Seasonal variation and controlling factors of anaerobic ammonium oxidation in freshwater river sediments in the Taihu Lake region of China.
Seasonal variation and controlling factors of anaerobic ammonium oxidation in freshwater river sediments in the Taihu Lake region of China.
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DOI：
10.1016/j.chemosphere.2013.07.063
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发表时间：
2013-11
期刊：
影响因子：
8.8
通讯作者：
Yongqiang Zhao;Yongqiu Xia;T. Kana;Yucheng Wu;Xiaobo Li;Xiaoyuan Yan
中科院分区：
文献类型：
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作者：
Yongqiang Zhao;Yongqiu Xia;T. Kana;Yucheng Wu;Xiaobo Li;Xiaoyuan Yan
厌氧氨氧化（anammox）是去除水体中固定氮的重要途径。然而，厌氧氨氧化物在淡水河流系统中的功能仍然不确定。在这项研究中，我们评估了发生在中国太湖地区的两条河流中的厌氧氨氧化物活性的季节性调查。将均质化的沉积物与15个N标记的NO3-和NH 4+修正物一起孵育，以确定厌氧氨氧化过程相对于典型反硝化作用的潜在重要性。用膜进样质谱法测定了泥浆中29 N2和30 N2的产生.两条河流沉积物中的潜在厌氧氨氧化速率为0.11±0.07 ~ 6.79±1.28 μmol N m− 2 h− 1，厌氧氨氧化去除的N占总N2产量的0.8±0.00%~ 10.7±0.03%。两条河流的潜在厌氧氨氧化速率在时间和空间上都存在差异，平均厌氧氨氧化速率最高和最低分别出现在夏季和初秋以及冬季。厌氧氨氧化占总N2产量的百分比变化趋势与潜在厌氧氨氧化速率变化趋势一致。水温和沉积物中NO3-含量是影响厌氧氨氧化活性的主要因素.利用条形码焦磷酸测序法在沉积物样品中检测到厌氧氨氧化细菌。河流沉积物中的16 S rRNA anammox基因序列隶属于三个类群，分别为Kuenenia、Jettenia和Scalindua。Kuenenia占优势的厌氧氨氧化细菌群落。我们的研究结果证实了厌氧氨氧化细菌的存在，但他们的作用是相对较小的，在去除固定N从淡水河流系统。
Anaerobic ammonium oxidation (anammox) has been recently recognized as an important pathway for the removal of fixed nitrogen (N) from aquatic systems. However, the functions of anammox in freshwater river systems remain uncertain. In this study, we evaluated the occurrence of anammox activity in two rivers in the Taihu Lake region in China during a seasonal survey. Homogenized sediments were incubated with 15 N-labeled NO 3-and NH 4+ amendments to determine the potential importance of the anammox process relative to canonical denitrification. Production of 29 N 2 and 30 N 2 in slurries was determined using membrane inlet mass spectrometry. Potential anammox rates in the two river sediments ranged from 0.11±0.07 to 6.79±1.28 μmol N m− 2 h− 1 and the remove of N by anammox accounted for 0.8±0.00% to 10.7±0.03% of total N 2 production. Potential anammox rates varied spatially and temporally in the two rivers, with the highest and lowest mean anammox rates appearing during summer and early autumn and during winter, respectively. The variation of the percentage of anammox to total N 2 production displayed the same trend with potential anammox rates. Water temperature and NO 3-content in sediments were the main factors affecting anammox activity. Anammox bacteria were detected in sediment samples using barcode pyrosequencing. The 16S rRNA anammox gene sequences in the river sediments were affiliated with Candidatus Kuenenia, Candidatus Jettenia, and Candidatus Scalindua, among which C. Kuenenia dominated the anammox bacterial communities. Our results confirmed the presence of anammox bacteria but their role is relatively small in removing fixed N from freshwater river systems.