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 and lives in several places such as soil, sewage, freshwater, the walls of buildings and on the surface of monuments especially in polluted areas where the air contains high levels of nitrogen compounds.

Several studies are still being done with the bacterium, but will take some time due to the slow cell division rate and the high amounts of nitrogen needed to live.

Evidence suggests that ammonia-oxidizing bacteria (AOB) contribute significantly to the global production of nitrous oxide (produced by the reduction of nitrite).

[1] Nitrosomonas europaea is also capable of degrading benzene as well as a variety of halogenated organic compounds, including trichloroethylene and vinyl chloride.

Nitrosomonas europaea is also accountable for nitric acid production which can cause the dissolution of some stone and other construction materials found on statues and in buildings.