Despite only few described species, members of this phylum are major nitrite-oxidizing bacteria in surface waters in oceans.

[3] 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 and nitrogen loss through anammox.

"Nitrohelix vancouverensis" is closely related to uncultivated environmentally abundant Nitrospinota clades 1 and 2.

Nitronauta litoralis" N. gracilis "N. watsonii" The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) [12] and National Center for Biotechnology Information (NCBI)[13]