宁夏第三排水沟底泥氮循环细菌群落结构特征  

Characteristics of Nitrogen Cycling Bacterial Community Structure in Sediments of the Third Drainage Ditch in Ningxia

作　　者：郑兰香 赵靖[2,3] 黄凌霄 ZHENG Lanxiang;ZHAO Jing;HUANG Lingxiao(School of Ecology and Environment,Ningxia University,Yinchuan 750021,China;School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Key Laboratory of Ningxia Hui Autonomous Region for Yellow River Integrated Water Network Digital Water Management,Yinchuan 750021,China;College of Information Engineering,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学生态环境学院,宁夏银川750021 [2]宁夏大学土木与水利工程学院,宁夏银川750021 [3]宁夏回族自治区黄河水联网数字治水重点实验室,宁夏银川750021 [4]宁夏大学信息工程学院,宁夏银川750021

出　　处：《环境科学与技术》2024年第2期35-44,共10页Environmental Science & Technology

基　　金：国家自然科学基金项目(42267011);宁夏自然科学基金项目(2021AAC03096)。

摘　　要：底泥是水体氮循环过程的重要场所。为揭示宁夏第三排水沟底泥氮循环细菌群落结构特征,该文在5个采样点底泥理化性质分析基础上,采用荧光定量PCR法测定硝化和反硝化功能基因丰度,并对细菌群落与环境因子进行相关性分析。研究结果表明:除三排起点底泥中pH值为6.96以外,其余点均呈弱碱性。有机碳、铵态氮、硝态氮、全氮和全磷沿沟的空间分布均呈先降低后增高趋势。在硝化菌群落中,AOB amoA基因丰度(3.16×10^(6)~7.95×10^(7)copies/g)远高于AOA amoA(5.62×10^(3)~3.76×10^(5)copies/g);反硝化菌群落中,nirS基因丰度(6.87×10^(7)~9.16×10^(8)copies/g)高于nirK(2.40×10^(7)~3.42×10^(8)copies/g)。泉古菌门是AOA主要优势菌门,变形菌门为AOB、nirK和nirS共有的主要优势菌门。底泥中的氮循环微生物群落结构与环境因素的Spearman相关性分析表明,AOA与铵态氮呈显著正相关(P<0.05),与TOC呈极显著负相关(P<0.001);AOB与pH呈显著正相关;nirS型反硝化菌与pH呈显著负相关;nirK型反硝化菌与TOC呈极显著负相关,三排底泥氮循环功能微生物群落差别较大且受理化因子影响显著。Sediments are important sites of nitrogen cycling.To explore the characteristics of the bacterial community struc⁃ture involved in nitrogen cycling in the sediments of the Third Drainage Ditch in Ningxia,based on analysis of the physico⁃chemical properties of sediments at five sampling points,fluorescent quantitative PCR was used to determine the abundance of functional genes related to nitrification and denitrification,and correlation analysis was performed between the bacterial community and environmental factors.The results showed that except for the sediment at the starting point of the Third Drain⁃age Ditch with a pH value of 6.96,the sediments at other points exhibited weak alkalinity.Organic carbon,ammonium nitro⁃gen,nitrate nitrogen,total nitrogen,and total phosphorus showed a spatial distribution trend of decreasing and then increasing along the ditch.The abundance of AOB amoA genes(3.16×10^(6)~7.95×10^(7) copies/g)in nitrifying bacteria was significantly higher than that of AOA amoA genes(5.62×10^(3)~3.76×10^(5) copies/g).Concerning denitrifying bacteria,the abundance of nirS genes(6.87×10^(7)~9.16×10^(8) copies/g)exceeded that of nirK genes(2.40×10^(7)~3.42×10^(8) copies/g).The phylum Thaumarchaeota is the predominant group of ammonia-oxidizing archaea(AOA),while the phylum Proteobacteria is the major group consist⁃ing of both ammonia-oxidizing bacteria(AOB)as well as bacteria possessing nirK and nirS genes.The spearman correlation analysis between the nitrogen cycling microbial community structure in the sediments and environmental factors indicated a significant positive correlation between AOA and ammonium nitrogen(P<0.05),as well as an extremely significant negative correlation between AOA and TOC(P<0.001).AOB exhibited a significant positive correlation with pH,while nirS-type denitrifying bacteria showed a significant negative correlation with pH,and nirK-type denitrifying bacteria showed an extremely significant negative correlation with TOC.The results indicated significant di

关 键 词：底泥 氮循环 群落结构 AOA AOB NIRK nirS 

分 类 号：X172[环境科学与工程—环境科学] X143