Natronomonas Pharaonis

A Microbial Biorealm page on the genus Natronomonas Pharaonis

Classification

Higher order taxa

Archaea; Euryarchaeota; Halobacteria; Halobacteriales; Halobacteriaceae; Natronomonas

Edited by Sarah Kwan of Rachel Larsen and Kit Pogliano

Species

Natronomonas Pharaonis

Edited by Sarah Kwan of Rachel Larsen and Kit Pogliano

Description and significance

Strains of Natronomonas pharaonis were first isolated in Egypt and Kenya from highly saline soda lakes with a pH of 11. N. pharaonis is an aerobic, haloalkaliphilic archaeon that grows optimally in 3.5 M NaCl and at a pH of 8.5, but it is sensitive to high magnesium concentrations. Genome analysis shows adaptation strategies of alkaliphiles in regards to its respiratory chain, nitrogen metabolism, and its cell envelope.

Edited by Sarah Kwan of Rachel Larsen and Kit Pogliano

Genome structure

The genome of N. pharaonis consists of three circular replicons, one 2.6-Mb chromosome and two plasmids (PL131 - 131kb, PL23 - 23kb). Its chromosome is GC-rich (63.4% GC) with an integrated copy of PL23. N. pharaonis also contains a high amount of acidic amino acids (average 19.3%) in its cytoplasmic proteins. This results in low isoelectric points (average pI 4.6), which is an adaptive feature of haloarchaea in order to survive in its hypersaline environment.

Edited by Sarah Kwan of Rachel Larsen and Kit Pogliano

Cell structure and metabolism

Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.

Natronomonas pharaonis has a high degree of nutritional self-sufficiency. It contains the correct enzymes for the biosynthesis of amino acids and coenzymes. However, because it lacks key enzymes of glycolytic pathways, N. pharaonis will most likely not be able to use sugar. The genome analysis shows that N. pharaonis supplies ammonia through three main mechanisms, allowing them to survive in extreme pH conditions, which reduce levels of ammonium ions.

Edited by Sarah Kwan of Rachel Larsen and Kit Pogliano

Ecology

Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.

Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Application to Biotechnology

Does this organism produce any useful compounds or enzymes? What are they and how are they used?

Current Research

Enter summaries of the most recent research here--at least three required

"Genome-wide proteomics of Natronomonas pharaonis" January 2007. A shotgun sequencing approach and SDS-PAGE was used to reach further conclusions about N. pharaonis's cellular physiology. A set of identified proteins consist of about 60% of the cytosolic proteins involved in metabolism and genetic information processing. Among the halophilic archaea, many of these proteins show a high genetic variablility.

"Large-Scale Identification of N-Terminal Peptides in the Halophilic Archaea Halobacterium salinarum and Natronomonas pharaonis" April 2007. A combined fractional diagonal chromatography (COFRADIC) and a strong cation exchange chromatography (SCX)were two methods used to characterize the proteins of N-terminal peptides. This data allowed for the correct assignment of start codons as well as showing that 60% of proteins undergo methionine cleavage, instead of 13-18%.

Edited by Sarah Kwan of Rachel Larsen and Kit Pogliano

References

Falb, M., Pfeiffer, F., Palm, P., Rodewald, K., Hickmann, V., Tittor, J., and Oesterhelt, D. "Living with two extremes: Conclusions from the genome sequence of Natronomonas pharaonis." Genome Research. 2005. 15. p. 1336-1343. (http://www.genome.org/cgi/reprint/15/10/1336)

Oesterhelt, D. "Natronomonas pharaonis - overview." Max Planck Institute of Biochemistry. 2007. (http://www.biochem.mpg.de/en/research/rd/oesterhelt/web_page_list/Org_Napha/index.html)

Edited by student of Rachel Larsen and Kit Pogliano