土壤微生物群落结构对生活源和工业源再生水灌溉的差异化响应

为研究不同来源再生水灌溉对土壤微生物群落结构的影响,以地下水灌溉土壤为对照,采用Illumina MiSeq高通量测序技术对长期利用生活源和工业源再生水灌溉的土壤微生物群落结构进行分析,进一步探究土壤环境因子及其相互作用对微生物群落结构的影响.结果表明,与地下水灌溉相比,长期生活源再生水灌溉可显著提高土壤中TOC、 DOC、 Eh、 NH~+_4-N和TP的含量,长期工业源再生水灌溉导致Cd、 Cr、 Cu、 Pb和Zn在表层土壤大量累积.再生水灌溉显著增加了土壤中Acidobacteria和Planctomycetes的相对丰度,降低了Firmicutes和Tectomicrobia的相对丰度,且不同来源再生水对土壤中功能微生物的影响不同,生活源再生水灌溉可显著增加Chloroflexi和Nitrospirae的相对丰度,而工业源再生水灌溉对Actinobacteria具有显著的抑制作用.db-RDA分析结果表明,生活源再生水灌溉土壤菌群主要受TN、 TP、 DOC和Eh影响(P0.05),工业源再生水灌溉土壤菌群主要受重金属影响(P0.05).长期再生水灌溉可改变土壤环境因子间的相互作用,进而影响微生物群落结构,生活源再生水灌溉土壤中微生物主要受DOC、 TN和TP等营养物质含量的增加和氧化还原条件的改变控制,工业源再生水灌溉土壤中微生物与重金属的积累显著相关.

Different Responses of Soil Microbial Community Structure to Irrigation with Treated Wastewater from Domestic and Industrial Sources

To investigate the long-term effects of irrigation with treated domestic and industrial wastewater on the microbial community structure of the soil, Illumina MiSeq high-throughput sequencing technology was applied. Groundwater irrigated soil was used as a control. The effects of soil environmental factors and their interactions on the microbial community structure were investigated. Compared with the groundwater irrigation, irrigation with treated domestic wastewater can significantly increase the contents of TOC, DOC, Eh, NH₄⁺-N, and TP, whereas irrigation with treated industrial wastewater can increase the contents of Cd, Cr, Cu, Pb, and Zn in the soil. Irrigation with treated wastewater also increases the relative abundance of Acidobacteria and Planctomycetes, and reduces the relative abundance of Firmicutes and Tectomicrobia. The effects of treated wastewater from different sources on functional microorganisms in soil are also different; irrigation with treated domestic wastewater can increase the relative abundance of Chloroflexi and Nitrospirae, whereas irrigation with treated industrial wastewater has negative effects on the abundance of Actinobacteria. The results of db-RDA analysis show that TN, TP, DOC, and Eh are the main factors that impact the microbial communities in soils irrigated with treated domestic wastewater (P<0.05), and heavy metals are the main factors that impact the microbial communities in soils irrigated with treated industrial wastewater (P<0.05). Compared with groundwater irrigation, treated wastewater irrigation can change the correlations between soil environmental factors, which in turn affect the microbial community structure. The growth of microorganisms in soils irrigated with treated domestic wastewater is mainly controlled by the increase in the nutrients such as DOC, TN, and TP and changes in soil redox conditions. The abundance of microorganisms in soil irrigated with treated industrial wastewater is significantly correlated with the accumulation of heavy metals.