不同气候类型下污水厂活性污泥中微生物群落比较

Meta-analysis of Microbial Communities in the Activated Sludge of Wastewater Treatment Plants Under Different Climate Types

污水处理厂的微生物群落对于水质净化十分关键,这关系到公众饮水安全和环境健康.探究中国不同气候下,污水厂微生物群落结构和多样性的变化趋势及其主要环境影响因子.应用荟萃分析方法,筛选公开数据库中采用16S rRNA基因Illumina MiSeq高通量测序技术的样品,分析中国3种气候类型(Dwa、Cfa和Cwa)下污水厂微生物群落结构和多样性变化趋势,采用凝聚力模型分析不同气候类型污水厂微生物群落的核心菌群及其相互作用,并采用分段结构方程模型(PSEM)分析不同气候类型对微生物群落结构及其多样性的影响.3种气候类型下,污水厂微生物群落结构和多样性显著不同,其群落主要受进水的水温、pH、电导率和氮浓度影响.PSEM分析发现在较大空间尺度上,纬度改变可直接影响微生物群落β多样性,而纬度改变则通过改变混合液电导率和水温来间接影响微生物群落α多样性.凝聚力模型分析发现,微生物群落稳定性在Dwa气候下最高,在Cfa气候其次,此时微生物群落通过增强一小部分关键物种间的负凝聚力来增强群落稳定性.而Cwa气候下微生物群落稳定性较低,不存在具有较强负凝聚力的关键物种.污水处理厂微生物群落结构、多样性和稳定性对气候类型敏感,其群落α多样性和β多样性对纬度变化的响应机制存在较大不同.

Microbial communities in wastewater treatment plants(WWTPs)are very important for water purification in the context of public drinking water safety and environmental health.Therefore,it is necessary to explore the trends in microbial community structure and diversity in sewage treatment plants and their main environmental impact factors under different climates in China.Based on high-throughput sequencing techniques,a meta-analysis was conducted to screen the 16 S rRNA genes in an open database.We analyzed the trends in microbial community structure and diversity in WWTPs under three climate types(Dwa,Cfa,and Cwa)in China.We then constructed cohesion models to examine the core microbial taxa and their interactions within the communities.We also used a piecewise structural equation model(PSEM)to examine the effects of different climate types on microbial community structure.The three climate types significantly affected the structure and diversity of the microbial communities,with patterns correlated with influent pH,mixed liquid temperature,conductivity,and nitrogen concentrations(P<0.05).Based on the PSEM analysis,theβ-diversity of the microbial communities was directly correlated with latitude,whileα-diversity was indirectly correlated with latitude through conductivity and water temperature.Based on the cohesion modeling,microbial community stability was the highest under Dwa climate followed by the Cfa climate.This could be explained by a small subset of highly connected taxa capable of withstanding disturbance,indicating an important stability role.In contrast,the stability of the microbial communities under the Cwa climate was low,and no species with strong negative cohesion were observed.Overall,the structure,diversity,and stability of microbial community in WWTPs were found to be sensitive to climate,and the responsive mechanisms ofα-diversity andβ-diversity with respect to latitude were distinct.