Collaborative Research: Underexplored connections between nitrogen and trace metal cycling in oxygen minimum zones mediated by metalloenzyme inventories

合作研究：金属酶库存介导的含氧最低区中氮与微量金属循环之间的联系尚未充分探索

• 批准号: 1924554
• 负责人: Mak Saito
• 金额: $ 89.44万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-11-01 至 2023-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1924554&HistoricalAwards=false
• 关键词: Collaborative; Research; Underexplored; connections; between

Though scarce and largely insoluble, trace metals are key components of sophisticated enzymes (protein molecules that speed up biochemical reactions) involved in biogeochemical cycles in the dark ocean (below 1000m). For example, metalloenzymes are involved in nearly every reaction in the nitrogen cycle. Yet, despite direct connections between trace metal and nitrogen cycles, the relationship between trace metal distributions and biological nitrogen cycling processes in the dark ocean have rarely been explored, likely due to the technical challenges associated with their study. Availability of the autonomous underwater vehicle (AUV) Clio, a sampling platform capable of collecting high-resolution vertical profile samples for biochemical and microbial measurements by large volume filtration of microbial particulate material, has overcome this challenge. Thus, this research project plans an interdisciplinary chemistry, biology, and engineering effort to test the hypothesis that certain chemical reactions, such as nitrite oxidation, could become limited by metal availability within the upper mesopelagic and that trace metal demands for nitrite-oxidizing bacteria may be increased under low oxygen conditions. Broader impacts of this study include the continued development and application of the Clio Biogeochemical AUV as a community resource by developing and testing its high-resolution and adaptive sampling capabilities. In addition, metaproteomic data will be deposited into the recently launched Ocean Protein Portal to allow oceanographers and the metals in biology community to examine the distribution of proteins and metalloenzymes in the ocean. Undergraduate students will be supported by this project at all three institutions, with an effort to recruit minority students. The proposed research will also be synergistic with the goals of early community-building efforts for a potential global scale microbial biogeochemistry program modeled after the success of the GEOTRACES program, provisionally called "Biogeoscapes: Ocean metabolism and nutrient cycles on a changing planet".The proposed research project will test the following three hypotheses: (1) the microbial metalloenzyme distribution of the mesopelagic is spatially dynamic in response to environmental gradients in oxygen and trace metals, (2) nitrite oxidation in the Eastern Tropical Pacific Ocean can be limited by iron availability in the upper mesopelagic through an inability to complete biosynthesis of the microbial protein nitrite oxidoreductase, and (3) nitrite-oxidizing bacteria increase their metalloenzyme requirements at low oxygen, impacting the distribution of both dissolved and particulate metals within oxygen minimum zones. One of the challenges to characterizing the biogeochemistry of the mesopelagic ocean is an inability to effectively sample it. As a sampling platform, we will use the novel biogeochemical AUV Clio that enables high-resolution vertical profile samples for biochemical and microbial measurements by large volume filtration of microbial particulate material on a research expedition in the Eastern Tropical Pacific Ocean. Specific research activities will be orchestrated to test the hypotheses. Hypothesis 1 will be explored by comparison of hydrographic, microbial distributions, dissolved and particulate metal data, and metaproteomic results with profile samples collected by Clio. Hypothesis 2 will be tested by incubation experiments using 15NO2- oxidation rates on Clio-collected incubation samples. Hypothesis 3 will be tested by dividing targeted nitrite oxidoreductase protein copies by qPCR (quantitative polymerase chain reaction)-based nitrite oxidizing bacteria abundance (NOB) to determine if cellular copy number varies with oxygen distributions, and by metalloproteomic analyses of NOB cultures. The demonstration of trace metal limitation of remineralization processes, not just primary production, would transform our understanding of the role of metals in biogeochemical cycling and provide new ways with which to interpret sectional data of dissolved and particulate trace metal distributions in the ocean. The idea that oxygen may play a previously underappreciated role in controlling trace metals due not just to metals' physical chemistry, but also from changing biological demand, will improve our ability to predict trace metal distributions in the face of decreasing ocean oxygen content.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.

尽管稀缺且在很大程度上不溶性，但痕量金属是涉及黑暗海洋生物地球化学周期（1000m以下）的复杂化学循环的复杂酶（加快生化反应加快生化反应的蛋白质分子）的关键组成部分。 例如，金属酶在氮循环中几乎参与了所有反应。然而，尽管痕量金属与氮循环之间的直接连接，但很少探索痕量金属分布与黑暗海洋中生物氮循环过程之间的关系，这很可能是由于其研究所带来的技术挑战。 自动驾驶水下车辆（AUV）CLIO的可用性是一个采样平台，该平台能够通过大容量的微生物颗粒材料收集高分辨率的垂直剖面样品，以进行生化和微生物测量，从而克服了这一挑战。 因此，该研究项目计划了跨学科的化学，生物学和工程努力，以检验以下假设：某些化学反应（例如亚硝酸盐氧化）可能会受到上室中高质量内的金属可利用率的限制，并且在低氧气条件下，痕量金属需求对亚硝酸盐氧化细菌的需求可能会增加。 这项研究的更广泛的影响包括通过开发和测试其高分辨率和适应性抽样功能，将Clio生物地球化学AUV作为社区资源的持续开发和应用。此外，将元蛋白质组学数据沉积到最近发射的海洋蛋白门户中，以允许海洋学家和生物学界的金属检查海洋中蛋白质和冶金酶的分布。本科生将在所有三个机构中得到该项目的支持，并努力招募少数族裔学生。拟议的研究还将与早期社区建设努力的目标具有协同作用，以实现以Geotraces计划成功为模型的潜在全球微生物生物地球化学计划，该计划旨在“生物地理学：海洋代谢和养分循环”。介质在氧气和痕量金属中的环境梯度在空间上是动态的，（2）东部热带太平洋中的亚硝酸盐氧化可以受到上介质中的铁的可用性的限制在低氧气下，影响氧最小区域内溶解金属和颗粒金属的分布。表征中质海洋生物地球化学的挑战之一是无法有效采样。作为一个抽样平台，我们将使用新型的生物地球化学AUV Clio，该Clio可以通过大量的微生物颗粒物质在东部热带太平洋的研究探险中大量过滤微生物颗粒材料来实现高分辨率的垂直剖面样品进行生化和微生物测量。具体的研究活动将进行策划以检验假设。 假设1将通过比较水文，微生物分布，溶解和颗粒金属数据以及元蛋白质组学结果与Clio收集的剖面样品进行比较。假设2将通过使用15NO2-氧化速率在CLIO收集的孵育样品上进行测试。假设3将通过将靶向的亚硝酸盐氧化还原酶蛋白拷贝除以基于QPCR（定量聚合酶链反应）的基于基于氧化细菌的亚硝酸盐氧化细菌（NOB）来确定细胞拷贝数是否随氧分布和金属蛋白酶分析而变化。回忆过程的痕量金属限制的证明，不仅是主要产量，都会改变我们对金属在生物地球化学循环中的作用的理解，并提供新的方法来解释海洋中溶解和颗粒金属分布的截面数据。氧气可能不仅是由于金属的物理化学反应，而且由于改变生物学需求而在控制痕量金属方面起作用，这一想法将提高我们预测痕量金属分布的能力，面对海洋氧含量的减少。该奖项反映了NSF的法定任务，反映了通过使用基金会的智力效果和广泛的评估来进行评估。

项目成果

Dinoflagellates alter their carbon and nutrient metabolic strategies across environmental gradients in the central Pacific Ocean

• DOI: 10.1038/s41564-020-00814-7
• 发表时间: 2021-01-04
• 期刊: NATURE MICROBIOLOGY
• 影响因子: 28.3
• 作者: Cohen, Natalie R.;McIlvin, Matthew R.;Saito, Mak A.
• 通讯作者: Saito, Mak A.

Abundant nitrite-oxidizing metalloenzymes in the mesopelagic zone of the tropical Pacific Ocean

• DOI: 10.1038/s41561-020-0565-6
• 发表时间: 2020-05
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: M. Saito;M. McIlvin;D. Moran;A. Santoro;C. Dupont;P. Rafter;Jaclyn K. Saunders;D. Kaul;C. Lamborg;Marian B. Westley;F. Valois;J. Waterbury

Adaptive responses of marine diatoms to zinc scarcity and ecological implications.

• DOI: 10.1038/s41467-022-29603-y
• 发表时间: 2022-04-14
• 期刊: Nature communications
• 影响因子: 16.6

Metaproteogenomic Profile of a Mesopelagic Adenylylsulfate Reductase: Course-Based Discovery Using the Ocean Protein Portal.

• DOI: 10.1021/acs.jproteome.3c00152
• 发表时间: 2023-09-01
• 期刊: JOURNAL OF PROTEOME RESEARCH
• 影响因子: 4.4
• 作者: Paoletti, Madeline M.;Fournier, Gregory P.;Dolan, Erin L.;Saito, Mak A.
• 通讯作者: Saito, Mak A.

Minimal cobalt metabolism in the marine cyanobacterium Prochlorococcus

• DOI: 10.1073/pnas.2001393117
• 发表时间: 2020-07-07
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Hawco, Nicholas J.;McIlvin, Matthew M.;Saito, Mak A.
• 通讯作者: Saito, Mak A.