参与碳氮循环的微生物在维持生态系统稳定性方面具有十分重要的作用。过去由于技术方法的局限，对微生物碳氮耦合循环的重要作用和调控机制认识不足。碳氮耦合功能基因是一类十分特别的功能基因，它们同时具有参与碳循环和氮循环过程的能力。本研究拟以甲基营养菌为模型，对参与碳氮耦合过程的甲烷单加氧酶、甲醇脱氢酶以及固氮酶的功能基因进行研究。利用基因敲除、高通量测序和稳定性同位素示踪等现代分子生物学技术方法研究甲基营养菌碳氮耦合功能基因的重要作用和对稀土元素的响应机制。从基因、蛋白和细胞水平阐述甲基营养菌碳氮代谢调控网络。同时，结合原位实验和实验室人工群落探讨碳氮耦合功能基因的缺失对生态系统的影响，以及稀土元素在微生物群落碳氮循环中的作用。本研究有助于我们在物种、种群和群落层面系统深入的认识稀土元素对甲基营养菌碳氮耦合功能基因的调控作用，以及甲基营养菌在生态系统结构和功能维持的重要性。

Microbes participating in the carbon-nitrogen cycle play a very important role in maintaining the stability of the ecosystem. Previously, due to the limitations of technical methods, the important role of microbial carbon-nitrogen coupling cycle and associated regulatory mechanism were insufficiently understood. Carbon-nitrogen coupled functional genes are a very special kind of functional genes that have the ability to participate in the carbon cycle and nitrogen cycle metabolic processes. This study intends to use methylotrophic bacteria as an example to study the functional genes of methane monooxygenase, methanol dehydrogenase and nitrogenase participating in carbon-nitrogen coupling. Gene knockout, high-throughput sequencing, stable isotopes tracer and other modern molecular techniques will be used to study the conversion process of carbon-nitrogen coupling functional genes of methylotrophic bacteria and the response mechanism to rare earth elements. From the gene, protein, and metabolic level, the network of carbon and nitrogen metabolism control of methylotrophic bacteria will be described and explored. At the same time, we shall combine in situ and laboratory artificial community simulation to explore the impact of the lack of carbon and nitrogen coupling function genes on ecosystems, and the role of rare earth elements in the carbon and nitrogen cycle of microbial communities. This study will helpful for us to systematically understand the role of rare earth elements in the regulation of carbon-nitrogen coupling function genes of methylotrophic bacteria at the species, population, and community levels, and the importance of methylotrophic bacteria in the maintenance of ecosystem structure and function.