龙景湖沉积物的细菌群落垂向分布特征  

Vertical distribution of bacterial communities in sediments of Longjing Lake

作　　者：牛凤霞[1] 吉芳英[1] 赵艮[1] 张倩[1] 沈秋实[1] 何强[1] 颜海波[1] JI Fang-ying;NIU Feng-xia;ZHAO Gen;ZHANG Qian;SHEN Qiu-shi;HE Qiang;YAN Hai-bo(Key Laboratory of Three Gorges Reservoir Region’s Eco-Environment, Ministry of Education, National Centre for International Research of Low-carbon and Green Buildings,Chongqing University, Chongqing 400045, China)

机构地区：[1]重庆大学三峡库区生态环境教育部重点实验室,低碳绿色建筑国际联合研究中心,重庆400045

出　　处：《中国环境科学》2017年第6期2322-2331,共10页China Environmental Science

基　　金：国家水体污染控制与治理科技重大专项(2012ZX07307-001);重庆大学2015年研究生科研创新项目基金(CYB15041);中央高校基本业务费项目(2015CDJXY)

摘　　要：为探索不同沉积时间条件下沉积物细菌群落的垂向变化及其在湖泊生态系统物质迁移转化过程中所发挥作用,对重庆市园博园龙景湖的原有河道(OR)和新形成库湾(NB)沉积物进行了分层采样,利用变性梯度凝胶电泳(DGGE)技术并结合环境参数进行冗余分析(RDA).结果表明,OR沉积物的细菌多样性指数(H)和丰度(S)高于NB,垂向上H、S和均匀度(E)都由表层至深层先减小后增大.系统发育分析显示,龙景湖沉积物主要包含了7个门类的细菌,OR表层沉积物以δ-变形菌(Deltaproteobacteria)、拟杆菌(Bacteroidetes)和绿弯菌(Chloroflexi)为主,中层以绿弯菌为主,深层以δ-变形菌和绿弯菌为主;而NB表层和中层的主要菌种与OR深层一致,其他菌种还有Ignavibacteriae、放线菌(Actinobacteria)、厚壁菌(Firmicutes)和绿菌门(Chlorobi).RDA表明,沉积物中总氮(TN)、总硫(TS)、孔隙水的总有机碳(TOC)浓度以及平均粒径是影响细菌群落结构和分布的主要因子.通过DGGE技术所获得的细菌多与有机质的降解有关.OR的TOC、TN含量高于NB,相应的沉积物中δ-变形菌、拟杆菌、Ignavibacteriae等与有机质降解相关的细菌种类和数量较多.This study explored the vertical distribution of bacterial communities in sediments under different depositiontime and its role in the migration and transformation of substances in lake ecosystem.Stratified sediment samples werecollected respectively from Original River(OR)and New-formed Bay(NB)in Longjing Lake.Redundancy analysis(RDA)were conducted based on Denaturing Gradient Gel Electrophoresis(DGGE)technology and environmentalparameters.Results showed that Shannon-Wiener indexes(H)and Richness indexes(S)in OR were higher than those inNB and vertical change trend of H,S and Evenness(E)indexes decreased first and then increased as depth increased.Phylogenetic analysis revealed that Longjing lake mainly included seven phyla of bacteria.Deltaproteobacteria,Bacteroidetes and Chloroflexi dominated in surface layers whereas Chloroflexi dominated in middle layers of ORsediments.Deltaproteobacteria and Chloroflexi were the main phyla in deep layers of both sites.Other phyla includedIgnavibacteriae,Actinobacteria,Firmicutes and Chlorobi.RDA showed that the main factors influencing bacterialcommunity composition and distribution were total nitrogen(TN),total sulphur(TS)and the concentrations of totalorganic carbon(TOC)in pore water,as well as average particle size in sediments.Otherwise,the obtained bacteria wereclosely related to the degradation of organic matter(OM).That TOC and TN contents in OR were higher than those in NBcaused relatively higher bacteria species and abundance of Deltaproteobacteria,Bacteroidetes,and Ignavibacteriae.

关 键 词：细菌群落 垂向分布 变性梯度凝胶电泳(DGGE) 冗余分析(RDA) 

分 类 号：X171.5[环境科学与工程—环境科学]