基于数据库分析不同类型生境中厌氧氨氧化细菌的多样性分布特征

Community structure and distribution of anammox bacteria in different habitat

摘要:

[目的]厌氧氨氧化过程是一种能在厌氧条件下氧化NH₄⁺同时还原NO₂^-或者NO₃^-生成N₂的过程，是氮素循环过程的重要途径之一。厌氧氨氧化过程由厌氧氨氧化细菌催化完成，目前通过分子生物学的手段已证实了厌氧氨氧化细菌存在于多种类型的生境中，本文对厌氧氨氧化细菌在不同类型生境中的多样性分布规律进行了系统分析。[方法]基于NCBI数据库中厌氧氨氧化细菌的16S rRNA基因序列，利用Mothur分析平台系统分析了厌氧氨氧化细菌在不同生境中的多样性分布规律和特征。[结果]分析表明，海洋环境中Ca.Scalindua属的厌氧氨氧化细菌占绝对主导；淡水和农业土壤中Ca.Brocadia属的厌氧氨氧化细菌占优势；工程系统中普遍存在Ca. Brocadia和Ca. Kuenenia属的厌氧氨氧化细菌；而湿地和河口环境中厌氧氨氧化细菌多样性最高，Ca.Scalindua、Ca. Brocadia和Ca.Kuenenia属的厌氧氨氧化细菌均有较高的相对丰度，显示出了陆地与海洋交汇的显著特征。[结论]本研究系统展示了不同的生境中厌氧氨氧化细菌的多样性群落结构生境分布特征，表明环境特征差异直接影响了厌氧氨氧化细菌的种群分布和系统演化。

Abstract:

[Objective] Anaerobic ammonium oxidation is a biogeochemical process of oxidizing ammonium and reducing nitrite or nitrate to produce N₂ by anaerobic ammonium-oxidizing bacteria under anaerobic conditions, which is an important process for removing fixed nitrogen from global ecosystem. The objective of this study is to demonstrate the biogeography patterns of ammonium-oxidizing bacteria in diverse habitats.[Methods] Based on the 16S rRNA gene sequences of ammonium-oxidizing bacteria from national center for biotechnology information database, we analyzed the distribution and diversity of ammonium-oxidizing bacteria in different habitat by Mothur Software. [Results] Results showed that Ca. Scalindua dominated in marine environment. Ca. Brocadia had broad distribution in both freshwater and agricultural soils ecosystem, and it was also dominant in engineered reactors, showing the higher concentration inorganic nitrogen may facilitate Ca. Brocadia existence. Wetland and estuary ecosystem had the highest diversity of ammonium-oxidizing bacteria in which Ca. Scalindua, Ca. Brocadia and Ca. Kuenenia all had relative higher abundance. [Conclusion] This study demonstrated the community structure and distribution characteristics of ammonium-oxidizing bacteria in different habitat, suggesting that different environmental factors in different habitat affect the population distribution and phylogenetic evolution of ammonium-oxidizing bacteria.