摘要
近年来,辽河口沿岸人类活动频繁,工农业活动发达,大量的氮、磷等营养物质输入至感潮河段继而排放入海,导致辽河口水体富营养化程度加剧。沉积物区域是反硝化作用的重要发生地和微生物富集地。微生物能够将沉积物中的硝酸盐及亚硝酸盐还原为N2O和N2释放到大气中,进而减轻河口生态系统氮负荷。本文中的实验采用定量PCR技术测定辽河口表层沉积物反硝化过程功能基因narG、nirK、norB、nosZ的基因丰度,结果表明,主导硝酸盐还原的narG功能基因丰度最高。使用高通量测序技术对nirK型功能基因进行测序,结果显示,在辽河口反硝化细菌中Devosia、Phaeobacter、Alcaligenes、Pseudomonas菌属丰度较高。反硝化功能基因的丰度主要受到沉积物粒径的影响,norB基因丰度与多个环境因子显著相关。nirK型反硝化细菌的群落结构和多样性主要受盐度、pH、溶解氧以及NO2−的影响。研究分析了反硝化功能基因丰度和细菌群落结构及其主要影响因子,其结果为辽河口水体富营养化中氮元素归趋的认知提供理论依据。
In recent years,the water quality of the Liaohe Estuary has been declining,and a large input of nitrogen has increased the burden on the environment.The denitrification process releases nitrogen from sediments into the atmosphere in the form of N2O and N2,which reduces the nitrogen load in the estuarine ecosystem.In this study,quantitative PCR was used to determine the levels of four denitrification functional genes narG,nirK,norB and nosZ present in the surface sediments of the Liaohe Estuary.The narG gene,which dominates nitrate reduction,was found to be the most abundant.The nirK-type denitrification functional gene was sequenced by high-throughput sequencing.The results showed that the genus of denitrifying bacteria in the Liaohe Estuary was mainly Devosia,Phaeobacter,Alcaligenes,Pseudomonas.The abundance of denitrification function genes is mainly affected by sediment properties,except that norB gene is significantly related to many environmental factors.The community structure and diversity of nirK type denitrifying bacteria are mainly affected by salinity,pH,dissolved oxygen and NO2- contents.The effects of environmental factors on the abundance and community structure of denitrifying bacteria were studied.The results provided a theoretical basis for alleviating the fate of nitrogen elements in the eutrophication of Liaohe Estuary.
作者
明红霞
陈泉睿
史银银
苏洁
于颖
樊景凤
Ming Hongxia;Chen Quanrui;Shi Yinyin;Su Jie;Yu Ying;Fan Jingfeng(State Environmental Protection Key Laboratory of Coastal Ecosystem,National Marine Environmental Monitoring Center,Dalian 116023,China;College of Environmental Science and Engineering,Dalian Maritime University,Dalian 116026,China;College of Ocean and Earth,Xiamen University,Xiamen 361005,China)
出处
《海洋学报》
CAS
CSCD
北大核心
2020年第12期82-92,共11页
基金
国家重点研发计划"全球变化及应对专项"(2016YFA0601401)
国家自然科学基金(41676115)
海洋赤潮灾害立体监测技术与应用国家海洋局重点实验室基金(MATHAB201815)。
关键词
辽河口
沉积物
NIRK
细菌群落结构
反硝化功能基因
Liaohe Estuary
sediment
nirK
bacterial community structure
functional genes of denitrifying bacteria
