Editing Nitrification (section)

=== Nitrite oxidation ===
The second step of nitrification is the oxidation of nitrite into nitrate. This process is sometimes known as nitratation. Nitrite oxidation is conducted by nitrite-oxidizing bacteria ('''NOB''') from the taxa ''[[Nitrospirota]]'',<ref>{{cite journal | vauthors = Daims H, Nielsen JL, Nielsen PH, Schleifer KH, Wagner M | title = In situ characterization of ''Nitrospira''-like nitrite-oxidizing bacteria active in wastewater treatment plants | journal = Applied and Environmental Microbiology | volume = 67 | issue = 11 | pages = 5273–84 | date = November 2001 | pmid = 11679356 | pmc = 93301 | doi = 10.1128/AEM.67.11.5273-5284.2001 | bibcode = 2001ApEnM..67.5273D | url = }}</ref> ''[[Nitrospinota]]'',<ref name=":0">{{cite journal | vauthors = Beman JM, Leilei Shih J, Popp BN | title = Nitrite oxidation in the upper water column and oxygen minimum zone of the eastern tropical North Pacific Ocean | journal = The ISME Journal | volume = 7 | issue = 11 | pages = 2192–205 | date = November 2013 | pmid = 23804152 | pmc = 3806268 | doi = 10.1038/ismej.2013.96 | bibcode = 2013ISMEJ...7.2192B }}</ref> ''[[Pseudomonadota]]''<ref>{{cite journal | vauthors = Poly F, Wertz S, Brothier E, Degrange V | title = First exploration of Nitrobacter diversity in soils by a PCR cloning-sequencing approach targeting functional gene nxrA | journal = FEMS Microbiology Ecology | volume = 63 | issue = 1 | pages = 132–40 | date = January 2008 | pmid = 18031541 | doi = 10.1111/j.1574-6941.2007.00404.x | doi-access =  | bibcode = 2008FEMME..63..132P }}</ref> and ''[[Chloroflexota]]''.<ref>{{cite journal | vauthors = Spieck E, Spohn M, Wendt K, Bock E, Shively J, Frank J, Indenbirken D, Alawi M, Lücker S, Hüpeden J | display-authors = 6 | title = Extremophilic nitrite-oxidizing Chloroflexi from Yellowstone hot springs | journal = The ISME Journal | volume = 14 | issue = 2 | pages = 364–379 | date = February 2020 | pmid = 31624340 | pmc = 6976673 | doi = 10.1038/s41396-019-0530-9 | bibcode = 2020ISMEJ..14..364S }}</ref> NOB are typically present in soil, geothermal springs, freshwater and marine ecosystems.