TABLE 2.
Percentages of isotopic labeling of DNA with 15N or 13C, calculated from qPCR data of SIP fractions
| Domain | Season | Substrate | % incorporationa |
|---|---|---|---|
| Bacteria | Summer | 15NH4 | 31 |
| 15NO3− | −4 | ||
| [15N]urea | −2 | ||
| Archaea | Summer | 15NH4 | 31 |
| 15NO3− | −5 | ||
| [15N]urea | 2 | ||
| Bacteria | Winter | 15NH4 | 9 |
| 15NO3− | 6 | ||
| [15N]urea | 30 | ||
| Archaea | Winter | 15NH4 | 23 |
| 15NO3− | 17 | ||
| [15N]urea | 35 | ||
| Bacteria | Winter | [13C]bicarbonate | 17 |
| Archaea | Winter | [13C]bicarbonate | 18 |
a
Percentages in boldface are above the 30% and 15% thresholds used as indicators that uptake of 15N- and 13C-labeled substrates had occurred, respectively.