Linking abundance and community of microbial N2O-producers and N2O-reducers with enzymatic N2O production potential in a riparian zone.
Linking abundance and community of microbial N2O-producers and N2O-reducers with enzymatic N2O production potential in a riparian zone.
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DOI：
10.1016/j.scitotenv.2018.06.110
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发表时间：
2018-11
期刊：
影响因子：
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通讯作者：
Siyan Zhao;Qing Wang;Jiemin Zhou;Dongdan Yuan;G. Zhu
中科院分区：
文献类型：
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作者：
Siyan Zhao;Qing Wang;Jiemin Zhou;Dongdan Yuan;G. Zhu
河岸带作为水陆交错带，不仅是反硝化作用的热点，也是氧化亚氮（N2 O）排放的热点。由于nosZ II在N2 O减排中的潜在作用，陆地生态系统中的新兴研究已经将这种新报告的N2 O还原剂考虑在内。然而，我们的知识之间的相互作用反硝化活动和N2 O生产者和还原剂（特别是fornosZ II）在水生生态系统仍然有限。本研究以白洋淀湖滨带为研究对象，研究了白洋淀湖滨带原位N2 O通量、潜在N2 O产生速率和潜在反硝化速率及其相关基因的时空分布特征。采用实时定量PCR（qPCR）和高通量功能基因测序技术分析细菌群落结构。结果表明，不同地点和不同季节土壤微生物的活性和丰度存在很大差异。向水沉积物（不断淹没区）有最低的N2 O生产潜力在这两个季节。N2 O的潜在产生速率不仅受环境因子（含水量、NH 4+含量和TOM）的影响，而且受N2 O生产者和N2 O还原者群落结构（nirK/nirS和nosZ II/nosZ I）的影响。4个功能基因的丰度冬季均高于夏季，且均在冬季的偶涝区达到峰值。群落组成的差异主要是由水分含量驱动的。总之，我们认为，N2 O生产潜力在很大程度上是由N2 O生产者和N2 O还原者的群落结构在河岸带。增加湖泊生态系统的经常淹没面积和减少偶尔淹没面积可能有助于降低沼气产生的N2 O水平。
As aquatic-terrestrial ecotones, riparian zones are hotspots not only for denitrification but also for nitrous oxide (N2O) emission. Due to the potential role ofnosZ II in N2O mitigation, emerging studies in terrestrial ecosystems have taken this newly reported N2O-reducer into account. However, our knowledge about the interactions between denitrification activities and both N2O-producers and reducers (especially fornosZ II) in aquatic ecosystems remains limited. In this study, we investigated spatiotemporal distributions ofin situN2O flux, potential N2O production rate, and potential denitrification rate, as well as of the related genes in a riparian zone of Baiyangdian Lake. Real-time quantitative PCR (qPCR) and high-throughput sequencing targeted functional genes were used to analyze the denitrifier communities. Results showed that great differences in microbial activities and abundances were observed between sites and seasons. Waterward sediments (constantly flooded area) had the lowest N2O production potential in both seasons. Not only the environmental factors (moisture content, NH4+content and TOM) but also the community structure of N2O-producers and N2O-reducers (nirK/nirS andnosZ II/nosZ I ratios) could affect the potential N2O production rate. The abundance of the four functional genes in the winter was higher than in the summer, and the values all peaked at the occasionally flooded area in the winter. The dissimilarity in community composition was mainly driven by moisture content. Altogether, we propose that the N2O production potential was largely regulated by the community structure of N2O-producers and N2O-reducers in riparian zones. Increasing the constantly flooded area and reducing the occasionally flooded area of lake ecosystems may help reduce the level of denitrifier-produced N2O.