Editing Nitrification (section)

====Ammonia-Oxidizing Bacteria====
Ammonia-Oxidizing Bacteria (AOB) are typically Gram-negative bacteria and belong to [[Betaproteobacteria]] and [[Gammaproteobacteria]]<ref>{{cite journal | vauthors = Purkhold U, Pommerening-Röser A, Juretschko S, Schmid MC, Koops HP, Wagner M | title = Phylogeny of all recognized species of ammonia oxidizers based on comparative 16S rRNA and amoA sequence analysis: implications for molecular diversity surveys | journal = Applied and Environmental Microbiology | volume = 66 | issue = 12 | pages = 5368–82 | date = December 2000 | pmid = 11097916 | pmc = 92470 | doi = 10.1128/aem.66.12.5368-5382.2000 | bibcode = 2000ApEnM..66.5368P }}</ref> including the commonly studied genera ''[[Nitrosomonas]]'' and ''[[Nitrococcus]]''. They are known for their ability to utilize ammonia as an energy source and are prevalent in a wide range of environments, such as soils, aquatic systems, and wastewater treatment plants.

AOB possess enzymes called [[ammonia monooxygenase]]s (AMOs), which are responsible for catalyzing the conversion of ammonia to hydroxylamine (NH<sub>2</sub>OH), a crucial intermediate in the process of nitrification.<ref>{{Cite journal |last1=Wright |first1=Chloë L. |last2=Schatteman |first2=Arne |last3=Crombie |first3=Andrew T. |last4=Murrell |first4=J. Colin |last5=Lehtovirta-Morley |first5=Laura E. |date=2020-04-17 |title=Inhibition of Ammonia Monooxygenase from Ammonia-Oxidizing Archaea by Linear and Aromatic Alkynes |url=http://dx.doi.org/10.1128/aem.02388-19 |journal=Applied and Environmental Microbiology |volume=86 |issue=9 |pages=e02388-19 |doi=10.1128/aem.02388-19 |pmid=32086308 |issn=0099-2240|pmc=7170481 |bibcode=2020ApEnM..86E2388W }}</ref> This enzymatic activity is sensitive to environmental factors, such as pH, temperature, and oxygen availability.

AOB play a vital role in soil nitrification, making them key players in [[nutrient cycling]]. They contribute to the transformation of ammonia derived from organic matter decomposition or fertilizers into nitrite, which subsequently serves as a substrate for nitrite-oxidizing bacteria (NOB).