Nitrogen
Nitrogen Uptake
- (15N-ρNO3-) uptake New Production
- 15N-ρNO3/chl a (N assimilation rate)
- (15N-ρNH4+) uptake Regenerated Production
- (15N-ρurea) uptake Regenerated Production
Nitrogen Assimilation
- [[Eukaryotic Assimilatory nitrate reductase, NAD(P)H dependent, Nitrate -> Nitrite, Nitrate (NR)]]
Nitrification
- DIN inventory with inhibitors
- Inhibitors with 14 or 13CO2 uptake
- Nitrite oxidation (Nxr)
- amoA gene or transcript abundance
- Natural abundance of N and O isotopes in nitrate, nitrite and ammonium
- 15N tracers
Denitrification
- acetylene-block proxy for denitrifcation enzyme activity
- 15N tracer-based method
- N2:Ar ratio quantification
- Mass Balance
- Stoichiometric approach
- Natural Abundances of 15N and 18O
Dissimilatory Nitrate Reduction to Ammonium
Anaerobic Ammonium Oxidation
- 15N tracers (15N labeled gases upon addition of 15NO3, 15NO2, or 15NH4)
- Functional gene quantification (hzs, hzo)
- FISH staining of anammox bacteria