长江口外低氧区及其邻近海域表层沉积物反硝化微生物多样性和分布特征  

Diversity and distribution of denitrifying microorganisms in the surface sediments of the hypoxic zone near the Changjiang Estuary and its offshore

作　　者：王鹏[1] 吴莹[1] 刘素美[2,3] 王晓娜 戴金龙 叶祁 Peng Wang;Ying Wu;Sumei Liu;Xiaona Wang;Jinlong Dai;Qi Ye(State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200241,China;The Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China,Qingdao 266100,Shandong Province,China;Laboratory of Marine Ecology and Environmental Science,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,Shandong Province,China)

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200241 [2]中国海洋大学海洋化学理论与工程技术教育部重点实验室,山东青岛266100 [3]青岛海洋科学与技术试点国家实验室,海洋生态与环境科学功能实验室,山东青岛266237

出　　处：《微生物学报》2021年第6期1474-1487,共14页Acta Microbiologica Sinica

基　　金：国家自然科学基金(41530960);上海市自然科学基金(18ZR1410600)。

摘　　要：【目的】微生物参与的反硝化是河口区氮损失的主要途径。【方法】本研究采用Illumina MiSeq测序方法,研究了长江口外低氧区及其邻近海域表层沉积物中nirS型和nirK型反硝化微生物群落的多样性和分布特征。【结果】样品共检测到346个nirS Operational Taxonomic Units和267个nirK Operational TaxonomicUnits,根据采样地的环境特征及nirS型和nirK型反硝化微生物群落聚类分析结果将所有OperationalTaxonomicUnits划分为低氧区、南部区域及外部深水区,其中外部深水区的样品nirS功能基因的多样性最高。各实验样地优势Operational Taxonomic Units在系统进化关系上可分为多个不同的簇。此次发现的所有优势OperationalTaxonomicUnits均属于未被培养的菌群,其中部分Operational Taxonomic Units还是首次被发现。此外还发现nirS功能基因对低氧区的环境适应性更好。【结论】我们的研究结果表明广泛存在的反硝化微生物在河口沉积物的氮循环中发挥重要作用。[Objective]Microbial denitrification is the essential process to transform nitrate into nitrogen gas in estuarine environment.[Methods]In the present study,we investigated the diversity and distribution of the nirS-type and nirK-type denitrifying microbial communities in the surface sediments of the hypoxic zone near the Changjiang Estuary and in the East China Sea by Illumina MiSeq sequencing approach.[Results]A total of 346 nirS-type and 267 nirK-type Operational Taxonomic Units were detected.Environmental characteristics of sampling site and cluster analysis of nirS and nirK divided all Operational Taxonomic Units into hypoxic,southern and deep-water groups,and the samples from the deep-water group had the highest diversity of nirS functional genes.Furthermore,the dominant Operational Taxonomic Units phylogenetically formed several clusters,representing by Operational Taxonomic Units from distinct groups.All the dominant Operational Taxonomic Units were uncultured and some of them were first retrieved.Likewise,nirS gene was more adaptable to the hypoxic condition.[Conclusion]Our results indicate that widespread denitrifying microorganisms play a critical role in nitrogen cycle in the estuarine sediments.

关 键 词：长江口 低氧区 nirS NIRK 

分 类 号：Q938[生物学—微生物学]