Elucidation of major contributors involved in nitrogen removal and transcription level of nitrogen-cycling genes in activated sludge from WWTPs.
Elucidation of major contributors involved in nitrogen removal and transcription level of nitrogen-cycling genes in activated sludge from WWTPs.
复制标题
阐明参与污水处理厂活性污泥脱氮和氮循环基因转录水平的主要因素
DOI：
10.1038/srep44728
复制
发表时间：
2017-03-15
影响因子：
4.6
通讯作者：
Song C
中科院分区：
文献类型：
--
作者：
Che Y;Liang P;Gong T;Cao X;Zhao Y;Yang C;Song C
对8个城市污水处理厂的活性污泥中的氮循环细菌群落进行了研究。冗余度分析(RDA)表明，温度对微生物群落结构的影响最大，其次是进水NH4+和总氮(TN)。通过构建amoA、nirSandnirK基因克隆文库，研究了氨氧化和亚硝酸盐还原菌的多样性。系统发育分析表明，所有样品中亚硝酸盐还原菌均以梭菌和中生微生物为主，亚硝酸单胞菌是唯一检测到的氨氧化细菌。对nirSandnirK基因转录水平的定量检测表明，nirS型亚硝酸盐还原细菌在亚硝酸盐还原过程中起主导作用。NirSgene转录水平与进水NH4+、TN呈显著正相关，与水力停留时间呈负相关。温度与amoA基因转录水平呈显著正相关。总体而言，本研究加深了我们对城市污水处理厂活性污泥中氨氧化和亚硝酸盐还原细菌的主要类型的了解。揭示了氮循环基因转录水平与污水处理厂运行或环境变量之间的关系，为优化运行参数、提高脱氮效果提供指导。
We investigated nitrogen-cycle bacterial communities in activated sludge from 8 municipal wastewater treatment plants (WWTPs). Redundancy analyses (RDA) showed that temperature was the most significant driving force in shaping microbial community structure, followed by influent NH4+and total nitrogen (TN). The diversity of ammonia oxidizing and nitrite reducing bacteria were investigated by the construction ofamoA, nirSandnirKgene clone libraries. Phylogenetic analysis indicated thatThaueraandMesorhizobiumwere the predominant nitrite reducing bacteria, andNitrosomonaswas the only detected ammonia oxidizing bacteria in all samples. Quantification of transcription level ofnirSandnirKgenes indicated thatnirS-type nitrite reducing bacteria played the dominant roles in nitrite reduction process. Transcription level ofnirSgene positively correlated with influent NH4+and TN significantly, whereas inversely linked with hydraulic retention time. Temperature had a strong positive correlation to transcription level ofamoAgene. Overall, this study deepened our understanding of the major types of ammonia oxidizing and nitrite reducing bacteria in activated sludge of municipal WWTPs. The relationship between transcription level of nitrogen-cycle genes and operational or environmental variables of WWTPs revealed in this work could provide guidance for optimization of operating parameters and improving the performance of nitrogen removal.