高通量测序法表征潜流人工湿地中不同植物根际细菌群落特征

High throughput sequencing analysis of microbial communities in different plant rhizosphere in subsurface-flow constructed wetland

为了研究人工湿地中植物根际、污水水质和深度等对细菌群落结构特征分布的影响,利用高通量测序技术,对人工湿地中芦苇(Phragmites communis)、香蒲(Typha orientalis Presl)2种植物根际3个不同深度细菌群落特征进行了研究.细菌群落丰富度和多样性研究结果表明,芦苇根际细菌群落丰富度和多样性均大于香蒲根际,细菌在芦苇根际周围可以更好地生存;同一植物根际细菌的丰富度和多样性随着深度的增加逐渐减少.相似度和差异性分析结果表明,相同植物根际细菌群落结构相似度较高,而不同根际群落结构有一定的差别.优势细菌菌群分析结果发现,细菌群落在门类水平上达到13门以上,优势细菌种群均以变形菌门、酸杆菌门、绿弯菌门、厚壁菌门为主,相对丰度约为55%~78%;纲类水平也达到20纲以上,主要有α-变形杆菌纲、β-变形菌、δ-变形菌纲、γ-变形菌纲、芽孢杆菌纲、酸杆菌纲、相对丰度达到50%以上,植物根际富集的主要纲类细菌是β-变形菌纲.影响细菌群落结构丰富度和多样性的主要环境因素是营养物浓度、植物、采样深度和温度.

To investigate the effects of plant types,sewage water quality and sampling depth on bacterial communities in constructed wetlands,the distribution of bacterial communities in two kinds of plants,namely Phragmites communis and Typha orientalis Presl,were measured by using highthroughput sequencing technique. The results show that the richness and diversity of bacterial communities grown around Phragmites communis’ rhizosphere were higher than that of Typha orientalis Presl,so the rhizosphere of Phragmites communis was more suitable for bacterial survival. Correspondingly,with the increasing of sampling-depth in same-kind plant,the richness and diversity of rhizosphere bacteria decreased. Additionally,the similarity analysis of bacterial communities shows that the distributions of bacterial communities in one plant were more similar than that in different plants. There were 13 phylum found in plant’ s rhizospheres. The predominant microbes were Proteobacteria,Acidobacteria,Chloroflexi and Firmicutes with their relative abundance reaching as high as 55% ~ 78%. more than 20 class were found in plant’ s rhizospheres, in which the relative abundance of Alphaproteobacteria,Betaproteobacteria,Deltaproteobacteria,Gammaproteobacteria,Bacilli and Acidobacteria took up above 50%. Bettaproteobacteria was the main group in class level. Therefore,the major factors influencing the richness and diversity of microbial communities were nutrient content,plant types,sampling depth and temperature.