Bacteria Genomes - NITROSOMONAS EUROPAEA

Nitrosomonas europaea is a Gram-negative obligate chemolithoautotroph that can derive all its energy and reductant for growth from the oxidation of ammonia to nitrite.

While not using photosynthesis for energy is not unique, "burning" ammonia with oxygen is. Both are characteristics of Nitrosomonas europaea. It lives in several places such as soil, sewage, freshwater, the walls of buildings and on the surface of monuments especially in polluted areas where air contains high levels of nitrogen compounds. This microbe prefers an optimum pH of 6.0-9.0, fairly neutral conditions, has an aerobic metabolism and prefers a temperature range of 20-30 degrees centigrade. Most are motile with flagella located in the polar regions although some species are nonmotile.

The reaction catalysed by these bacteria is the first step in the oxidation of ammonia to nitrate. Nitrosomonas europaea are also important in the treatment of industrial and sewage waste in the first step of oxidising ammonia to nitrate. Evidence suggests that ammonia-oxidising bacteria contribute significantly to the global production of nitrous oxide (produced by the reduction of nitrite). Nitrosomonas europaea also is capable of degrading a variety of halogenated organic compounds, including trichloroethylene, benzene, and vinyl chloride. The ability of nitrifying organisms to degrade some pollutants may make these organisms attractive for controlled bioremediation in nitrifying soils and waters.

Nitrosomonas europaea must consume large amounts of ammonia before it will divide, and cell division may take up to several days. It is also accountable for nitric acid production which can cause the dissolvence of some stone and other construction materials found on statues and in buildings.

References:

J. Bacteriol 185(9):2759-73, 2003
http://www.jgi.doe.gov/JGI_microbial/html/nitrosomonas/nitro_content.html