Comammox

Nitrification is the term describing the conversion of ammonia into nitrite and then into nitrate. This process is commonly carried out by two separate groups of microorganisms. However, complete conversion of ammonia into nitrate by a single microorganism was predicted in 2006 and this hypothetical organism was tentatively named "Comammox" (COMplete AMMonia OXidiser). Almost ten years later the presence of such organisms was discovered within the nitrospira and the nitrogen cycle had to be updated. The genomes revealed the presence of genes necessary for ammonia oxidation (e.g. amoA gene and hao cluster).