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-0648026AS是世界海洋三个区域之一，其中包含永久性缺氧区域（ODZ），阿拉伯海对从海洋中丢失固定的N和对一硝酸氧化二氮（N2O）的海洋损失的损失比其大小的预测更为重要。普遍接受的范例是，典型的反硝化构成对这两种通量的原因最近受到质疑，即厌氧铵氧化（Anammox）甚至可能主导N2生产的非硝化作用。由于这两个过程是由具有完全不同生理的不同生物体对环境因素做出不同反应的不同生物进行的，因此有必要准确地解决其各自的贡献，以便理解和预测N周期中的通量。尽管常规的Anammox孵育表明Anammox是ODZ中N2产生的唯一途径，但这不能与化学计量的约束或观察到的ODZ中的亚硝酸盐和N2O分布相吻合，这强烈暗示了非硝基化。此外，从分子数据中得出的社区组成和动力学表明，诺植物必须发挥重要作用。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，传统的孵化方法倾向于人为地偏爱一个或另一个过程，因为它们改变了各自的限制因素的浓度。为了检验这一假设，他们将使用大体积的气体袋中的大体积孵育，以获取对氧气不可渗透的袋中的大体积孵育，以获得对Anammox和非硝化剂的真实速率的现实估计。这些实验将与印度同事合作在阿拉伯海的一次巡游中进行。这项研究的更广泛影响的重要组成部分是普林斯顿与大学组织及其在印度的合作者之间进行了强有力的合作。这种合作将提供机会，以稳定的同位素和分子生态技术进行一定数量的技术转移。在普林斯顿，该项目将为本科生提供并提供夏季和高级论文研究机会，并以本科生海洋学课程的经验和榜样转化为课堂。这两个机构都为教师培训和学生研究提供了支持部门和机构级别的外展计划，所有PI都将继续在各自的机构中参与这些计划。