Abstract
Although recent studies have explored dissimilatory nitrate reduction to ammonium (DNRA), little is known about the dependence of this process on temperature. A laboratory experiment was conducted to investigate if temperature regulates nitrate (NO3ˉ) reduction by DNRA and denitrification. Soil samples were incubated at 10 to 40 °C for 28 days, and 15N tracer methods were applied to estimate the reduction of 15NO3ˉ to 15NH4+ by DNRA organisms and to 15N2O or 15N2 by denitrifiers. Raising the temperature from 10 to 40 °C increased DNRA, which contributed to enrichment of the NH4+ pool, particularly at 40 °C. The percentage of 15NO3ˉ reduced by DNRA was from 4 to 30% of that reduced by denitrification, and decreased with increasing temperature. DNRA and denitrification were positively correlated with the abundance of nrfA and nosZ genes, respectively. The accumulation of 15NH4+ slowed in the final 12 h of sampling times, which may be due to a re-conversion of 15NH4+ to 15NO3ˉ by nitrification. High temperatures (30 to 40 °C) enhanced 15N2 production, which suggests that temperature plays an important role in regulating complete denitrification from NO3ˉ to N2.
Original language | English |
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Pages (from-to) | 363-372 |
Number of pages | 10 |
Journal | Biology and Fertility of Soils |
Volume | 57 |
Issue number | 3 |
DOIs | |
Publication status | Published - Apr 2021 |
Externally published | Yes |