完全降解萘的大肠杆菌工程菌的构建及其代谢机理解析

Naphthalene, the simplest polycyclic aromatic hydrocarbon, exists widely in the environment and poses a serious threat to human health. Biodegradation is a potential low-cost and environmentally friendly approach to contamination remediation. It is difficult for the known naphthalene-degrading bacteria to meet the diverse needs of environmental conditions and remediation methods. This problem will be solved by constructing engineering bacteria for naphthalene degradation which meet different requirements via biotechnology. Therefore, this study intends to construct a naphthalene complete degradation pathway with 17 genes by using synthetic biology technology. And the artificial degradation pathway was transformed into Escherichia coli. Naphthalene can be completely degraded into the tricarboxylic acid cycle of the engineering strain via the artificial pathway. The degradation efficiency, metabolic changes and genetic stability of engineering bacteria will be studied. The colonization ability and remediation effect of engineering bacteria in contaminated soil will be analyzed. This study will prove that artificial degradation pathway composed of several functional genes from different sources can endow the host with the ability to degrade organic pollutants by scientific and reasonable design. This study provides theoretical and technical support for the artificial construction of organic pollution remediation engineering organisms by synthetic biological means.

萘作为一种结构最简单的多环芳烃类有机污染物，广泛存在于环境中，严重威胁人类的健康。微生物降解是一种极具潜力的低成本、环境友好的污染修复方式。目前已发现的萘降解菌难以满足环境条件和修复方法的多样化需求。通过生物技术构建符合不同需求的萘降解工程菌，将在很大程度上解决这一问题。因此，本研究拟以大肠杆菌为模式生物、以完整的代谢途径为操作对象，通过合成生物学技术构建一个包含17个基因的萘完全降解途径，赋予大肠杆菌完全降解萘的能力。工程菌可以将萘通过13步连续的酶促反应完全降解，产物进入三羧酸循环而为工程菌所利用。并对工程菌的降解效率、自身代谢变化、遗传稳定性、污染土壤中的定殖能力及修复效果进行详细分析。本项研究一旦完成，将证明通过科学合理的设计，可以按需要将不同来源的功能基因组装成人工代谢系统，赋予宿主降解有机污染物的能力，为通过合成生物学手段构建有机污染高效修复工程生物提供理论和技术支持。