复合垂直流人工湿地基质细菌群落结构变化特征

Characterization of bacterial community variations in composite vertical flow constructed wetland substrates

采用Illumina MiSeq高通量测序技术对复合垂直流人工湿地5个取样区基质中的细菌群落结构与多样性进行分析,以探究基质细菌群落结构的变化特征与驱动因素。结果表明:细菌群落丰度以及多样性随着复合垂直流人工湿地梯级处理呈现出先减后增的变化趋势,二级垂直流上行池物种丰富度最高,二级垂直流下行池物种丰富度最低;湿地中优势菌种为变形菌门、厚壁菌门、绿弯菌门、放线菌门以及拟杆菌门,此外,绿弯菌门与酸杆菌门也占有一定的比例;生境的变化使得变形菌门与拟杆菌门的群落丰度整体呈现出先增后减的变化趋势,而厚壁菌门、绿弯菌门、放线菌门的群落丰度则与其变化趋势相反;γ-变形菌纲、δ-变形菌纲、α-变形菌纲在变形菌门中丰度最高,厚壁菌门中梭状芽孢杆菌丰度最高,而放线菌门中放线菌属丰度最高;一级垂直流下行池至生物稳定塘的特征微生物各有不同;冗余分析表明,细菌菌群变化的主要驱动因子为pH、溶解氧、氨态氮、硝态氮和总氮。

Illumina MiSeq high-throughput sequencing technology was used to analyze the bacterial community structure and diversity of substrates in five sampling points in a composite vertical flow constructed wetland,to investigate the characteristics and driving factors of the change of bacterial community structure in substrates.The results showed that the abundance and diversity of bacterial communities had a trend of decreasing and then increasing with the gradient treatment of the composite vertical flow constructed wetland.The species richness of the secondary vertical flow upstream pool was the highest,while the species richness of the secondary vertical flow downstream pool was the lowest.The dominant species in the constructed wetland were Proteobacteria,Firmicutes,Chloroeclobacter,Actinobacteria and Bacteroidetes.In addition,Chloroeclobacter and Acidobacteria also occupied a certain proportion.Habitat modification had led to an overall trend of increasing and then decreasing in the abundance of phylum Proteobacteria and Bacteroidetes,and the opposite trend appeared in that of Firmicutes,Chlorobacteria and Actinobacteria.The abundance ofγ-Pro⁃teobacteria,δ-Proteobacteria andα-Proteobacteria had the highest abundance in Proteobacteria,and the abundance of Clostridium was the highest in Firmicutes,while the abundance of Horizontal Actinobacteria was the highest in Ac⁃tinobacteria.The characteristic microorganisms were different from the primary vertical flow downstream pond to the biological stabilization pond.Redundancy analysis showed that the main driving factors of the change of bacterial community were pH,dissolved oxygen,ammonia nitrogen,nitrate nitrogen and total nitrogen.