目前对堆肥化过程中N2O产生的机理和途径存在较大争论，现有研究均结果缺乏微生物学证据。项目在对堆肥化过程中N2O排放规律和影响因素进行的充分研究基础上，进一步通过分子生物学技术，研究N2O产生的微生物学机理和调控因子。项目通过基于hao基因和norB基因的T-RLFP技术和定量PCR技术，研究研究堆肥化过程中硝化细菌和反硝化细菌群落结构、数量变化和演替规律；通过RNA-SIP技术和对甲烷氧化基因pmoA和氨氧化基因amoA的T-RLFP指纹分析研究甲烷氧化菌对氨气的氧化作用；利用T-RFLP和定量PCR技术，分析amoA基因、hao基因和norB基因丰度变化，研究堆肥高温期短程硝化反硝化作用对N2O产生的贡献；项目还对C/N和通风率对硝化和反硝化功能基因的调控机理进行了深入研究。最终明确堆肥化过程中N2O产生的微生物学机理和调控机理，为降低堆肥化过程中温室气体的排放提供理论基础。

Composting was a critical strategy for anthropogenic greenhouse gas mitigation, especially in low cost field. There was a great controversy about the N2O formation mechanism, and current results were short of microbiology evidence. Based on the previously research on the N2O emission pattern and impact factors, the microbiology mechanism of N2O formation and its regulation were studied in this research. Terminal restriction fragment length polymorphism analysis (T-RFLP) based on hydroxylamine oxidoreductase gene (hao) and nitrite oxidoreductase gene (norB) were used to study the composition and activities of the nitrifiers and denitrifiers. Also their abundances and succession rules were researched according to the analysis of quantitative PCR. According to the analysis of RNA-SIP and T-RFLP (based on pmoA and amoA gene), the possibility of ammonia oxidization by the methane oxidizer during the composting was evaluated. The effects of Short-cut nitrification and denitrification on the production of N2O during the thermophilic phases were also studied through the abundance changes of amoA, hao and norB genes. The T-RFLP and quantitative PCR of hao and norB under different C/N and aeration rate were conducted to study the nitrification and denitrification gene's regulation mechanism. In conclusion, the above researches will ensure the microbiology mechanism of N2O formation during the composting. These results can give a theory supports for the developing of the mitigation technologies during the composting and manure management.