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Gross nitrogen fixation in the oligotrophic North Pacific Ocean

贫营养北太平洋的总固氮

基本信息

批准号：
1756524
负责人：
Samuel Wilson
金额：
$ 24.71万
依托单位：
University of Hawaii
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-03-15 至 2021-02-28
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1756524&HistoricalAwards=false
关键词：
Gross nitrogen fixation oligotrophic North

项目摘要

Just as plants convert carbon dioxide into biomass for growth, some microorganisms can convert nitrogen gas from the atmosphere into biomass. This process is called nitrogen fixation and it is important ecologically because it allows microorganisms to live in habitats where they would otherwise be unable to grow. Nitrogen fixation occurs both on land and in the oceans. One of the key questions facing oceanographers today is resolving how much nitrogen fixation is occurring in the surface ocean and how it varies temporally, on timescales of days to seasons, and spatially, across different biomes. This work will develop high throughput analysis of nitrogen fixation at sea so that measurements can be made in real-time onboard oceanographic research vessels. This will help improve targeted sampling of the water-column and facilitate the comparison of nitrogen fixation with rates of photosynthesis which are currently conducted on timescales of minutes to hours. The work will be done at the Center for Microbial Oceanography: Research and Education (C-MORE) where Native Hawaiians and Pacific Islanders majoring in an ocean or earth science-related field are given opportunities for scientific training and laboratory experience. To engage the high-school students in the work and inform them about opportunities in scientific careers, we will hold one to two outreach events per year targeting sixth to eighth grade girls at local public charter schools.This research will use a highly-sensitive reduced gas analyzer to quantify the production of hydrogen gas which is a metabolic by-product of the nitrogen fixation process. To improve the detection limit, seawater samples will be sparged with the inert gas argon to inhibit the reduction of nitrogen gas by the nitrogenase enzyme. Under this scenario, nitrogenase transfers all the electrons used to reduce nitrogen gas into the production of hydrogen. This technique of amplifying the production of hydrogen via nitrogen fixation is familiar to the biohydrogen research community and will be developed for sea-going oceanographic purposes. This proposal will test the method on laboratory cultures of diazotrophs to verify the ratio of hydrogen gas production to traditional methods of nitrogen fixation analysis such as stable isotope incorporation into biomass.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

就像植物将二氧化碳转化为生物质以供生长一样，一些微生物可以将大气中的氮气转化为生物质。这个过程被称为固氮，它在生态学上很重要，因为它允许微生物生活在它们无法生长的栖息地。固氮作用在陆地和海洋中都发生。海洋学家今天面临的关键问题之一是解决海洋表面发生了多少氮固定，以及它在时间上如何变化，从几天到几个季节的时间尺度，以及不同生物群落的空间变化。这项工作将发展海上固氮的高通量分析，以便在海洋研究船上进行实时测量。这将有助于改进对水柱的有针对性的取样，并便于将固氮作用与目前以分钟至小时为时标进行的光合作用速率进行比较。这项工作将在微生物海洋学研究与教育中心（C-MORE）完成，在那里，夏威夷土著人和太平洋岛民主修海洋或地球科学相关领域，有机会获得科学培训和实验室经验。为了让高中生参与这项工作，并让他们了解科学职业的机会，我们每年将针对当地公立特许学校的六至八年级女生举办一到两次外联活动。这项研究将使用高灵敏度的还原气体分析仪来量化固氮过程中代谢副产物氢气的产生。为提高检测限，海水样品将用惰性气体氩气喷射，以抑制固氮酶还原氮气。在这种情况下，固氮酶将用于还原氮气的所有电子转移到氢气的生产中。这种通过固氮作用扩大氢生产的技术是生物氢研究界所熟悉的，将为航海海洋学目的而开发。该提案将在实验室培养的固氮菌上测试该方法，以验证氢气生产与传统固氮分析方法（如将稳定同位素掺入生物质）的比例。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Mechanistic Model for the Coexistence of Nitrogen Fixation and Photosynthesis in Marine Trichodesmium

DOI：
10.1128/msystems.00210-19
发表时间：
2019-07-01
期刊：
MSYSTEMS
影响因子：
6.4
作者：
Inomura, Keisuke;Wilson, Samuel T.;Deutsch, Curtis
通讯作者：
Deutsch, Curtis

Distinct nitrogen cycling and steep chemical gradients in Trichodesmium colonies

DOI：
10.1038/s41396-019-0514-9
发表时间：
2020-02-01
期刊：
ISME JOURNAL
影响因子：
11
作者：
Klawonn, Isabell;Eichner, Meri J.;Ploug, Helle
通讯作者：
Ploug, Helle

Evaluation of argon‐induced hydrogen production as a method to measure nitrogen fixation by cyanobacteria

氩气诱导产氢作为测量蓝藻固氮方法的评估

DOI：
10.1111/jpy.13129
发表时间：
2021
期刊：
Journal of Phycology
影响因子：
2.9
作者：
Wilson, Samuel T.;Caffin, Mathieu;White, Angelicque E.;Karl, David M.;Palenik, ed., B.
通讯作者：
Palenik, ed., B.