富营养化湖泊湿地厌氧氨氧化和厌氧甲烷氧化菌群落结构和功能研究

Nitrite-dependent anaerobic ammonium oxidation (ANAMMOX) and anaerobic methane oxidation (N-DAMO), which both use the nitrite as the electron acceptor, are two of the most recent discoveries in microbial nitrogen cycle and carbon cycle. The discoveries of these two microbial processes make great contributions to complete the global nitrogen cycle and carbon cycle. The previous research of the ANAMMOX process mainly focuses on its importance in artificial and marine environments. For the N-DAMO, the research of this process is just in its infancy, and only a limited number of recent studies have reported the N-DAMO process in natural ecosystems. Welands are one of the most important ecosystems on earth. The most typical eutrophic lake wetland, Wuliangsuhai wetland, was referred as a case study focusing on the key microbiological processes of ANAMMOX and N-DAMO. The abundance, diversity and community structure of the ANAMMOX bacteria and N-DAMO bacteria will be deeply analyzed by high-throughput sequencing, and the diversity and richness of key functional genes will be elucidated; and mechanisms these functional microbe's responses to the environment will be illuminated. The activities and relative significance of ANAMMOX bacteria and N-DAMO bacteria in wetland systems were investigated. The ecological effects of the ANAMMOX process and N-DAMO process in systems were assessed. The discoveries of these two microbial processes make great contributions to complete the global nitrogen cycle and carbon cycle.

基于亚硝酸盐为电子受体的厌氧氨氧化反应和厌氧甲烷氧化反应是微生物氮循环和碳循环的新内容，它们的发现对完善全球碳氮循环具有重要意义。目前关于厌氧氨氧化的研究主要集中在人工环境和海洋环境；厌氧甲烷氧化的各方面研究尚处于起步阶段，自然环境中的研究屈指可数。湿地是地球上最重要的自然生态系统之一。本项目以蒙古高原干旱区最典型的富营养化湖泊湿地—乌梁素海湖泊湿地为研究对象，采用现代微生物分子生态技术，深入研究厌氧氨氧化和厌氧甲烷氧化菌的群落结构及其分布动态，分析该类菌群关键功能基因的多样性及其丰度；测定厌氧氨氧化和厌氧甲烷氧化反应活性及其与相对作用强度的关系，评估二者的生态环境效应。以期从基质种类多样、微生物功能群及代谢活性的角度，为探索湿地碳氮循环、温室气体减排和氮素污染修复提供科学依据。

退化湿地生态系统中，基于亚硝酸盐为电子受体的厌氧氨氧化反应和厌氧甲烷氧化反应是湿地微生物氮循环和碳循环的新内容，本项目以蒙古高原干旱区最典型的富营养化湖泊湿地—乌梁素海湖泊湿地为研究对象，采用通过克隆文库、荧光定量PCR等现代分子生物学技术，深入研究厌氧氨氧化和厌氧甲烷氧化菌的群落结构及其分布动态，分析该类菌群关键功能基因的多样性及其丰度；测定厌氧氨氧化和厌氧甲烷氧化反应活性及其与环境因子间的响应关系，评估二者的生态环境效应。. 主要结果如下：（1）厌氧氨氧化菌和厌氧甲烷氧化菌在乌梁素海湿地沉积物中广泛存在，其群落结构在空间上呈现明显的异质性。（2）沉积物中厌氧氨氧化菌的群落组成以Kuenenia属、Brocadia属和Jenttenia 属为主，其中Kuenenia属占比最大。湿地沉积物中厌氧甲烷氧化菌隶属于6个属33种， Sh765B-TzT-35属于优势菌属。湿地中检测到新发现并命名的菌属MIZ17与WX65，在自然湿地生境中未见报道。（3）沉积物中存在相当数量的厌氧氨氧化菌，分布特征呈现从北到南先减少后增加的变化趋势。厌氧甲烷氧化细菌群落数量相对较少，但从水平和垂直分布均呈现出空间异质性。（4）相关性分析表明pH、TN、NO3--N和TP是影响厌氧氨氧化菌群落组成的重要环境因子。含盐量和NH4+-N是影响厌氧甲烷氧化细菌的主要环境因子。. 通过上述研究，从基质种类多样、微生物功能群及代谢活性的角度，为探索退化湿地碳氮循环、温室气体减排和氮素污染修复提供理论数据。