Sources may include:
- ammonium
- nitrate
- nitrite
- molecular nitrogen
- amino acids
- proteins
- host-derived nitrogen compounds
Operational definition
Matter-assimilation process.
The uptake and conversion of a nitrogen source into cellular nitrogen compounds.
The assimilated nitrogen ultimately enters:
- amino acids;
- proteins;
- nucleotides;
- cofactors;
- other nitrogen-containing biomass.
Nitrogen fixation is one possible upstream source-conversion process, but nitrogen assimilation also occurs from ammonium, nitrate, amino acids, and other compounds.