市政排水管网水力水质条件对底泥微生物组多样性的影响

Effect of Hydraulic and Water Quality Conditions on Sediment Microbiota Diversity in Municipal Drainage Network

为阐释不同水力水质工况对市政排水管网底泥微生物在门和属水平多样性的影响,应用微生物16S rRNA基因测序技术,探讨了底泥微生物组Alpha和Beta多样性、样本组间差异及其与不同环境因子之间的统计学关系及可能原因.结果表明:①底泥中优势菌门Bacteroidetes、Chloroflexi、Firmicutes、Acinetobacter等均为有机物降解类细菌,并且随着外源性碳浓度的增加,同种微生物的丰度越高;随着色氨酸类有机物种类越多,微生物群落多样性越高.②在一定范围内,剪切力越高,底泥中呈显著差异(P≤0.001)的Dechloromona(5.5%)、norank_f_Anaerolineaceae(2.3%)、Longilinea(2.8%)等厌氧细菌(主要功能是分解蛋白、碳水化合物)的丰度越高.③在一定范围内,温度越高,底泥微生物组的丰度越高.在41℃环境下,呈显著差异(P≤0.001)的优势菌门Chloroflexi(11.1%)和优势菌属Defluviicoccus(4.9%)、Candidatus_Competibacter(3.8%)的相对丰度最高,而Proteobacteria、Bacteroidetes等菌门可能因微生物蛋白质活性受温度影响,丰度降低.④在碱性环境中,只有Proteobacteria(49.4%)、Chloroflexi(10.1%)等杆状菌丰度最高,没有丝状菌.⑤SO_(4)^(2−)浓度对底泥微生物影响较小,但较高SO_(4)^(2−)浓度提高了上覆水中Methylocystis、Zavarzinia等微生物丰度,抑制了Methylocystis等厌氧微生物的生长.研究显示,重力流排水管道底泥微生物组多样性变化与水力剪切力、温度、pH、SO_(4)^(2−)及外源性碳这5个环境因子相关.

In order to explain the specific impact of different hydraulic and water quality conditions on the diversity of microbial phylum and genus in the municipal drainage network sediment,this paper uses the microbial 16S rRNA gene sequencing technology to explore the Alpha and Beta diversity of the sediment microbiome,the sample groups,differences and their statistical relationships with different environmental factors and possible causes.The results show that:(1)The dominant bacteria in the bottom silt,Bacteroidetes,Chloroflexi,Firmicutes,Acinetobacter,etc.,are all organic matter-degrading bacteria.As the concentration of exogenous carbon increases,the abundance of the same bacteria is higher.The more types of acidic organic matter,higher the diversity of bacterial communities.(2)Within a certain range,the higher the shear force,the higher the abundance of anaerobic bacteria(mainly used to decompose proteins and carbohydrates)such as Dechlomona(5.5%),Norrank_f_Anaerolineaceae(2.3%)and Longilinea(2.8%)with significant difference(P≤0.001)in sediment.(3)Within a certain range,the higher the temperature,the higher the abundance of the sediment microbiome.At 41℃,the relative abundance of dominant phylum Chloroflexi(11.1%),dominant phylum Defluviicoccus(4.9%)and Candidatus_Competitor(3.8%)with significant difference(P≤0.001)is the highest,while Proteobacteria,Bacteroidetes and other phylum may be affected by temperature due to microbial protein activity.(4)In an alkaline environment,only Proteobacteria(49.4%),Chloroflexi(10.1%)and other rod-shaped bacteria have the highest abundance and no filamentous bacteria.(5)SO_(4)^(2−)−concentration has little effect on sediment microorganisms,but higher SO_(4)^(2−)−concentration increases the abundance of Methylocystis,Zavarzinia and other microorganisms in the overlying water.It inhibits the growth of anaerobic microorganisms such as Methylocystis.The research shows that the diversity of microbiome in the sediments of gravity flow drainage pipes is related to five environmental factors:hydraulic shear,temperature,pH,SO_(4)^(2−)and exogenous carbon.