Collaborative Research: Characterization of Microbial Transformations in Basement Fluids, from Genes to Geochemical Cycling

合作研究：从基因到地球化学循环的基底流体中微生物转化的表征

• 批准号: 1062006
• 负责人: Julie Huber
• 金额: $ 39.5万
• 依托单位: Marine Biological Laboratory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1062006&HistoricalAwards=false
• 关键词: Collaborative; Research; Characterization; Microbial; Transformations

Intellectual MeritCurrent estimates suggest that the volume of ocean crust capable of sustaining life is comparable in magnitude to that of the oceans. To date, there is little understanding of the composition or functional capacity of microbial communities in the sub-seafloor, or their influence on the chemistry of the oceans and subsequent consequences for global biogeochemical cycles. This project focuses on understanding the relationship between microbial communities and fluid chemistry in young crustal fluids that are responsible for the transport of energy, nutrients, and organisms in the crust. Specifically, the PIs will couple microbial activity measurements, including autotrophic carbon, nitrogen and sulfur metabolisms as well as mineral oxide reduction, with quantitative assessments of functional gene expression and geochemical transformations in basement fluids. Through a comprehensive suite of in situ and shipboard analyses, this research will yield cross-disciplinary advances in our understanding of the microbial ecology and geochemistry of the sub-seafloor biosphere. The focus of the effort is at North Pond, an isolated sediment pond located on ridge flank oceanic crust 7-8 million years old on the western side of the Mid-Atlantic Ridge. North Pond is currently the target for drilling on IODP expedition 336, during which it will be instrumented with three sub-seafloor basement observatories. The project will leverage this opportunity for targeted and distinct sampling at North Pond on two German-US research cruises to accomplish three main objectives:1. to determine if different basement fluid horizons across North Pond host distinct microbial communities and chemical milieus and the degree to which they change over a two-year post-drilling period.2. to quantify the extent of autotrophic metabolism via microbially-mediated transformations in carbon, nitrogen, and sulfur species in basement fluids at North Pond.3. to determine the extent of suspended particulate mineral oxides in basement fluids at North Pond and to characterize their role as oxidants for fluid-hosted microbial communities.Specific outcomes include quantitative assessments of microbial activity and gene expression as well as geochemical transformations. The program builds on the integrative research goals for North Pond and will provide important data for guiding the development of that and future deep biosphere research programs. Results will increase understanding of microbial life and chemistry in young oceanic crust as well as provide new insights into controls on the distribution and activity of marine microbial communities throughout the worlds oceans.Broader ImpactsThere are no data about microbial communities in ubiquitous cold, oceanic crust, the emphasis of the proposed work. This is an interdisciplinary project at the interface of microbial ecology, chemistry, and deep-sea oceanography with direct links to international and national research and educational organizations. It leverages on a long-term collaboration between the PIs and collaborators in both the US and Germany, including the recently formed NSF Science and Technology Center entitled "Center for Dark Energy Biosphere Investigations" (C-DEBI) and the NSF Research Coordination Network focused on the deep biosphere. This work on microbially mediated geochemical transformations in basement fluids is both attainable and timely, and methods development and results from this work will complement current and future microbial and geochemical investigations on the Juan de Fuca Ridge as part of both IODP and the OOI Regional Scale Node. The public outreach effort will utilize The Zephyr Education Foundation's unique marine science program to incorporate a short educational module focused on marine microbiology that will be tailored to the grade levels 7 through college. The module will emphasize the importance of marine microbes to environmental sustainability, human health, and the origin and evolution of life on our planet. The project also supports the research and career development of one graduate student, one undergraduate student, and two postdoctoral researchers. Students and postdocs will to engage with the larger community of researchers interested in deep biosphere microbiology and chemistry through emerging and existing NSF programs.

智力价值目前的估计表明，能够维持生命的洋壳的体积在大小上与海洋相当。迄今为止，对于海底以下微生物群落的组成或功能能力，或它们对海洋化学的影响以及随后对全球生物地球化学循环的影响，人们知之甚少。这个项目的重点是了解年轻地壳流体中微生物群落和流体化学之间的关系，这些流体负责地壳中的能量、营养物质和生物体的运输。具体地说，PI将结合微生物活动测量，包括自养碳、氮和硫代谢以及矿物氧化物还原，以及对基底液中功能基因表达和地球化学转化的定量评估。通过一套全面的现场和船上分析，这项研究将在我们对海底以下生物圈的微生物生态和地球化学的理解方面取得跨学科的进展。这项工作的重点是北池，这是一个孤立的沉淀池，位于大西洋中部海脊西侧的洋壳脊侧，有700万到800万年的历史。北池目前是IODP探险336号的钻探目标，在此期间，它将配备三个海底下地下室天文台。该项目将利用这一机会在两次德美研究巡航中对北池进行有针对性的不同采样，以实现三个主要目标：1.确定北池不同的基底流体是否拥有不同的微生物群落和化学环境，以及它们在钻探后两年内发生变化的程度。通过微生物介导的基底液中碳、氮和硫物种的转化来量化自养新陈代谢的程度。确定北池基底流体中悬浮颗粒矿物氧化物的程度，并表征其作为流体宿主微生物群落的氧化剂的作用。具体结果包括对微生物活动和基因表达的定量评估以及地球化学转化。该计划建立在北池综合研究目标的基础上，并将为指导该计划和未来深层生物圈研究计划的发展提供重要数据。这些结果将增加对年轻洋壳中微生物生命和化学的了解，并为控制整个世界海洋中海洋微生物群落的分布和活动提供新的见解。广泛的影响没有关于无处不在的寒冷洋壳中微生物群落的数据，这是拟议工作的重点。这是一个涉及微生物生态学、化学和深海海洋学的跨学科项目，与国际和国家研究和教育组织有直接联系。它利用了美国和德国的PIS和合作者之间的长期合作，包括最近成立的名为“暗能量生物圈调查中心”(C-DEBI)的NSF科学和技术中心，以及专注于深层生物圈的NSF研究协调网络。这项关于基底流体中微生物介导的地球化学转化的工作既是可以实现的，也是及时的，这项工作的方法开发和结果将作为IODP和OOI区域尺度节点的一部分，补充Juan de Fuca山脊目前和未来的微生物和地球化学调查。公众宣传工作将利用泽菲尔教育基金会独特的海洋科学计划，纳入一个专注于海洋微生物学的简短教育模块，该模块将根据7年级到大学的要求量身定做。该单元将强调海洋微生物对环境可持续性、人类健康以及地球上生命的起源和进化的重要性。该项目还支持一名研究生、一名本科生和两名博士后研究人员的研究和职业发展。学生和博士后将通过新兴的和现有的NSF项目，与更多对深层生物圈微生物学和化学感兴趣的研究人员接触。