土壤微生物对溴代阻燃剂和重金属复合污染的响应机制

With the rapid development of E-waste (electronic wastes) dismantling industry, brominated flame retardants (BFRs) and heavy metal (HM) release have resulted in severe soil environmental contamination in many e-waste recycling sites (EWRSs). The research on their ecotoxicological effects and the associated remediation technique has become a hot research topic. However, although BFRs and HM are both present in many EWRSs, there has been almost no report about their joint toxic effect on soil microbe, the dominant functional strain isolation, and the evolution mechanism of microbial remediation potential in soil. Therefore, aiming to simulate the real environmental exposure accurately, this study will select the typical BFRs (BDE209) and HM (Pb) as target contaminants to conduct this research. The key point is to establish stable DNA fingerprinting technology, and then expose the soil samples with unique toxicant exposure mode. The indoor experiments will be carried out to observe and analyze the bacterial community structure and function diversity, illustrating the molecular ecotoxicological effects on soil microbe; the new dominant functional bacteria will be isolated from the soil following the fingerprinting instruction, and then microbial remediation performance and mechanism will be discussed; the metabolic gene diversity in soil microbial community will be investigated in order to clarify the molecular mechanism of soil microorganism gradually adapting to the environmental pollution and further forming the remediation potential. The outcomes of above observations will comprehensively demonstrate the response mechanism of soil microbe after exposed to BFRs and HM compound pollution, and provide scientific basis and technical support for the risk assessment and bioremediation in EWRSs.

随着电子废弃物拆解业的迅猛发展，溴代阻燃剂（BFRs）和重金属（HM）释放对土壤环境质量构成了严重威胁。本项目针对BFRs和HM复合污染土壤中微生物生态毒理效应、优势功能菌种分离和修复潜能进化机制等研究几乎空白的现状，选择典型BFRs（十溴联苯醚，BDE209）和HM（铅，Pb）作为研究对象，首先构建稳定的DNA指纹图谱技术体系，考察复合污染对土壤微生物群落结构和功能多样性的影响，揭示生态毒理效应的分子机制；然后以分子标记为导向，从复合污染土壤中引导分离优势功能菌种，考察其修复性能和调控原理，揭示微生物作用机制；进而研究复合污染土壤中微生物群落代谢基因多样性，从分子水平探明微生物逐渐适应污染环境进而形成修复潜能的演变规律。项目成果将全面揭示土壤微生物对BFRs和HM复合污染的响应机制，以期为电子废弃物拆解场地土壤风险评价和生物修复提供科学依据和技术支持。

随着电子废弃物拆解业的迅猛发展，溴代阻燃剂（BFRs）和重金属（HMs）释放对土壤环境质量构成了严重威胁。本项目针对BFRs和HMs复合污染土壤中微生物生态毒理效应、优势功能菌种分离和修复潜能进化机制等研究几乎空白的现状，首先基于GC-EI/NCI-MS和ICP-MS建立了环境和生物样品中BFRs和12种HMs分析检测方法，调查了两类化学品在浙江台州电子垃圾拆解区陆地环境中的分布；进而选择典型BFRs（十溴联苯醚，BDE209）和HMs（铅，Pb）作为目标污染物，研究了土壤中微生物对BDE209的降解动态和Pb的转化规律；通过单次和重复暴露研究了微生物对BDE209和Pb复合胁迫的毒性响应，考察了两种化学品对土壤理化性质、酶活性、微生物量碳和微生物活性的影响；通过构建的DNA指纹图谱技术体系探究了BDE209和Pb低剂量复合污染重复处理对土壤微生物群落结构和功能多样性的影响；然后以分子标记为导向，从复合污染土壤中引导分离优势功能菌种，考察其修复性能和调控原理，揭示微生物作用机制；进而研究污染土壤中微生物群落代谢基因多样性，从分子水平探明微生物逐渐适应污染环境进而形成修复潜能的演变规律；构建了土壤-蚯蚓系统，揭示了体系中BDE209去除和Pb富集规律，从个体到分子水平探究了蚯蚓对复合胁迫的毒性响应。项目成果全面揭示了土壤生物对BFRs和HMs复合污染的响应机制，以期为电子废弃物拆解场地土壤风险评价和生物修复提供科学依据和技术支持。