Cenarchaeum

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A Microbial Biorealm page on the genus Cenarchaeum

Classification

Domain: Archaea; Phylum: Thaumarchaeota; Order: Cenarchaeales; Family: Cenarchaeaceae; Genus: Cenarchaeum

An important species is Cenarchaeum symbiosum.

Description and significance

Describe the disease caused by this organism if it is a pathogen, or the natural macroscopic "field guide" appearance and habitat of your organism if it is not. What is or has been the impact your organism on human history or our environment?. How does it do this? How have we harnessed this power, or tried to prevent it? In other words, how do you know it if you see it, and how does its presence influence humans in the present, and historically?

Genome structure

Cenarchaeum symbiosum has a single circular chromosome 2,045,086 bp in length. On average, the genome has 57.74% G/C content. The origin(s) of replication are not known. 2,017 protein-encoding genes were predicted and for 65% of these, homology searches showed functional or conserved roles.

In terms of metabolism, genetic analysis suggests that C. symbiosum uses at least an incomplete TCA cycle. The genome also indicates an intact Embden-Meyerhof-Parnas pathway, although without glucokinase or pyruvate kinase, which suggests that it may form glucose through this pathway rather than breaking it down. However, genes were also found to encode carbohydrate kinases of unknown specificity. Many Entner-Douodoroff pathway components were missing from the genome, indicating that this archaeum does not use the ED pathway for catabolism. However, a nonoxidative pentose phosphate pathway was identified, which could provide NADPH and ribose sugars for anabolism. Homologous genes that could be associated with ammonia oxidation occur in the genome of C. symbiosum, but between missing homologues and identified potential cytochrome replacements for mobile electron carrying suggest that energy derived from ammonia oxidiation is obtained through different mechanisms than those of most nitrifying bacteria.

This genome contains most of the core genes generally expected of Archaea. A eukaryal-like H3-H4 histone was also found in the genome of C. symbiosum, the first crenarchaeote in which this was found.

Cell structure, metabolism & life cycle

Provide a physical and biochemical description of the organism. What kind of organism is it, what does it look like, how is it built, what are its metabolic properties, how can it be identified, what is it's life cycle, &c. In other words, describe the organism from its perspective.

Ecology (including pathogenesis)

Describe its habitat, symbiosis, and contributions to environment. If it is a pathogen, how does this organism cause disease? Human, animal, plant hosts? Describe virulence factors and patient symptoms.

Interesting feature

Describe in detail one particularly interesting aspect of your organism or it's affect on humans or the environment.

References

Euzeby, J.P. "Classification of domains and phyla - Hierarchical classification of prokaryotes (bacteria)". List of Prokaryotic names with Standing in Nomenclature. Last major update October 06, 2011. Accessed October 19, 2011.

Hallam, S.J., K.T. Konstantinidis, N. Putnam, C. Schleper, Y. Watanabe, J. Sugahara, C. Preston,J. de la Torre, P.M. Richardson, and E.F. DeLong. "Genomic analysis of the uncultivated marine crenarchaeote Cenarchaeum symbiosum". Proceedings of the National Academy of Sciences of the United States of America. 2006. Volume 103. p. 18296-18301.

Preston, C.M., K.Y. Wu, T.F. Molinski, and E.F. DeLong. "A psychrophilic crenarchaeon inhabits a marine sponge: Cenarchaeum symbiosum gen. nov., sp. nov.". Proceedings of the National Academy of Sciences of the United States of America. 1996. Volume 93. p. 6241-6246