TABLE 2.
Nitrogen pools for N. viennensis culture grown on 2 mM NH4+.
| N pool (μM) | δ15N of N pool (‰) | Percent of missing N pool | Percent of ammonia oxidized | |
| Missing | 204.4 (±25.2) | −7.6 (±5.2) | ||
| Biomass | 38.8 (±3.4) | 10.1 (±0.1) | 22.8 (±4.1) | 3.1 (±0.3) |
| N2O-N | 6.5 (±0.2) | −38.1 (±0.3) | 3.5 (±0.4) | 0.5 (±0.1) |
| Unaccounted | 139.2 (±27.1) | −18.5 (±1.7) | 73.7 (±4.5) |
The missing N pool is N that was not present at NH4+ and NO2– at the last sampling time point when biomass and N2O was collected for isotope analysis. We used a mass balance approach to calculate δ15N of the missing and unaccounted N pool. Standard errors are given in parentheses.