[13] All species included in this genus have ellipsoidal or rod-shaped cells which have extensive intracytoplasmic membranes displaying as flattened vesicles.
[11] Among the various species of Nitrosomonas that are known today, the complete genomes of N. ureae strain Nm10 and N. europaea, N.sp.
,[17] a highly reactive radical intermediate that can be partitioned into both of the main AOB products:
, a form of nitrogen more bioavailable for crops, but that conversely washes away from fields faster.
[15] These genes are present in different copies in various species; for instance, in Nitrosomonas sp.
While in N. europaea, N. eutropha, and N. cryotolerans, nirK is included in a multigenetic cluster;[20] in Nitrosomonas sp.
[22] The second gene involved in denitrification is norCBQD which encodes a nitric-oxide reductase that catalyze the reduction from
[15] Recently, it was found that the norSY gene encodes for a nitric-oxide reductase with copper in N. communis strain Nm2 and Nitrosomonas AL212.
Other species present different copies of this operon that encodes only for the IA form.
[15] In N. europaea, an operon is characterized by five genes (ccbL, ccbS, ccbQ, ccbO, and ccbN) that encode for the RuBisCO enzyme.
ccbQ and ccbO genes encode for a number of proteins involved in the mechanisms of processing, folding, assembling, activation, and regulation of the RuBisCO enzyme.
[26] Since Nitrosomonas are part of the ammonia-oxidizing bacteria (AOB), ammonia carriers are important to them.
Bacteria adapted to high concentrations of ammonia can absorb it passively by simple diffusion.
[27] Bacteria adapted to low concentrations of ammonia have a transporter (transmembrane protein) for this substrate.
This process occurs with the accompanying reduction of an oxygen molecule to water (which requires four electrons), and the release of energy.
[32] Two of the four electrons released by the reaction, return to the AMO to convert the ammonia in hydroxylamine.
[30] The species N. europaea has been identified as being able to degrade a variety of halogenated compounds including trichloroethylene, benzene, and vinyl chloride.
[33] Nitrosomonas is generally found in highest numbers in all habitats in which there is abundance of ammonia (environment with plentiful protein decomposition or in wastewater treatment), thrive in a pH range of 6.0–9.0, and a temperature range of 20–30 °C (68–86 °F).
[12] It is usually found in all types of waters, globally distributed in both eutrophic and oligotrophic freshwater and saltwater, emerging especially in shallow coastal sediments and under the upwelling zones, such as the Peruvian coast and the Arabian Sea,[34][35] but can also be found in fertilized soils.
[21] Some Nitrosomonas species, such as N.europaea, possess the enzyme urease (which catalyzes the conversion of urea into ammonia and carbon dioxide) and have been shown to assimilate the carbon dioxide released by the reaction to make biomass via the Calvin cycle, and harvest energy by oxidizing ammonia (the other product of urease) to nitrite.
This feature may explain enhanced growth of AOB in the presence of urea in acidic environments.
[36] In agriculture, nitrification made by Nitrosomonas represents a problem because the oxidized nitrite by ammonia can persist in the soil, leaching and making it less available for plants.
Nitrogen, if present in high quantities can cause algal development, leading to eutrophication with degradation of oceans and lakes.
[39] Nitrosomonas has also a role in biofilter systems, typically in association and collaboration with other microbes, to consume compounds such as
In this context, it may give aesthetic benefits in terms of reducing the appearance of wrinkles.
[40] The effectiveness of probiotic products has been studied to explore why N. eutropha, which is a highly mobile bacterium, has become extinct from the normal flora of our skin.
It has been studied in connection with the idea of having benefits through the repopulation and reintroduction of N. eutropha to the normal flora of human skin.