Nitrospinota is a bacterial phylum. Despite only few described species, members of this phylum are major nitrite-oxidizing bacteria in surface waters in oceans. By oxidation of nitrite to nitrate they are important in the process of

nitrification ''Nitrification'' is the biological oxidation of ammonia to nitrate via the intermediary nitrite. Nitrification is an important step in the nitrogen cycle in soil. The process of complete nitrification may occur through separate organisms or ent ...

in marine environments. Although the genus Nitrospina is an aerobic bacterium, it was shown to oxidize nitrite also in oxygen minimum zone of the ocean. Depletion of oxygen in such zones leads to preference of anaerobic processes such as

denitrification Denitrification is a microbially facilitated process where nitrate (NO3−) is reduced and ultimately produces molecular nitrogen (N2) through a series of intermediate gaseous nitrogen oxide products. Facultative anaerobic bacteria perform denitr ...

and nitrogen loss through

anammox Anammox, an abbreviation for "anaerobic ammonium oxidation", is a globally important microbial process of the nitrogen cycle that takes place in many natural environments. The bacteria mediating this process were identified in 1999, and were a gr ...

. Nitrospina thus outweigh nitrogen loss by

also in these oxygen depleted zones. Among the cultivated isolates within the genus ''Nitrospina'' are '' Nitrospina gracilis'' and '' Nitrospina watsonii''. Further genomes were resolved by culture-independent metagenome binning. The two ''Nitrospina'' species are, however, distantly related to environmentally abundant uncultured Nitrospinota. The two other strains were cultivated in 2020 each in the binary culture with

alphaproteobacteria ''Alphaproteobacteria'' or ''α-proteobacteria'', also called ''α-Purple bacteria'' in earlier literature, is a class of bacteria in the phylum '' Pseudomonadota'' (formerly "Proteobacteria"). The '' Magnetococcales'' and '' Mariprofundales'' ar ...

heterotroph A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

. They are called "''Candidatus'' Nitrohelix vancouverensis" and "''Candidatus'' Nitronauta litoralis". " Nitrohelix vancouverensis" is closely related to uncultivated environmentally abundant Nitrospinota clades 1 and 2.

Taxonomy

The currently accepted taxonomy is based on the

List of Prokaryotic names with Standing in Nomenclature List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclatu ...

(LPSN) and

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is lo ...

(NCBI). * Class Nitrospinia Lucker et al. 2022 ** Order Nitrospinales Lücker et al. 2022 *** Family Nitrospinaceae Garrity, Bell & Lilburn 2006 **** Genus "''Candidatus'' Nitrohelix" Mueller et al. 2021 ***** "''Ca.'' N. vancouverensis" Mueller et al. 2021 **** Genus "''Candidatus'' Nitromaritima" Ngugi et al. 2016 **** Genus "''Candidatus'' Nitronauta" Mueller et al. 2021 ***** "''Ca.'' N. litoralis" Mueller et al. 2021 **** Genus '' Nitrospina'' Watson & Waterbury 1971 ***** '' N. gracilis'' Watson & Waterbury 1971 ***** "'' N. watsonii''" Spieck et al. 2014

References

{{Taxonbar, from=Q26714852 Nitrogen cycle Bacteria phyla Bacteria

Taxonomy

See also

References