大辽河口及其毗邻区域水体反硝化功能基因的定量研究  

Detection of Denitrifying Bacteria Functional Genes in Daliao River Estuary and Its Adjacent Areas by Real-Time Quantitative PCR

作　　者：李雯雯 刘瑞志[1] 徐慧韬 王丽平[1] LI Wenwen;LIU Ruizhi;XU Huitao;WANG Liping(State Environmental Protection Key Laboratory of Estuarine and Coastal Environment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China)

机构地区：[1]中国环境科学研究院,国家环境保护河口与海岸带环境重点实验室,北京100012

出　　处：《环境科学研究》2021年第11期2625-2635,共11页Research of Environmental Sciences

基　　金：国家重点研发计划项目(No.2016YFA0600903)。

摘　　要：近年来随着辽河口两岸经济的发展,大辽河水质受氮素污染越来越严重.反硝化作用是微生物介导的氮循环中一个重要过程,对河口水体中过量氮素的去除和富营养化的缓解意义重大.因此,开展大辽河口水体反硝化作用的研究尤为重要.以大辽河入海河段、大辽河河口和近岸海域为研究对象,采用实时定量PCR法对其进行了水体中反硝化细菌(以功能基因nir S、nir K和nos Z为主)的空间分布特征研究,并通过因子分析和冗余分析(RDA)研究了基因丰度与环境因子间的相关性.结果表明:①不同站位大辽河口及其毗邻区域的水样中nir K、nir S和nos Z基因的丰度变化范围分别为7.73×10^(5)~2.54×10^(8)、3.19×10^(5)~3.19×10^(7)、3.22×10^(3)~4.92×10^(5) copies L,各基因平均值大小表现为nir K>nir S>nos Z;3种基因中,nir K和nir S基因大多在调查河流的上游和入海口站位丰度较高,而nos Z基因丰度在河流段由上游到河口逐渐增高,且由河口到近海呈现降低的趋势.②大辽河口及其毗邻区域(nir K+nir S)nos Z在3.23×101~1.76×10^(3)之间,平均值为454.77,表明存在较多的N 2O气体排放,特别是河口到近海区域.③ρ(As)、ρ(Cd)、ρ(Cr)、ρ(SiO_(3)2-)、ρ(NO_(3)-)、T、pH和盐度主导了大辽河口及毗邻区域水环境的整体状况,应继续关注主导因子对水环境的影响;水环境因子对反硝化功能基因丰度影响的相关性大小表现为ρ(DO)>ρ(TN)>ρ(NO_(2)-)>ρ(SiO_(3)2-)>ρ(Cd)>ρ(NO_(3)-)>盐度>ρ(As)>ρ(Cr)>T>ρ(Zn)>pH,蒙特卡罗检验得出无显著影响的因子,因此大辽河口及毗邻区域反硝化功能基因丰度是由各项环境因子相互作用、共同影响的结果.研究显示,水体中反硝化有关的微生物对环境的响应不同,各项环境因素共同控制了群落组成,为了更好地进行水体治理与保护,应持续关注水体中的反硝化功能基因.In recent years,the water quality of the Daliao River is becoming more and more seriously polluted by nitrogen with the economic development on both sides of the Loaohe estuary.Denitrification is an important process in the nitrogen cycle mediated by microorganisms,which is of great significance to the removal of excess nitrogen in the estuary water and the alleviation of eutrophication.So,it is particularly important to conduct a research on the denitrification in the Daliao River estuary and its adjacent areas.This paper takes the Daliao River Basin,estuary and coastal waters as the research object,uses real-time quantitative PCR to analyze the spatial distribution characteristics of denitrifying bacteria(mainly functional genes nir S,nir K and nos Z)in the water,and study the correlation between environmental factors and gene abundance by factor analysis and redundancy analysis(RDA).The results show that:(1)The variation ranges of nir K,nir S and nos Z genes in water samples are 7.73×10^(5)-2.54×10^(8) copies L,3.19×10^(5)-3.19×10^(7) copies L,3.22×10^(3)-4.92×10^(5) copies L,respectively.The average value of the three genes is in descending order nir K>nir S>nos Z.Among the three genes,most of the nir K and nir S genes have higher concentrations in the upper reaches of the investigated rivers and at the estuary sites,while the abundance of nos Z genes gradually increases from the upstream station to the estuary station in the river section,and decreases from the estuary to the coastal waters.(2)The(nir K+nir S)nos Z of the Daliao River Estuary and its adjacent areas are between 3.23×101-1.76×10^(3),with an average value of 454.77,indicating that there are more N 2O gas emissions,especially from the estuary to the offshore area.(3)As,Cd,Cr,SiO_(3)2-,NO_(3)-,T,pH and salinity dominate the overall condition of the water environment in the Daliao River Estuary and adjacent areas.The correlation of the influence of water environmental factors on the abundance of denitrification functional genes isρ(DO)>ρ

关 键 词：大辽河口 反硝化 水体 实时定量PCR 环境因子 

分 类 号：X171.5[环境科学与工程—环境科学]