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

• 批准号: 0647981
• 负责人: Allan Devol
• 金额: $ 37.51万
• 依托单位: University of Washington
• 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=0647981&HistoricalAwards=false
• 关键词: Collaborative; Research; Anammox; Denitrification; Oxygen

OCE-0647981As 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-0647981作为世界海洋中三个永久性缺氧区（ODZ）的区域之一，阿拉伯海对海洋固定氮的损失和海洋一氧化二氮（N2 O）向大气的通量的重要性超出其面积的预测。普遍接受的范式，规范反硝化是负责这两个通量最近受到了挑战，发现厌氧氨氧化（anammox），甚至可能占主导地位的反硝化氮生产。由于这两个过程是由不同的生物体与完全不同的生理反应不同的环境因素，有必要准确地解决各自的贡献，以了解和预测通量的N循环。虽然传统的厌氧氨氧化孵育表明，厌氧氨氧化是唯一的途径，在ODZ的N2生产，这不能与化学计量的限制或与所观察到的分布的亚硝酸盐和N2 O的ODZ，这强烈建议反硝化。此外，从分子数据得出的群落组成和动态表明，细菌必须发挥重要作用。在这项研究中，来自普林斯顿大学和华盛顿大学的研究人员假设，传统的孵育方法倾向于人为地支持一个或另一个过程，因为它们改变了各自限制因素的浓度。为了验证这一假设，他们将研究厌氧氨氧化和反硝化作用对氧气，铵，亚硝酸盐和有机碳的反应，使用不透气袋中的大体积孵育，以获得厌氧氨氧化和反硝化作用的真实速率的现实估计。 这些实验将在阿拉伯海的一次巡航中与印度同事合作进行。这项研究更广泛影响的一个重要组成部分是普林斯顿大学和华盛顿大学的研究小组与他们在印度的合作者之间的密切合作。这一合作将提供机会，在稳定同位素和分子生态技术方面进行一定数量的技术转让。 在普林斯顿大学，该项目将雇用并为本科生提供夏季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。这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计划，所有PI将继续参与各自机构的这些计划。