Collaborative Research: Chemoautotrophy in Antarctic Bacterioplankton Communities Supported by the Oxidation of Urea-derived Nitrogen

合作研究：尿素氮氧化支持的南极浮游细菌群落的化能自养

基本信息

批准号：
1643466
负责人：
James Hollibaugh
金额：
$ 26.71万
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：
2017
资助国家：
美国
起止时间：
2017-10-01 至 2019-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643466&HistoricalAwards=false
关键词：
Collaborative Research Chemoautotrophy Antarctic Bacterioplankton

项目摘要

Part 1: The project addresses fundamental questions regarding the role of nitrification (the conversion of ammonium to nitrate by a two-step process involving two different guilds of microorganisms: ammonia- and nitrite-oxidizers)in the Antarctic marine ecosystem. Specifically, the project seeks to evaluate the contribution of primary production supported by the energy in nitrogen compounds to the overall supply of organic carbon to the food web of the Southern Ocean. Previous measurements indicate that nitrification could contribute about 9% to primary production supporting the Antarctic food web on an annual basis, but those measurements did not include the additional production associated with nitrite oxidation. Additionally, the project will aim to determine the significance of the contribution of other sources of nitrogen, (specifically organic nitrogen and urea released by other organisms) to nitrification because these contributions may not be assessed by standard protocols. Such work will aid in better understanding the basis of the energy for the Antarctic marine ecosystems on an annual basis as well as better aid in understanding the energetics of the ecosystem in times and places where primary production based on light energy is limited (i.e. during the polar night or under sea ice cover). This project will result in training a postdoctoral researcher and provide undergraduate students opportunities to gain hand-on experience with research on microbial geochemistry. The Palmer Long Term Ecological Research (LTER) activities have focused largely on the interaction between ocean climate and the marine food web affecting top predators. Relatively little effort has been devoted to studying processes related to the microbial geochemistry of nitrogen cycling, yet these are a major themes at other LTER sites. This work will contribute substantially to understanding an important aspect of nitrogen cycling and bacterioplankton production in the study area. The team will be working synergistically and be participating fully in the education and outreach efforts of the Palmer LTER, including making highlights of the findings available for posting to their project web site and participating in any special efforts they have in the area of outreach.Part 2: The proposed work will quantify oxidation rates of 15N supplied as ammonium, urea and nitrite, allowing the estimation of the contribution of urea-derived N and complete nitrification (ammonia to nitrate) to chemoautotrophy and bacterioplankton production in Antarctic coastal waters. The project will compare these estimates to direct measurements of the incorporation of 14C into organic matter in the dark for an independent estimate of chemoautotrophy. The team aims to collect samples spanning the water column: from surface water (~10 m), winter water (50-100 m) and circumpolar deep water (150 m); on a cruise surveying the continental shelf and slope west of the Antarctic Peninsula in the austral summer of 2018. Other samples will be taken to measure the concentrations of nitrate, nitrite, ammonia and urea, for qPCR analysis of the abundance of relevant microorganisms, and for studies of related processes. The project will rely on collaboration with the existing Palmer LTER to ensure that ancillary data (bacterioplankton abundance and production, chlorophyll, physical and chemical variables) will be available. The synergistic activities of this project along with the LTER activities will provide a unique opportunity to assess chemoautotrophy in context of the overall ecosystem's dynamics- including both primary and secondary production processes.

第1部分：该项目解决了有关硝化作用的基本问题（通过涉及两个不同的微生物行会的两步过程：氨和硝酸盐氧化剂在南极海洋生态系统中，铵向硝酸盐转化为硝酸盐：氨和硝酸盐氧化剂）。具体而言，该项目旨在评估氮化合物中能量支持的初级生产的贡献，对有机碳的总体供应到南大洋的食物网的整体供应。先前的测量表明，硝化可能会导致每年支持南极食品网的初级生产约9％，但这些测量值不包括与亚硝酸盐氧化相关的额外生产。此外，该项目将旨在确定其他氮来源（特别是其他生物体释放的有机氮和尿素）对硝化的重要性，因为这些贡献可能无法通过标准方案来评估。这样的工作将有助于更好地理解南极海洋生态系统的能量基础，并更好地帮助理解基于光能的初级生产的时代和地点有限（即在极地夜晚或海上冰覆盖下）。该项目将导致培训博士后研究人员，并为本科生提供获得微生物地球化学研究经验的机会。帕尔默的长期生态研究（LTER）活动主要集中在海洋气候与影响顶级捕食者的海洋食品网之间的相互作用上。相对较少的努力致力于研究与氮循环微生物地球化学相关的过程，但是这些是其他滴落地点的主要主题。这项工作将有助于理解研究区域中氮循环和细菌产生的重要方面。 The team will be working synergistically and be participating fully in the education and outreach efforts of the Palmer LTER, including making highlights of the findings available for posting to their project web site and participating in any special efforts they have in the area of outreach.Part 2: The proposed work will quantify oxidation rates of 15N supplied as ammonium, urea and nitrite, allowing the estimation of the contribution of urea-derived N and complete nitrification （硝酸盐氨）到南极沿海水域的化学自由营养和细菌产生。该项目将将这些估计值与在黑暗中直接测量14C掺入有机物中的测量值，以实现化学自由营养的独立估计。该团队的目标是收集跨越水柱的样品：从地表水（〜10 m），冬季水（50-100 m）和圆形深水（150 m）；在巡航比赛中，在2018年澳大利亚夏季的南极半岛以西的大陆架和斜坡上。将采用其他样品来测量硝酸盐，亚硝酸盐，氨和尿素的浓度，以qpcr分析相关微生物的丰度，以及相关过程的研究。该项目将依靠与现有的Palmer lter的合作，以确保将提供辅助数据（细菌丰度和生产，叶绿素，物理和化学变量）。该项目的协同活动以及批量活动将提供一个独特的机会来评估整个生态系统的动态（包括初级和二级生产过程）的背景下。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Contribution of urea-N to nitrification in the Southern Ocean west of the Antarctic Peninsula

尿素-N对南极半岛西部南大洋硝化作用的贡献

DOI：
发表时间：
2023
期刊：
Applied and environmental microbiology
影响因子：
4.4
作者：
Hollibaugh, J.T.;Okotie-Oyekan, A.;Damashek, J.;H. Ducklow, H.;Popp, B.N.;Wallsgrove, N.;Allen, T.
通讯作者：
Allen, T.

Chemoautotrophic production In continental shelf waters off the West Antarctic Peninsula

西南极半岛附近大陆架水域的化能自养生产