湖泊沉积物的氮代谢微生物、功能基因及代谢途径分析:以贵州省红枫湖为例  

Functional Genes and Metabolic Pathways of Nitrogen Metabolism Microorganisms in Lake Sediments:A Case Study of Hongfeng Lake,Guizhou Province

作　　者：刘倩 陈晓 李彦澄 何雨含 李江[1,2] LIU Qian;CHEN Xiao;LI Yan-cheng;HE Yu-han;LI Jiang(Key Laboratory of Karst Georesources and Environment,Ministry of Education,College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China;Guizhou Karst Environmental Ecosystem Observation and Research Station,Ministry of Education,Guiyang 550025,China)

机构地区：[1]贵州大学资源与环境工程学院,喀斯特地质资源与环境教育部重点实验室,贵阳550025 [2]贵州喀斯特环境生态系统教育部野外科学观测研究站,贵阳550025

出　　处：《环境科学》2024年第10期6086-6095,共10页Environmental Science

基　　金：国家自然科学基金青年科学基金项目(52100033);贵州省科技计划项目(黔科合支撑[2021]一般475);贵州省教育厅高等学校科技创新团队项目(黔教技[2023]056)。

摘　　要：氮循环是湖泊生态系统中物质循环和能量流动的重要过程,在湖泊沉积物中,由微生物驱动的氮循环在维持湖泊生态系统平衡中发挥了重要作用.选择贵州省红枫湖作为研究对象,采集湖泊沉积物进行理化性质分析,并利用宏基因组学技术分析沉积物中的氮代谢微生物、功能基因、代谢途径及其相互关系.结果表明,红枫湖沉积物中的氮代谢微生物主要为细菌,其相对丰度前3的优势菌属分别为硫杆菌属(Thiobacillus,16.64%)、红长命菌属(Rubrivivax,9.43%)和硝化螺旋菌属(Nitrospira,7.09%);共检测到6条氮代谢途径,分别为固氮、硝化、反硝化、同化硝酸盐还原、异化硝酸盐还原和完全硝化,主要以反硝化和异化硝酸盐还原途径为主,未检测到厌氧氨氧化途径;细菌和古菌参与了6条氮代谢途径,真核生物参与了3条途径,分别是异化硝酸盐还原、反硝化和完全硝化;氨氮、硝酸盐氮和总磷是氮代谢功能基因分布的主要环境影响因子,但在不同环境中存在差异;氮代谢功能基因与微生物之间绝大多数呈正相关关系(95.04%),其中,丰度最高且宿主最多的氮代谢基因分别为narG、narZ和nxrA.研究结果进一步阐释了贵州喀斯特地区典型湖泊的氮循环过程.The nitrogen cycle is of great importance for material circulation and energy flow in lake ecosystems.It is driven by microorganisms in lake sediments and can contribute to balancing lake ecosystems.In this study,physical and chemical properties of the sediments sampled from Hongfeng Lake in Guizhou Province were assayed and analyzed using metagenomics to reveal relevant microorganisms,functional genes,metabolic pathways,and their relationships throughout nitrogen metabolism.The results showed that bacteria were dominant,and the top three relative abundant genera were Thiobacillus(16.64%),Rubrivivax(9.43%),and Nitrospira(7.09%).Only six pathways,including nitrogen fixation,nitrification,denitrification,assimilatory nitrate reduction,dissimilatory nitrate reduction,and complete nitrification,were detected in total,of which denitrification and dissimilatory nitrate reduction were the primary processes,but anaerobic ammonia oxidation was not detected.Bacteria and archaea participated in these six pathways,while eukaryotes only functioned in dissimilatory nitrate reduction,denitrification,and complete nitrification.Ammonia nitrogen,nitrate nitrogen,and total phosphorus,as main environmental factors affecting the distribution of functional genes for nitrogen metabolism,differentiated with each other in their respective real-world conditions.A positive correlation(95.04%)was observed between the functional genes and microorganisms,and narG,narZ,and nxrA possessed the highest abundance and the highest host genes.On this basis,these findings are expected to further elucidate the nitrogen cycle of typical karst lakes in Guizhou Province.

关 键 词：红枫湖 宏基因组学 氮循环 功能基因 代谢途径 

分 类 号：X172[环境科学与工程—环境科学]