Collaborative Research: Influence of pressure on microbial communities in subseafloor sediment at hadal, abyssal, bathyal, and shelf water depths

合作研究：压力对深渊、深海、深海和陆架水深海底沉积物中微生物群落的影响

• 批准号: 2048927
• 负责人: Douglas Bartlett
• 金额: $ 61.69万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2048927&HistoricalAwards=false
• 关键词: Collaborative; Research; Influence; pressure; microbial

The globe-spanning realm of subseafloor sediment is Earth’s least-explored large biome. This project addresses a fundamental question about the microbial communities that inhabit the subseafloor sedimentary environment – to what extent and in what ways are they adapted to the low temperature, high pressure conditions where they are found? Or, alternatively, are they just accidentally introduced from the shallower and lower-pressure world where the organic matter that feeds them largely originates? This project is examining how these organisms metabolize organic matter in sediments. The project is also advancing the development of a diverse, globally competitive workforce in science, technology, engineering, and mathematics (STEM). It introduces 10 or more students to sea-going research, by including them as shipboard scientists. The project especially focusses on creating and funding opportunities for students from minority groups under-represented in STEM fields, students from economically disadvantaged backgrounds, and students from Puerto Rico, and from multiple educational stages (ranging from community college to graduate school), with diverse STEM interests. Study of samples and data from the expedition are central to graduate and undergraduate research by students from these multiple institutions. The project also supports the broader science community by collecting and providing diverse samples for additional studies, including, but not limited to, studies of deep-water residence time in a deep-sea trench, past oceanographic conditions, and subseafloor microbes. The fundamental objective of this project is to determine how the subseafloor microbial communities and activities across a gradient of oceanic depth zones (sublittoral, bathyal, abyssal, hadal) are impacted by the pressure of the surrounding water. The primary hypothesis being tested is that “microbial communities in subseafloor sediment are adapted for in situ pressure.” The null hypothesis is that these “communities are merely remnant populations introduced from shallower depths and poorly adapted for in situ pressure.” To test these hypotheses, the project compares the subseafloor communities and rates of activity that occur in anoxic subseafloor sediment at ocean depths ranging from 50 to ~8400 meters below sea level in the Puerto Rico Trench region. To collect the samples and shipboard data, the project includes a 26-day coring program. The project interrogates the genomic composition and community metabolic rates of the subseafloor sedimentary communities over this full range of ocean depths. Experiments are being conducted to determine the pressure-dependence of potential processes (sulfate reduction and methanogenesis) and genes that are preferentially expressed at in situ pressures by sublittoral, bathyal, abyssal and hadal subseafloor communities. These results are synthesized to identify the nature and extent of adaptations to in situ pressure in subseafloor communities.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.

地球沉积物的全球跨度域是地球最少的大生物群落。该项目解决了继承亚基沉积环境的微生物群落的一个基本问题 - 它们在何种程度，以何种方式适应了发现它们的低温，高压条件？或者，另外，它们是否只是从较浅和低压的世界中意外引入的，在这些世界中，有机物在很大程度上起源？该项目正在研究这些生物如何代谢沉积物中的有机物。该项目还正在推进科学，技术，工程和数学（STEM）多样性，全球竞争劳动力的发展。它通过将他们作为船上科学家（包括他们）介绍了10个或更多的学生进行海上研究。该项目尤其着重于为来自STEM领域中少数群体的学生创造和资助机会，来自经济弱势背景的学生以及来自波多黎各的学生以及来自多个教育阶段（从社区学院到研究生院的多个教育阶段），具有潜水员STEM兴趣的学生。这些探险的样本和数据的研究至关重要，是这些多个机构的学生的研究生和本科研究。该项目还通过收集和提供潜水员样本进行其他研究来支持更广泛的科学界，包括但不限于深水沟渠中的深水停留时间，过去的海洋学状况和次生层微生物的研究。该项目的基本目标是确定海洋深度区域（Sublitoral，Bathyal，Abyssal，Hadal，Hadal）的子层面微生物群落和活动如何受到周围水压力的影响。测试的主要假设是“微生物”。零假设是“这些社区仅是从较浅的深度引入的残余人群，并且适应不良的原位压力。”为了检验这些假设，该项目比较了在波多黎各沟槽地区海拔50至〜8400米之间的海洋深处的缺氧亚铁矿沉积物中发生的亚基群落和活动率。收集样品和船上数据，该项目包括一个26天的加油计划。该项目询问了整个海洋深度范围内，质疑子层沉积社区的基因组成分和社区代谢率。正在进行实验，以确定潜在过程（硫酸盐还原和甲烷生成）的压力依赖性以及优选地通过Sublitoral，Bathyal，Abyssal和Hadal supeafloor社区表达的基因。合成这些结果是为了确定适应于亚基群社区的原位压力的性质和程度。该奖项反映了NSF的法定使命，并使用基金会的知识分子优点和更广泛的影响来评估，被认为是宝贵的支持。