山西左云县采煤区人工湿地冬季沉积物细菌群落多样性

Diversity of microbial community in winter at constructed wetlands sediment around coal mining area at Zuoyun, Shanxi province

【背景】人工湿地处理煤炭矿井废水效果显著,而关于人工湿地沉积物的细菌群落结构和特征研究较少。【目的】阐明人工湿地净化采煤区废水的效应和细菌群落结构及特征。【方法】对山西省左云县采煤区人工湿地不同采样点水质进行监测,利用高通量测序技术对人工湿地沉积物中细菌16S rRNA基因V3−V4区进行测序,分析沉积物中细菌群落组成。【结果】采煤区废水流经人工湿地后水质得到有效改善,其中生化需氧量(Biochemical oxygen demand,BOD5)、化学需氧量(Chemical oxygen demand,CODCr)、总氮(Total nitrogen,TN)、总磷(Total phosphorus,TP)去除率分别达到76.2%、93.4%、73.4%和99.3%;测序共获得2832个操作分类单元(Operational taxonomic units,OTUs),共753个属,分布于51个门的150个纲;4个采样点中优势菌门为变形菌门(Proteobacteria,50%−64.7%)和拟杆菌门(Bacteroidetes,15.8%−21.2%),变形菌门中优势菌纲为β-变形菌纲和γ-变形菌纲,其中M1、M2、M3中富含氨氮氧化细菌的β-变形菌纲和γ-变形菌纲丰度最高;M4沉积物细菌OTU最多,多样性最高;沉积物特有优势菌属Sulfurimonas、Sulfuricurvum的相对丰度与NH4+-N的含量显著负相关,Azoarcus菌属相对丰度与TN存在显著正相关,Novosphingobium菌属相对丰度与TP含量存在显著正相关。【结论】煤矿废水流经人工湿地可得到有效的净化,细菌多样性在人工湿地生态功能中起到了决定作用。

[Background]Although the coal mine wastewater treatment by constructed wetland has succeeded remarkably,few studies can be found on the structure and function of microbial communities in constructed wetlands sediment.[Objective]The purpose of this study is to clarify the effect of constructed wetland on the coal mining wastewater treatment and the structure and function of microbial community.[Methods]The water quality at different sampling sites of constructed wetland in Zuoyun,Shanxi was monitored.Based on high throughput sequencing technology,V3−V4 region of the bacterial 16S rRNA gene in constructed wetlands sediment were sequenced.Then the composition of bacterial communities in sediment were analyzed.[Results]The quality of wastewater from coal mine was effectively improved after flowing through the constructed wetland.Removal efficiencies of biochemical oxygen demand(BOD5),chemical oxygen demand(CODCr),total nitrogen(TN)and total phosphorus(TP)in constructed wetlands were 76.2%,93.4%,73.4%,99.3%,respectively.Illumina sequencing of 16S rRNA amplicons revealed that a total of 2832 operational taxonomic units(OTUs)were detected.Sequence alignment results showed that a total of 51 bacterial phyla,150 classes,and 753 genera were found.Among the 4 sampling sites,the dominant bacteria phyla were Proteobacteria(50.0%−64.7%)and Bacteroidetes(15.8%−21.2%).The sampling sites of M1,M2,and M3 had the highest abundance ofβ-Proteobacteria andγ-Proteobacteria,which were rich in ammonia nitrogen oxidation bacteria.The sampling site of M4 had the greatest number of bacterial OTUs with the highest diversity.There were significant positive correlations between the relative abundance of Azoarcus and contents of the TN,while significant negative correlations between the relative abundance of Sulfurimonas,Sulfuricurvum and the contents of NH4+-N.Moreover,the relative abundance of Novosphingobium was also positively correlated with the contents of the TP.[Conclusion]The effective treatment of coal mine wastewater is achieved after flowing through constructed wetland,and bacterial diversity plays a decisive role in the ecological function of constructed wetland.