Collaborative Research: Anammox and Denitrification in the Oxygen Deficient Zone of the Arabian Sea

合作研究：阿拉伯海缺氧区的厌氧氨氧化和反硝化

基本信息

批准号：
0648026
负责人：
Bess Ward
金额：
$ 38.48万
依托单位：
Princeton University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2007
资助国家：
美国
起止时间：
2007-09-01 至 2011-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0648026&HistoricalAwards=false
关键词：
Collaborative Research Anammox Denitrification Oxygen

项目摘要

OCE-0648026As one of the three regions of the world ocean that contains a permanent Oxygen Deficient Zone (ODZ), the Arabian Sea is disproportionately more important to the loss of fixed N from the ocean and to the oceanic flux of nitrous oxide (N2O) to the atmosphere than its size would predict. The generally accepted paradigm that canonical denitrification is responsible for both of these fluxes has recently been challenged by the finding that anaerobic ammonium oxidation (anammox) may even dominate denitrification for N2 production. Because the two processes are performed by different organisms with completely different physiologies that respond differently to environmental factors, it is necessary to accurately resolve their respective contributions in order to understand and predict fluxes in the N cycle. Although conventional anammox incubations suggest that anammox is the sole pathway of N2 production in the ODZ, this cannot be reconciled with stoichiometric constraints or with observed distributions of nitrite and N2O in the ODZ, which strongly suggest denitrification. Additionally, community composition and dynamics derived from molecular data suggest that denitrifiers must play an important role. In this research, researchers from Princeton and University of Washington hypothesize that the conventional incubation methods tend to artificially favor one or the other process because they alter the concentrations of their respective limiting factors. To test this hypothesis, they will investigate the response of anammox and denitrification to oxygen, ammonium, nitrite and organic carbon using large volume incubations in gas impermeable bags to obtain realistic estimates of the true rates of anammox and denitrification. The experiments will be carried out on a cruise in the Arabian Sea in collaboration with Indian colleagues. An important component of the broader impacts of the research is a strong collaboration between the Princeton and UW groups and their collaborators in India. This cooperation will provide opportunities to engage in a certain amount of technology transfer in stable isotope and molecular ecological techniques. At Princeton, the project will employ and provide summer and senior thesis research opportunities for undergraduates, and will translate into the classroom by experience and example in the undergraduate oceanography curriculum. Both institutions support department and institutional level outreach programs for teacher training and student research, and all the PIs will continue to participate in these at their respective institutions.

OCE-0648026作为世界海洋中包含永久性缺氧区 (ODZ) 的三个区域之一，阿拉伯海对于海洋固定氮的流失和一氧化二氮 (N2O) 的海洋通量尤为重要其对大气的影响超出了其大小的预测。普遍接受的范式认为规范反硝化作用是造成这两种通量的原因，但最近发现厌氧氨氧化（厌氧氨氧化）甚至可能主导氮气生产的反硝化作用，这一发现对这一范式提出了挑战。由于这两个过程是由具有完全不同生理机能的不同生物体执行的，对环境因素的反应也不同，因此有必要准确地解析它们各自的贡献，以便理解和预测氮循环中的通量。尽管传统的厌氧氨氧化培养表明厌氧氨氧化是 ODZ 中产生 N2 的唯一途径，但这与化学计量限制或观察到的 ODZ 中亚硝酸盐和 N2O 的分布（强烈表明反硝化作用）不相符。此外，来自分子数据的群落组成和动态表明反硝化菌必须发挥重要作用。在这项研究中，普林斯顿大学和华盛顿大学的研究人员假设，传统的孵化方法往往人为地偏向于一种或另一种过程，因为它们改变了各自限制因素的浓度。为了检验这一假设，他们将在不透气袋中进行大量培养，研究厌氧氨氧化和反硝化对氧气、铵、亚硝酸盐和有机碳的响应，以获得对厌氧氨氧化和反硝化真实速率的实际估计。这些实验将与印度同事合作在阿拉伯海的一艘游轮上进行。这项研究产生更广泛影响的一个重要组成部分是普林斯顿大学和威斯康星大学研究小组及其在印度的合作者之间的密切合作。此次合作将提供在稳定同位素和分子生态技术方面进行一定量技术转让的机会。在普林斯顿大学，该项目将为本科生提供暑期和高级论文研究机会，并将通过本科海洋学课程中的经验和实例转化为课堂。两个机构都支持部门和机构层面的教师培训和学生研究外展项目，所有 PI 将继续在各自机构参与这些项目。