Table 1. Coupled biogeochemical fluxes of N. maritimus strains SCM1 and NAOA6 and responses to P limitation.
Minimum Pi turnover time (τPO4) and maximum specific affinity (α°PO4) are indicated for periods of linear rates of radiotracer uptake in each incubation. Error estimates are propagated from the SE of the related slope of linear uptake, production, or nitrification rate and/or cell counts (cf. figs. S1 to S3 and table S1). PER, percent extracellular release of assimilated C or P. nd, no data.
| Strain |
Initial Pi (nM) |
τPO4 (hour) |
α°PO4 (liter g−1cell hour−1) |
C0/Nn (mol mol−1) |
DOC0/Nn (mmol mol−1) |
PER-DOC (%) |
P0/Nn (mmol mol−1) |
DOP0/Nn (μmol mol−1) |
PER-DOP (%) |
| SCM1 | 910 | 661 ± 24 | 4.4 ± 0.3 | 0.91 ± 0.06 | 43 ± 14 | 4.7 ± 2 | 1.2 ± 0.1 | 20 ± 3 | 1.6 ± 0.2 |
| 740 | 100 ± 4 | 5.6 ± 1.6 | 0.56 ± 0.03 | 42 ± 3 | 7.6 ± 1 | 1.7 ± 0.1 | 13 ± 2 | 0.8 ± 0.1 | |
| 400 | 59 ± 3 | 13 ± 2.0 | 0.44 ± 0.07 | 45 ± 18 | 10.4 ± 4 | 1.6 ± 0.2 | 9 ± 1 | 0.6 ± 0.04 | |
| 190 | 125 ± 7 | 16 ± 3.3 | 0.95 ± 0.05 | 89 ± 32 | 9.4 ± 3 | 0.9 ± 0.03 | 12 ± 0.5 | 1.4 ± 0.1 | |
| 160 | 159 ± 3 | 66 ± 14 | 1.2 ± 0.2 | nd | nd | 2.9 ± 0.2 | 36 ± 19 | 1.2 ± 0.6 | |
| NAOA6 | 1870 | 101 ± 4 | 4.7 ± 1.6 | 0.30 ± 0.03 | 9 ± 2 | 3.1 ± 1 | 2.6 ± 0.3 | 11 ± 3 | 0.4 ± 0.1 |
| 1220 | 95 ± 3 | 5.5 ± 3.4 | 0.41 ± 0.03 | 16 ± 4 | 4.0 ± 1 | 3.0 ± 0.1 | 26 ± 14 | 0.9 ± 0.5 | |
| 160 | 8.3 ± 3.7 | 998 ± 455 | 0.18 ± 0.02 | nd | nd | 2.4 ± 0.3 | 6 ± 2 | 0.2 ± 0.1 | |
| 130 | 16 ± 0.7 | 1124 ± 605 | 0.18 ± 0.02 | nd | nd | 2.3 ± 0.3 | 7 ± 2 | 0.3 ± 0.1 | |
| <100* | 3.2 ± 0.1 | 3167 ± 593 | 0.26 ± 0.03 | nd | nd | nd | nd | nd |
*For this incubation, >10% Pi was assimilated within 20 min of radiotracer addition and therefore too quickly to presume the initial Pi concentration for subsequent calculations.