Compound driven differences in N2 and N2O emission from soil; the role of substrate use efficiency and the microbial community
Compound driven differences in N2 and N2O emission from soil; the role of substrate use efficiency and the microbial community
复制标题
DOI：
10.1016/j.soilbio.2016.11.028
复制
发表时间：
2017-03-01
影响因子：
9.7
通讯作者：
Baggs, Elizabeth M.
中科院分区：
文献类型：
--
作者：
Giles, Madeline E.;Daniell, Tim J.;Baggs, Elizabeth M.
有机碳是反硝化过程的重要控制因素，反硝化过程可以导致产生和减少强效温室气体一氧化二氮（N2 O）。本研究确定了不同的低分子量碳（LMW-C）化合物对一氧化二氮（N2 O）和二氮（N-2）的产生的影响，以及微生物群落的大小和结构的相关作用。我们研究了以下应用葡萄糖，谷氨酰胺或柠檬酸（250 mg C kg（-1）干土）和N-15-KNO 3（100 mg N kg（-1）干土）对桑迪壤土的影响，并利用N-15标记技术测定了固氮菌产生N-2和N2 O的情况，通过16 SrDNA片段上的T-RFLP测量的细菌群落的变化以及16 SrDNA、nirK、nirS和nosZ的基因拷贝数在144小时内的变化。葡萄糖、柠檬酸和谷氨酰胺的添加均使N-15-N-2的排放量增加，高于对照组（P < 0.05），而葡萄糖和谷氨酰胺的添加导致N14+15-N2 O的排放量高于柠檬酸的添加（P < 0.001），导致柠檬酸处理中N-15-N2 O与N-15-N-2的比率较低。16 SrDNA基因拷贝数增加后，柠檬酸和谷氨酰胺，而16 SrDNA显示出显着的变化，在所有C处理，但在不同的时间段的社区组成。nosZ基因拷贝数仅在谷氨酰胺处理的120 h显著增加（P < 0.05），nirS基因拷贝数在柠檬酸和谷氨酰胺处理的120 h显著增加（P < 0.05）。这表明，当C作为单一输入添加时，LMW-C化合物之间N-2和N2 O排放的差异不是由选择增湿剂引起的，而是可能由底物利用效率的差异和随后生长和呼吸之间C分配的差异引起的。三种选定的碳化合物对反硝化作用的不同影响表明，通过调节碳化合物的可用性，有可能降低N2 O的净排放量。(C)2016由Elsevier Ltd.出版
Organic C is an important control on the process of denitrification, a process that can result in the production and reduction of the potent greenhouse gas nitrous oxide (N2O). This study identified the influence of different low molecular weight C (LMW-C) compounds on the production of nitrous oxide (N2O) and dinitrogen (N-2) and the associated role of the size and structure of the microbial community. We examined this following application of glucose, glutamine or citric acid (250 mg C kg(-1) dry soil) and N-15-KNO3 (100 mg N kg(-1) dry soil) to a sandy loam soil and measured the production of N-2 and N2O by denitrifiers using N-15 labeling techniques, changes in the bacterial community as measured by T-RFLP on 16SrDNA fragments and changes in the gene copy number of 16SrDNA, nirK, nirS and nosZ over 144 h. Addition of glucose, citric acid and glutamine all increased emissions of N-15-N-2 above that found in the control (P < 0.05) while the addition of glucose and glutamine resulted in higher emissions of N14+15-N2O (P < 0.001) than the addition of citric acid, resulting in a lower N-15-N2O to N-15-N-2 ratio in the citric acid treatment. The 16SrDNA gene copy number increased after addition of citric acid and glutamine, whilst 16SrDNA showed significant shifts in community composition in all C treatments although over different time periods. The gene copy number of nosZ only significantly increased at 120 h in the glutamine treatment (P < 0.05) and nirS at 120 h in the citric acid and glutamine treatments (P < 0.05). This suggests that where C is added as a single input, differences in N-2 and N2O emissions between LMW-C compounds were not caused by selection for denitrifiers but likely driven by differences in substrate use efficiency and subsequent differences in C partitioning between growth and respiration. The differing influence of the three selected C compounds on denitrification indicates the potential for lowering net N2O emissions through regulation of C compound availability. (C) 2016 Published by Elsevier Ltd.