一株多功能S/N/O-杂环污染物降解菌的环境适应机制研究

S/N/O-containing heterocyclic compounds are mutagenic, carcinogenic and acutely toxic, which can cause great harm to the environment. The widespread use of such compounds has resulted in worldwide pollution. Usually, these compounds are accompanied by other pollutants, such as organic solvents, heavy metals, and antibiotics, which are toxic to bacteria and able to hinder the biodegradation. Pseudomonas strains are outstanding bacteria which possess strong degradation and environmental adaptability, and have many important applications in industry and environmental treatment. Pseudomonas putida B6-2 is a versatile degrader of S/N/O-heterocyclic compounds which can mineralize variety of heterocyclic pollutants and can grow well with the present of high concentrations of organic solvents (toluene, xylene, and benzene), heavy metals (cadmium, lead, and copper), and antibiotics. This amazing adaptation ability to extreme environment of strain B6-2 is rare for S/N/O- heterocyclic compounds degraders. This proposal will focus on the genetic adaptability to the environment and the physiological role of adaptability in catabolism of pollutants. This research will enrich the basic theory of microbial metabolism and environmental adaptation. This research could also provide guidance, fundamental knowledge, technologies for improving the microbial adaptability to environment. It is expected that the research will facilitate the development and application of microbial remediation.

S/N/O-杂环化合物有致突变性、致癌性和急性毒性，对环境造成极大危害，这类化合物的广泛使用，造成其在全球范围的扩散，而且时常和其它一些对细菌有毒害作用的污染物，如有机溶剂、重金属、抗生素等复合存在，阻碍了微生物对它们的分解。假单胞菌有很强的降解和环境适应能力，在工业和环境领域都有重要的应用价值。恶臭假单胞菌B6-2能够共降解多种S/N/O-杂环化合物，能在高浓度的有机溶剂中旺盛生长，能耐重金属镉、铅，及多种抗生素，这种极端环境适应能力在S/N/O-杂环化合物降解菌中较为罕见。本申请将研究B6-2的环境适应机制和该机制在杂环污染物分解代谢中的功能，以及环境适应与分解代谢的相互作用。本研究的成果将丰富微生物环境适应和分解代谢的基础理论，为提高功能微生物环境适应能力，提供理论基础和资源储备，为微生物修复技术的开发和应用提供一定的理论指导和实践参考。

本项目通过多组学分析及全面系统的遗传解析，发现菌株B6-2包含多种完整的芳香化合物中心代谢途径及有机溶剂耐受相关基因簇，以及趋化及基因水平转移等相关基因（簇）。借助转录组学和蛋白质组学方法，本研究鉴定了可在联苯及联苯、二苯并呋喃、苯并噻吩和咔唑的混合物共代谢过程中的关键功能基因（簇）。对菌株B6-2广谱的芳香化合物代谢能力及多组学分析芳香化合物代谢网络的研究表明，菌株B6-2是在复合污染的生物修复中具有潜在应用价值；同时，针对菌株B6-2中的外排泵蛋白及其调控蛋白，系统地研究菌株抗逆性的应答反应模式，揭示假单胞菌在复杂的极端环境下，仍可保持强大的代谢能力的环境适应机制。