北京市妫水河底泥微生物群落结构特征

Characteristics of microbial community structure in Guishui River sediment in Beijing

微生物对外界环境变化较为敏感,常被作为指示生物用于监测和反映水质情况。为满足延庆世园会和冬奥会举办对妫水河水质的调控要求,探讨妫水河底泥微生物群落结构特征及环境因子对其分布的影响。基于妫水河12个不同断面的水样和底泥样品,进行了水质、底泥理化性质分析,并对底泥的微生物群落结构特征进行了研究。结果表明,妫水河中、下游水体水质COD、NH+4 N、TN超标,其中上覆水TN含量与底泥TN含量呈极显著正相关(P=0.914);MiSeq高通量测序发现,妫水河底泥微生物共检出70门228纲1168属,变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、绿弯菌门(Chloroflexi)、厚壁菌门(Firmicutes)、蓝细菌门(Cyanobacteria)、绿菌门(Chlorobi)、疣微菌门(Verrucomicrobia)和硝化螺旋菌门(Nitrospirae)是妫水河底泥微生物群落结构中的主要菌门,在各个样品中相对丰度之和均占84%以上,其中变形菌门为第一优势门,占比达到45.3%—69.1%,而不同断面样品的优势菌属有所不同。妫水河底泥微生物群落丰度总体较高,多样性也相对较高,其中世园段D7点Ace丰富度指数和Shannon多样性指数均较其他点位低,分别为2673和6.56。RDA(redundancy analysis)分析表明,底泥氨氮和温度是影响其微生物群落结构的主要因子(F=2.92,P=0.038;F=2.81,P=0.014),妫水河底泥的优势反硝化菌属为脱氮单孢菌属和硫杆状菌属,其丰度与NH4^+ N、水温呈正相关,同时与DO呈负相关。研究结果对妫水河水生态环境保护和水质管理提供数据支撑及理论指导意义。

Microorganisms are sensitive to changes in the external environment and are often used as indicators to monitor and indicate water quality.We decided to investigate the characteristics of microbial community structure in the sediment of the Guishui River and understand the impact of environmental factors on microbial community distribution,to ensure that water quality requirements are met for hosting the World Horticultural Exhibition and Winter Olympic Games in Yanqing District.Water and sediment samples from 12 different sections of the Guishui River were collected to analyze the physical and chemical properties of water and study the microbial community structure characteristics of sediment.It was found that the water quality of chemical oxygen demand(COD),ammonia nitrogen(NH+4 N),and total nitrogen(TN),were below the standard in the middle and lower reaches of Guishui River,and the total nitrogen content of the sediment had significant positive correlation with that of the overlying water(P=0.914).The microbial community structure was investigated using MiSeq high throughput sequencing.The bacterial species detected in these samples covered 70 phyla,228 classes,and 1168 genera,and it was found that Proteobacteria,Bacteroidetes,Acidobacteria,Actinobacteria,Chloroflexi,Firmicutes,Cyanobacteria,Chlorobi,Verrucomicrobia,and Nitrospirae,were the main bacteria in the sediment,accounting for more than 84%in each sample,and the phylum Proteobacteria was most abundant,accounting for 45.3%to 69.1%of the total sample.The dominant species varied in different cross sections of the samples.The abundance and diversity of microbial communities in the sediments of Guishui River were relatively high,but the Ace richness index and the Shannon diversity index(2673 and 6.56,respectively)of the D7 point in the Shiyuan section were lower than at other points.The result of redundancy analysis showed that water dissolved ammonia nitrogen and temperature were the main environmental factors influencing the microbial communities(F=2.92,P=0.038 and F=2.81,P=0.014,respectively).The dominant bacteria in the sediments were of the genus Dechloromonas and Thiobacillus.Their abundance is positively correlated with the content of ammonia nitrogen and water temperature,and negatively correlated with the content of dissolved oxygen.The research results provide data support and theoretical guidance for ecological environment protection and water quality management of Guishui River.