 by Pley and Stetter. It was isolated from heat vents deep in the ocean called black smokers, which are formed as a result of volcanic activity deep beneath the ocean floor [X]. P. abyssi are capable of growing in temperatures ranging from 80-110oC but have maximum growth between 97-110oC and are capable of survival in an autoclave for up to an hour. Optimally, P. abyssi thrive at a pH of 5.5 but have been found to survive anywhere from 4.7-7.1. P. abyssi are capable of growing in NaCl concentrations ranging from .7-4.2% and are strictly anaerobic [X]. This archaeum is disc shaped and approximately .3-2.5µm in diameter and are .025-.05µm thick. P. abyssi grows in an extensive 3D network composed of cells and cannulae, which are hollow, extracellular tubules with a diameter of about 25nm. The cannulae bundle together to allow multiple cells to be connected [X]. This archaeum is a chemolithoautotroph and uses Hydrogen as an electron donor and Sulfur as an electron acceptor to perform inorganic redox reactions in extreme conditions. This archaeum could prove extremely useful in industrial biotechnology because it has been found to possess enzymes such as chaperone proteins and ATP synthase which are functional at high temperatures instead of denaturing [X].

Genome Structure

The genome has not yet been sequenced, but using relationships between various hyperthermophiles with respect to their size, their structural organization and their phylogenetic relationship based on the content of the respectetive 16rDNA genes it is determined the entire genome of pyrodictium abyssi is a single circular chromosome and approximately 1.6Mb. It is very similar to Hyperthermus butylicus (97% sequence coverage) and Pyrodictium occultum (96% sequence coverage), which is another sulfur reducing hyperthermophile belonging to the same genus both with BLAST E-values of 0.

Cell Structure, Metabolism and Life Cycle

Interesting features of cell structure; how it gains energy; what important molecules it produces.

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.


[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.


Page authored by _____, student of Prof. Jay Lennon at Michigan State University.

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