Collaborative Research: Pressure effects on microbially-catalyzed organic matter degradation in the deep ocean

合作研究：压力对深海微生物催化有机物降解的影响

• 批准号: 2241720
• 负责人: Carol Arnosti
• 金额: $ 65.93万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2241720&HistoricalAwards=false
• 关键词: Collaborative; Research; Pressure; effects; microbially

Microbes are important players in the carbon cycle in the ocean. These organisms consume organic carbon and produce carbon dioxide in marine systems. Because the average depth of the ocean is 4000 m, microbes must work at high pressures typical of the deep ocean (1000 m). Although high pressure is known to affect marine microbes, their carbon cycling activities have mostly been measured at surface ocean pressures. As a result, it remains unknown how closely these measurements reflect the activities of deep-sea microbes at high pressures. As a result of collaborations with scientists in Denmark and Germany, this project will be able to use special equipment to investigate the effects of high pressures on marine microbes and their carbon cycling activities. This work is necessary to quantify rates of carbon cycling and identify the microbes involved, especially in deep waters. The project will provide training for diverse undergraduate and graduate students, and a postdoc who will conduct novel research in the U.S., Denmark, and Germany, both at sea and in the lab. The scientists will also teach middle school students about the role of microbes in the carbon cycle and pressure effects on life in the ocean. The project will provide internships for high school students, focusing on first-generation students who would like to go to college. This work may aid in future efforts to identify enzymes that function well under high pressure. Heterotrophic microbes (e.g., bacteria and archaea) are found throughout the ocean. Their biogeochemical functions help determine the rates and locations at which carbon and nutrients are regenerated, as well as the extent to which organic matter is preserved. Although research has shown that pressure profoundly affects the activities of marine microbes, most investigations of microbial communities of the deep sea are conducted at atmospheric pressure, due to the limited availability of specialized equipment. In collaboration with the Danish Center for Hadal Research at the University of Southern Denmark, this study will identify the effects of pressure on microbial communities and their extracellular enzymes of pressures characteristic of bathy- and abyssopelagic depths. At sea and in the lab, the scientific team will compare the effects of depressurization on the activities of enzymes produced by microbial communities of the deep ocean, as well as the effects of high pressure on surface-water derived enzymes and communities. Fieldwork will take place in Danish coastal waters, well as in the open North Atlantic and Pacific Oceans. Using pressurization systems and in situ incubations, this study will measure hydrolysis rates of peptides and polysaccharides, two of the major classes of marine organic matter. Project activities will also focus on developing the means to measure enzyme activities in situ in the deep ocean. In collaboration with colleagues from the Max Planck Institute for Marine Microbiology in Germany, this proect will additionally investigate whether pressure affects the selfish uptake of polysaccharides. These studies will provide new insight into understudied but key factors that help determine the fate of organic matter in the deep ocean.This project is funded by the Biological and Chemical Oceanography Programs.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.

微生物是海洋碳循环中的重要参与者。这些生物在海洋系统中消耗有机碳并生产二氧化碳。由于海洋的平均深度为4000 m，因此微生物必须在典型的深海（1000 m）的高压下工作。尽管已知高压会影响海洋微生物，但它们的碳循环活性主要是在地表海压下测量的。结果，这些测量结果如何反映高压下深海微生物的活性。由于与丹麦和德国的科学家的合作，该项目将能够使用特殊设备来研究高压对海洋微生物及其碳循环活动的影响。这项工作对于量化碳循环速率并确定所涉及的微生物是必要的，尤其是在深水中。该项目将为多元化的本科和研究生提供培训，以及在海上和实验室中在美国，丹麦和德国进行新颖研究的博士后。科学家还将向中学生传授微生物在碳循环中的作用以及对海洋生命的压力影响。该项目将为高中生提供实习，专注于想上大学的第一代学生。这项工作可能有助于将来努力确定在高压下良好发挥作用的酶。在整个海洋中都发现了杂营的微生物（例如细菌和古细菌）。它们的生物地球化学功能有助于确定碳和养分再生的速率和位置，以及保留有机物的程度。尽管研究表明，压力会深刻影响海洋微生物的活动，但由于专用设备的可用性有限，大多数对深海微生物群落的研究都是在大气压下进行的。与南丹麦大学的丹麦哈达尔研究中心合作，本研究将确定压力对微生物群落及其在浴场和深度质量深度的压力特征的细胞外酶的影响。在海上和实验室中，科学团队将比较抑郁症对深海微生物群落产生的酶的活性以及高压对地表水衍生酶和群落的影响。现场工作将在丹麦沿海水域，以及北大西洋开放式和太平洋。使用加压系统和原位孵育，本研究将测量肽和多糖的水解速率，这是海洋有机物的两个主要类别。项目活动还将着重于开发衡量深海中酶活性的手段。与德国Max Planck海洋微生物学研究所的同事合作，该计划将还研究压力是否会影响多糖的自私吸收。这些研究将提供有关深入研究中有机物质命运的研究的新见解。该项目由生物和化学海洋学计划提供资金。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的审查标准来通过评估来通过评估来支持的。