共代谢调控兼性甲烷氧化菌强化氯代烃降解的动力学及生物效用研究

The enormous applications of such chlorinated hydrocarbons as trichloroethylene and chloroform to industries have caused severe water contamination. Biodegradation of chlorinated hydrocarbons has a promising future for its high efficiency and low cost. According to previous studies, resting cells of facultative methanotrophs can efficiently degrade trichloroethylene and chloroform under cometabolism conditions. Moreover, facultative methanotrophs have a distinctive advantage of metabolizing multi-carbon compounds as carbon source, thereby overcoming the shortcomings of present biodegradable technologies, such as incomplete degradation, difficult to culture, etc. In this study, GC-MS, ESEM, and PCR-DGGE will be introduced, and this study aims at: (1) tolerance domestication under complex stress factors and phylogenetic analysis were carried out, and the preferences of methane monooxygenase's amino acid codon was summarized to screen and isolate new kind of facultative methanotrophs.(2) The growth kinetics of strain cells, degradation kinetics of chlorinated hydrocarbons, and inhibition kinetics of cometabolism substrate were explored, and kinetic parameters were deduced to expound the degradable mechanism of typical chlorinated hydrocarbons. (3) The 3D bioreactor to efficiently degrade chlorinated hydrocarbons, which is the coupling of reducing methane emission, was constructed, and the law of microbial evolution was clarified to propose appropriate approaches to pollution control. Research outcomes can serve as the reference for bio-remediating water contaminated by chlorinated hydrocarbons, and accelerate the application of bioremediation to engineering field.

三氯乙烯、氯仿等氯代烃在工业上的大量应用导致了环境水体的严重污染，高效、低成本的生物降解技术是解决氯代烃污染的有效途径。前期研究发现兼性甲烷氧化菌静息细胞在共代谢条件下可高效降解三氯乙烯和氯仿，该类细菌利用多碳化合物为碳源的独特优势可有效克服现有生物处理技术存在的降解不彻底和难于扩培等缺点。据此，本项目采用GC-MS、ESEM、PCR-DGGE等检测技术和分析手段开展系列研究：（1）进行菌体的复杂胁迫因子耐受性富集驯化、分离鉴定和系统发育分析，总结甲烷单加氧酶氨基酸密码子偏好，筛选新型兼性甲烷氧化菌；（2）探究菌体细胞生长动力学、氯代烃降解动力学和共代谢底物抑制动力学，推演动力学参数，揭示典型氯代烃生物降解机理；（3）构建耦合甲烷减排的氯代烃高效降解3D生物反应器，明晰微生物演变规律，提出污染控制方案。成果可为氯代烃污染水体的生物修复提供理论依据，对推动生物修复技术的工程应用具有指导价值。

三氯乙烯、氯仿等氯代烃在工业领域的大量应用导致了环境介质的严重污染，高效、低成本的生物降解技术是解决氯代烃污染的有效途径。前期研究发现兼性甲烷氧化菌静息细胞在共代谢条件下可高效降解三氯乙烯和氯仿，该类细菌可利用多碳化合物为碳源的独特优势可有效克服现有生物处理技术存在的降解不彻底和难于扩培等缺点。据此，本项目采用GC-MS、ESEM、PCR-DGGE等检测技术和分析手段开展系列研究，并取得以下成果：（1）筛选了可高效降解氯代烃的甲烷氧化菌Methylocystis sp. JTC3，分析了JTC3菌株pmoCAB基因簇序列，推演了JTC3对TCE共代谢降解动力学；（2）基于填埋场覆盖土，富集筛选了可高效降解氯代烃的混合菌群SWA1。全面考察了SWA1对氯代烃的耐受性；分析了共代谢条件下氯代烃的抑制动力学；明晰了铜离子对TCE生物降解的影响及响应机制；构建了基于菌群SWA1的固定化细胞反应器，实现了TCE的高效去除；（3）基于填埋场覆盖土，成功构建了耦合甲烷减排的氯代烃高效降解3D实时在线监测模拟系统。构建了系统中甲烷迁移转化模型，预测了实际场地中覆盖层中甲烷氧化能力，明晰了填埋场覆盖层中TCE生物降解规律及机制转化。本项目还开展了一系列富有成效的学术交流活动，四年来，在基金的支持下，出版学术著作2部（其中主编1部中文著作，参编1部英文著作）；申请国家专利5项（已授权3项，已公开2项）；已发表论文15篇（其中6篇为SCI、EI论文，9篇为CSCD核心源刊论文）。本项目研究成果已在国内外同行中产生重要影响，研究成果可为氯代烃污染水体的生物修复提供理论依据，对推动生物修复技术的工程应用具有指导价值。