城市污水处理系统真核微生物群落特性与地域性差异

城市污水处理厂是控制水污染、保证城市与人类可持续发展的重要设施.真核微生物作为活性污泥系统中不可或缺的一部分,在指示活性污泥性质、预测出水水质、强化净化效果、保障系统稳定运行过程中发挥着重要作用.本研究以来自北京、深圳和无锡的14个城市污水处理厂的61份样品为研究对象,采用18S r DNA高通量测序技术并结合多种生态学及统计学相关分析方法,探讨了活性污泥系统内真核微生物群落特性与地域性差异.结果表明,不同空间尺度下,活性污泥系统内真核微生物群落优势种群组成相似,在Devision水平上,群落优势种群主要由真菌、原生动物(纤毛亚门)和后生动物组成,三者相对丰度之和高达86. 22%～89. 40%.不同城市污水处理厂活性污泥系统内真核微生物多样性存在差异,无锡群落的多样性(丰富度和香农-威纳多样性指数)最高,北京的最低,且3个城市的活性污泥系统内真核微生物群落结构存在显著的地域性差异. partial mantel test和多元回归矩阵分析结果表明,曝气池混合液温度和出水总氮浓度与活性污泥系统内真核微生物群落结构的相关性较强.研究结果深化了对污水处理系统中真核微生物的认识.

Characteristics and Regional Heterogeneity of Eukaryotic Microbial Community in Wastewater Treatment Plants

Wastewater treatment plants (WWTPs) are important facilities to control water pollution and ensure the sustainable development of cities and humans. As an indispensable part of the activated sludge (AS) system, eukaryotic microbes play important roles in indicating the properties of AS, predicting the quality of the effluent, enhancing the purification effect, and ensuring a stable performance of the system in WWTPs. In this study, 61 AS samples from 14 full-scale WWTPs of Beijing, Shenzhen, and Wuxi were collected. Characteristics and regional heterogeneity of eukaryotic microbial community were elucidated via high-throughput sequencing (HTS) of the 18S rDNA and multi ecological and statistical methods. Results showed that eukaryotic microbial communities in different scales shared similar main members, which were mainly composed of fungi, ciliophora, and metazoa in division level with their total relative abundance up to 86.22%-89.40%. Diversity of eukaryotic microbial community in WWTPs of different cites varied. Richness and Shannon Wiener index of eukaryotic microbial communities in the AS system of Wuxi were the highest, while that of Beijing was the lowest. Diversity of eukaryotic microbes from HTS in this study was higher than that of conventional methods, but lower than the diversity of bacteria in AS systems. Regional heterogeneity of eukaryotic microbial community structure was uncovered by nonmetric multidimensional scaling based on Bray-Curtis distance and dissimilarity analysis. Results of partial mantel test and multiple regression matrix analysis showed that the eukaryotic microbial community was significantly correlated with the temperature of the aeration tank mixture and the total nitrogen concentration of the effluent of the AS system. These results help deepen the understanding of eukaryotic microbes in WWTPs.