Determining chemical factors controlling abiotic codenitrification
Determining chemical factors controlling abiotic codenitrification
复制标题
确定控制非生物共硝化的化学因素
DOI：
10.1021/acsearthsapcechem.0c00225
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发表时间：
2021
影响因子：
3.4
通讯作者：
Phillips, Rebecca L.
中科院分区：
文献类型：
--
作者：
Wilson, Stephanie J;Song, Bongkeun;Phillips, Rebecca L.
反硝化是一种通过亚硝酸盐（NO2 -）与伴侣氮底物结合产生杂交二氮（N2）的活性脱氮途径。非生物反硝化也通过NO2 -对有机氮的亚硝化产生杂交氮，但在土壤氮循环中受约束较差。我们确定了非生物反硝化在土壤中的重要性，并研究了控制非生物反硝化的因素，使用活土壤，无菌土壤和无菌溶液。无菌土壤的非生物反硝化作用范围为0.12±0.001 ~ 0.60±0.08 nmoles29N2-N g-1day-1，占活体土壤总n2产量的2.3 ~ 8.2%。在土壤中添加有机氮素伴侣（谷氨酰胺）可增加非生物氮产量。与以往的研究一致，在ph值较低的土壤中观察到较高的速率，但在碳氮比最高的土壤中发现了最高的速率。我们进一步研究了一系列有机N伴侣以及浓度和pH对溶液中非生物共硝化的影响。与无菌土壤培养类似，非生物29n2产量与溶液pH升高呈负相关。随着底物浓度的增加和pH的降低，非生物29n2的产生率也随之增加。溶液实验还表明，有机氮伴侣的添加提高了非生物共硝化速率，其速率与有机氮伴侣的C:N比值呈正相关。该研究首次证明了在酸性土壤中通过非生物协同硝化去除N的重要性，以及有机N伴侣的C:N比是非生物协同硝化的控制因素。
Codenitrification is a reactive nitrogen (N) removal pathway producing hybrid dinitrogen (N2) by combining nitrite (NO2–) and a partner-N substrate. Abiotic codenitrification also produces hybrid N2through nitrosation of organic N by NO2–, but it is poorly constrained in soil N cycles. We determined the importance of abiotic codenitrification in soils and examined factors controlling abiotic codenitrification using live soils, sterile soils, and sterile solutions. Abiotic codenitrification in sterile soils ranged from 0.12 ± 0.001 to 0.60 ± 0.08 nmoles29N2-N g–1day–1, which accounts for 2.3 to 8.2% of total N2production measured in live soils. Increased abiotic N2production was observed in soils with the addition of an organic N partner (glutamine). Consistent with previous work, higher rates were observed in lower-pH soils, but the highest rate was found in the soil with the highest carbon:nitrogen (C:N) ratio. We further investigated a range of organic N partners and the influence of concentration and pH on abiotic codenitrification in solution. Similar to sterile soil incubations, abiotic29N2production was negatively correlated with increasing pH in solution. Greater rates of abiotic29N2production were measured as the substrate concentration increased and pH decreased. Solution experiments also showed that addition of organic N partners increased abiotic codenitrification rates, which are positively correlated with the C:N ratios of organic N partners. This is the first study demonstrating the importance of N removal through abiotic codenitrification in acidic soils and the C:N ratio of organic N partners as a controlling factor in abiotic codenitrification.