太湖沉积物反硝化功能基因丰度及其与N_2O通量的关系  

The Denitrifying Functional Gene Abundance and Its Relation with Sediment N_2O Flux in Taihu Lake

作　　者：刘德鸿[1,2,3] 文帅龙 龚琬晴 钟继承[2] 钟文辉[1] LIU Dehong;WEN Shuailong;GONG Wanqing;ZHONG Jicheng;ZHONG Wenhui(School of Geography Sciences, Nanjing Normal University, Nanjing 210023, China;State Key Laboratory of Lake Science and Environment/Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences, Nanjing 210008, China;Luoyang Key Laboratory of Symbiotic Microorganism and Green Development/Agricultural College,Henan University of Science and Technology, Luoyang 471003, China)

机构地区：[1]南京师范大学地理科学学院,江苏南京210023 [2]湖泊与环境国家重点实验室/中国科学院南京地理与湖泊研究所,江苏南京210008 [3]洛阳市共生微生物与绿色发展重点实验室/河南科技大学农学院,河南洛阳471023

出　　处：《生态环境学报》2019年第1期136-142,共7页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(41371457;41771516;41771286);中国科学院重点部署项目(KZZD-EW-10-02-1);国家水体污染控制与治理科技重大专项(2013ZX07113001)

摘　　要：温室气体N_2O的生成和排放与反硝化功能微生物关系密切,探讨沉积物反硝化微生物功能基因丰度及其与N_2O通量的关系有助于更好地理解沉积物N_2O生成与排放的微生物学机制。以太湖为研究对象,采用定量qPCR(Quantitative PCR)技术测定了太湖沉积物反硝化功能基因(nirK、nirS、norB和nosZ)丰度,阐明了太湖沉积物反消化功能基因丰度的季节变化规律,并分析了反硝化功能基因丰度与沉积物N_2O通量及其他环境因子的关系。结果表明:太湖沉积物反硝化功能基因丰度呈现夏秋季高冬春季低,具有明显的季节变化特征,norB基因丰度最高,均值为9.03×10~9 copies·g^(-1),其次为nir S基因(1.14×10~9copies·g^(-1)),nirK和nosZ基因丰度均值分别为3.04×10~8copies·g^(-1)和1.09×10~8copies·g^(-1)。沉积物TN和NO_2^-是影响反硝化功能基因丰度的重要环境因子。夏秋季沉积物N2O通量为-0.12-0.04nmol·g^(-1)·h^(-1),均值为-0.05nmol·g^(-1)·h^(-1),与反硝化功能基因(nir K、nir S和nir B)丰度呈显著正相关(P<0.05),表明反硝化过程消耗了N_2O。冬春季沉积物N_2O通量为-0.05-0.48 nmol·g^(-1)·h^(-1),均值为0.27 nmol·g^(-1)·h^(-1),与反硝化功能基因丰度不具显著相关性,表明反硝化作用可能不是N_2O产生的主要过程。The formation and emission of greenhouse gas N2O are closely related to denitrifying microorganisms.To explore the relationship between the functional gene abundance of denitrifying microorganisms and N2O flux can better understand the microbiological mechanism of the formation and emission of N2O in sediments.Taking the sediments from Taihu Lake as the research object,using quantitative q-PCR technique,we measured the denitrification gene(nirK,nirS,nirB and nosZ)abundance and clarified the seasonal variation of them in the sediments of Taihu Lake,we also analyzed the relationship between denitrification gene abundance and N 2 O flux and other key environmental factors.The results showed that the abundance of denitrifying functional genes in sediment presented obviously seasonal variation,and were high in summer and autumn and low in winter and spring.The first and second largest abundance were norB gene(mean 9.03×10^9 copies·g^-1)and nirS gene(1.14×10^9 copies·g^-1),respectively.The abundances of nirK and nosZ genes were averagely 3.04×10^8 copies·g^-1 and 1.09×10^8 copies·g^-1.TN and NO 2^-N contents were the most important factors affecting the abundance of denitrification genes.In summer and autumn the N2O flux ranged from-0.12 to 0.04 nmol·g^-1·h^-1,with a mean of-0.05 nmol·g^-1·h^-1.N 2 O flux had a significant negative correlation with denitrification gene(nirK,nirS,and nirB)abundance(P<0.05),which indicated that denitrification consumed N 2 O.In winter and spring the N2O flux ranged from-0.05 to 0.48 nmol·g^-1·h^-1,with a mean of 0.27 nmol·g^-1·h^-1.There was no significant correlation between N 2 O flux and denitrification gene abundance,indicating that denitrification was not the main process of N2O production。

关 键 词：太湖 沉积物 N 2 O 反硝化功能基因 

分 类 号：X172[环境科学与工程—环境科学]