基于高通量测序的人工湿地微生物群落分析

High-throughput Sequencing Analysis of the Bacterial Communities in Constructed Wetland

为了深入探索农村生活污水人工湿地中微生物群落的物种多样性、结构多样性和功能多样性,利用高通量测序技术对系统中土壤、植物根系及砾石区域细菌16S rRNA的V3-V4区进行深度测序及PICRUSt基因功能预测。结果显示,农村生活污水人工湿地处理系统中,土壤、根系及砾石生物膜上细菌群落多样性、组成和功能各有不同,而植物根系群落结构的演变更有利于污水处理:根系细菌群落物种多样性(OTU系列总数和Shannon指数)和优势细菌种类均大于砾石或土壤;两种湿地植物(滴水观音和美人蕉)的根系细菌群落表现出一定的差异:美人蕉根系中以产碱杆菌属(27%)、黄杆菌属(29%)、溶杆菌属(30%)和假单胞菌属(13%)为优势细菌,滴水观音根系以乳球菌属(28%)、黄杆菌属(20%)和假单胞菌属(34%)为优势细菌;KEGG结果表明根系代谢功能与土壤及砾石区均存在差异(p<0.05)差异且KO基因预测证实根系代谢能力最大。COG功能预测显示美人蕉根系代谢强度高于滴水观音。农村生活污水处理的主要代谢酶基因,如双加氧酶、脱氢酶、磷酸盐脱氢酶、脲酶、硝酸还原酶和过氧化氢酶基因中脱氢酶基因的丰度最高,并且美人蕉根系的功能基因丰度值最大。这些结果为高效构建处理农村生活污水生态系统提供理论依据。

To explore the diversity of species, composition and microbial function in the bacterial community of the constructed wetland for rural sewage treatment,different areas including wetland soil, plant roots and the surface of gravels were detected by using high-throughput sequencing with 16 S rRNA and PICRUSt gene prediction. The results showed that bacterial diversities, dominant OTUs of bacterial genera and KEGG genes, COG genes, as well as several KO genes of the two plant roots were all greater than that of wetland soil or the surface of gravels, showing the plant root a primary niche for bacteria dealing with rural sewage. The analysis of Shannon indices inferred a greater bacterial diversity of the Canna root than the corresponding soil or the surface of gravels as well as the Dishlia roots. The dominant OTUs in bacterial genera of Canna root differed with that of Dishlia. For instance, the Canna root was predominant with the genus Alkaligenes(27%), Flavobacterium(29%), Lysobacter(30%) and Pseudomonas(13%), while the Dishlia root with Lactococcus(28%), Flavobacterium(20%), and Pseudomonas(34%). In addition, total relative abundance of genes(dehydrogenase, dioxygenase, phosphate dehydrogenase, urease, nitrate reductase and catalase) in the Canna root was greater than that of the Dishlia root. These results indicated the greater bacterial community structure and function in the Canna root than other areas of the constructed wetland. The findings of this study provide insights into a more efficient constructed wetland for sewage treatment.