Distribution And Ecology Of Ammonia Oxidizing Bacteria In The Palmer LTER Study Area

Palmer LTER 研究区氨氧化细菌的分布和生态

• 批准号: 0234249
• 负责人: James Hollibaugh
• 金额: --
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0234249&HistoricalAwards=false
• 关键词: Distribution; Ecology; Ammonia; Oxidizing; Bacteria; Distribution; Ecology; Ammonia; Oxidizing; Bacteria

This project will investigate the distribution, phylogenetic affinities and ecological aspects of ammonium-oxidizing bacteria in the Palmer Long-Term Ecological Research study area. Ammonia oxidation is the first step in the conversion of regenerated nitrogen to dinitrogen gas via denitrification, a 3-step pathway mediated by three distinct guilds of bacteria. As such, ammonia oxidation is important to the global nitrogen cycle. Ammonia oxidation and the overall process of nitrification-denitrification have received little attention in polar oceans where it is significant and where the effects of climate change on biogeochemical rates are likely to be pronounced. The goals of the studies proposed here are A) to obtain more conclusive information concerning composition of Antarctic ammonia oxidizers; B) to begin characterizing their ecophysiology and ecology; and C) to obtain cultures of the organism for more detailed studies. Water column and sea ice AOB assemblages will be characterized phylogenetically and the different kinds of AOB in various samples will be quantified. Nitrification rates will be measured across the LTER study area in water column, sea ice and sediment samples. Grazing rates on AOB will be determined and their sensitivity to UV light evaluated. In addition, the significance of urea nitrogen as a source of reduced nitrogen to AOB will be assessed and the temperature response of nitrification over temperature ranges appropriate to polar regions will be evaluated. This work will provide insights into the ecology of AOB and the knowledge needed to model how water column nitrification will respond to changes in the polar ecosystems accompanying global climate change.

该项目将研究帕尔默长期生态研究领域中铵氧化细菌的分布，系统发育亲和力和生态方面。氨氧化是通过反硝化转化为氮气转化为二氮气体的第一步，这是由三个不同的细菌行为介导的三步途径。因此，氨氧化对全球氮循环很重要。氨氧化和硝化化氮化的总体过程在极大的海洋中很少受到关注，而气候变化对生物地球化学率的影响很可能会被明显。此处提出的研究的目标是a）获得有关南极氨氧化剂组成的更明确的信息； b）开始描述他们的生态生理学和生态学； c）获得有机体的培养物进行更详细的研究。水柱和海冰AOB组合将在系统发育上进行表征，并将各种样品中的不同种类的AOB进行量化。硝化率将在水柱，海冰和沉积物样品中的lter研究区域进行测量。将确定AOB上的放牧率，并评估其对紫外线的敏感性。此外，将评估尿素氮作为氮对AOB降低的来源的重要性，并将评估硝化对极性区域的硝化温度响应。这项工作将提供有关AOB生态学的见解，以及对水柱硝化方式建模所需的知识将对伴随全球气候变化的极性生态系统的变化做出反应。