低温下微污染水源人工湿地氨氧化古菌硝化反硝化耦合脱氮机理

According to the demand of basic theory of denitrification in constructed wetlands (CWs) at low temperatures, taking the typical constructed wetlands with slightly polluted source water in the middle and lower reaches of the Yangtze River and Bohai Sea as the object, with a combination of enclosed plot trials and micro cosmic incubations, and the techniques including quantitative PCR, high-throughput sequencing and isotopic tracer, this study explored the distribution of ammonium-oxidizing archaea (AOA) community and their denitrification paths in typical CWs with slightly polluted source water, cultivated highly purified AOA enrichment, investigated the metabolism threshold and denitrification activity of AOA community; regulated the efficiencies of nitrification and denitrification in CWs with slightly polluted source water at low temperatures by adding highly purified AOA enrichment, clarified the spatial-temporal pattern of highly purified AOA enrichment and local microbial organisms involved in nitrogen transformation, revealed the difference between nitrogen transformation genome and transcriptome, deeply illuminated the adaptation and long-term activity of the highly purified AOA enrichment from the hyper volume niche and trophic niche points of view; developed coupled ammonium oxidation-denitrification micro ecological models for CWs with slightly polluted source water at low temperatures, identified the contribution of AOA ammonium-oxidation and denitrification, deeply revealed the coupled ammonium-oxidation and denitrification mechanism of AOA in CWs with slightly polluted source water at low temperatures.

面向人工湿地低温脱氮基础理论需求，以长江中下游和环渤海典型区域为研究对象，将封闭小区试验和微宇宙培养实验相结合，利用定量PCR、高通量测序和同位素示踪等技术手段，探究典型微污染水源人工湿地低温脱氮系统氨氧化古菌分布规律及脱氮通径，培殖氨氧化古菌高纯度富集物，考察其氨氮代谢阈值及活性，并进行测序鉴定及表征；通过添加氨氧化古菌富集物调控微污染水源人工湿地低温硝化和反硝化脱氮效率，阐明土著氮转化功能菌群与氨氧化古菌富集物优势菌的时空演变规律，揭示不同条件下氮转化功能菌群的适应性差异，从超体积生态位和营养生态位不同视角深入阐释氨氧化古菌富集物的适应性及长效活性维育机制；创建低温下微污染水源人工湿地氨氧化古菌硝化和反硝化耦合脱氮微生态过程描述模型，明确氨氧化古菌硝化和反硝化脱氮贡献率，深入揭示低温下微污染水源人工湿地氨氧化古菌硝化和反硝化耦合脱氮机理。

针对饮用水源总氮污染问题，面向人工湿地低温脱氮基础理论需求，以长江和黄河中下游地区典型微污染水源人工湿地为研究对象，将封闭小区试验和微宇宙培养实验相结合，利用定量PCR、高通量测序和同位素示踪等技术手段，基于eDNA-SIP和单细胞活性测定建立了氨氧化古菌比细胞活性识别方法，揭示了不同类型湿地氨氧化古菌的活性贡献；通过碳氮输入功能基因群组活性调控方法，显著提升了微污染水源人工湿地低温硝化和反硝化脱氮效率，揭示了水陆交错带湿地中AOA和AOB的结构-活性及其对烯丙基硫脲暴露的响应机制，阐明了长效生物质固相碳源输入条件下淹水人工湿地中反硝化过程的分子生态机理；创建了低温下微污染水源人工湿地氨氧化古菌硝化反硝化耦合脱氮分子机理模型，明确了古菌氨氧化和反硝化释放氧化亚氮的贡献率，解决了低温下微污染水源人工湿地古菌氮转化活性高精度识别方法、氨氧化古菌硝化反硝化耦合机理等关键科学问题。.项目揭示的低温下饮用水源人工湿地氨氧化古菌硝化反硝化脱氮机理，支撑了南水北调水源地安全保障与生态修复人工湿地技术研发。自主创建的氨氧化古菌活性精细识别方法，应用于于全国不同类型的水源地氨氧化活性识别，为全国农村饮水安全巩固提升工程水源地水质安全保障关键核心技术研发提供了基础科学支撑。项目成果作为北京市科学技术奖一等奖的内容之一，由北京电视台科教频道创新者说栏目拍摄科普记录片“科技支撑，智慧治水”。依托项目发表的重要论文全文见Web of Science 数据库等相关网站。 .项目执行期间，发表标注基金号的国内外期刊论文10篇（包括Water Research期刊等高质量SCI期刊论文9篇），发表国际会议论文2篇，获北京市科学技术奖一等奖1项（省级政府科技奖励，项目负责人为第1完成人），培养中青年学术带头人1人、博士后4人、博士硕士研究生7人。