Dimensions: Collaborative Research: An Integrated Study of Energy Metabolism, Carbon Fixation, and Colonization Mechanisms in Chemosynthetic Microbial Communities at Deep-Sea Vents

维度：合作研究：深海喷口化学合成微生物群落能量代谢、碳固定和定植机制的综合研究

• 批准号: 1136488
• 负责人: Ramunas Stepanauskas
• 金额: $ 41.17万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 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: 2011-10-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1136488&HistoricalAwards=false
• 关键词: Dimensions; Collaborative; Research; Integrated; Study

Deep-sea hydrothermal vents, first discovered in 1977, are poster child ecosystems where microbial chemosynthesis rather than photosynthesis is the primary source of organic carbon. Significant gaps remain in our understanding of the underlying microbiology and biogeochemistry of these fascinating ecosystems. Missing are the identification of specific microorganisms mediating critical reactions in various geothermal systems, metabolic pathways used by the microbes, rates of the catalyzed reactions, amounts of organic carbon being produced, and the larger role of these ecosystems in global biogeochemical cycles. To fill these gaps, the investigators will conduct a 3-year interdisciplinary, international hypothesis-driven research program to understand microbial processes and their quantitative importance at deep-sea vents. Specifically, the investigators will address the following objectives:1. Determine key relationships between the taxonomic, genetic and functional diversity, as well as the mechanisms of energy and carbon transfer, in deep-sea hydrothermal vent microbial communities.2. Identify the predominant metabolic pathways and thus the main energy sources driving chemoautotrophic production in high and low temperature diffuse flow vents.3. Determine energy conservation efficiency and rates of aerobic and anaerobic chemosynthetic primary productivity in high and low temperature diffuse flow vents.4. Determine gene expression patterns in diffuse-flow vent microbial communities during attachment to substrates and the development of biofilms.Integration: To address these objectives and to characterize the complexity of microbially-catalyzed processes at deep-sea vents at a qualitatively new level, we will pursue an integrated approach that couples an assessment of taxonomic diversity using cultivation-dependent and -independent approaches with methodologies that address genetic diversity, including a) metagenomics (genetic potential and diversity of community), b) single cell genomics (genetic potential and diversity of uncultured single cells), c) meta-transcriptomics and -proteomics (identification and function of active community members, realized potential of the community). To assess function and response to the environment, these approaches will be combined with 1) measurement of in situ rates of chemoautotrophic production, 2) geochemical characterization of microbial habitats, and 3) shipboard incubations under simulated in situ conditions (hypothesis testing under controlled physicochemical conditions). Network approaches and mathematical simulation will be used to reconstruct the metabolic network of the natural communities. A 3-day long project meeting towards the end of the second year will take place in Woods Hole. This Data Integration and Synthesis meeting will allow for progress reports and presentations from each PI, postdoc, and/or student, with the aim of synthesizing data generated to facilitate the preparation of manuscripts.Intellectual Merit. Combining the community expression profile with diversity and metagenomic analyses as well as process and habitat characterization will be unique to hydrothermal vent microbiology. The approach will provide new insights into the functioning of deep-sea vent microbial communities and the constraints regulating the interactions between the microbes and their abiotic and biotic environment, ultimately enabling us to put these systems into a quantitative framework and thus a larger global context.Broader Impacts. This is an interdisciplinary and collaborative effort between 4 US and 4 foreign institutions, creating unique opportunities for networking and fostering international collaborations. This will also benefit the involved students (2 graduate, several undergraduate) and 2 postdoctoral associates. This project will directly contribute to many educational and public outreach activities of the involved PIs, including the WHOI Dive & Discover program; single cell genomics workshops and Cafe Scientifique (Bigelow); REU (WHOI, Bigelow, CIW); COSEE and RIOS (Rutgers), and others. The proposed research fits with the focus of a number of multidisciplinary and international initiatives, in which PIs are active members (SCOR working group on Hydrothermal energy and the ocean carbon cycle, http://www.scorint. org/Working_Groups/wg135.htm; Deep Carbon Observatory at CIW, https://dco.gl.ciw.edu/; Global Biogeochemical Flux (GBF) component of the Ocean Observatories Initiative (OOI), http://www.whoi.edu/GBF-OOI/page.do?pid=41475)

1977年首次发现的深海热液喷口是典型的生态系统，其中微生物化学合成而不是光合作用是有机碳的主要来源。在我们对这些迷人生态系统的潜在微生物学和生物地球化学的理解方面仍然存在重大差距。缺少的是在各种地热系统中介导关键反应的特定微生物的识别，微生物使用的代谢途径，催化反应的速率，产生的有机碳的量，以及这些生态系统在全球地球化学循环中的更大作用。为了填补这些空白，研究人员将进行一项为期3年的跨学科、国际假设驱动的研究计划，以了解微生物过程及其在深海喷口的定量重要性。具体而言，研究人员将解决以下目标：1。确定深海热液喷口微生物群落的分类、遗传和功能多样性以及能量和碳转移机制之间的关键关系。确定主要的代谢途径，从而在高低温扩散流孔中驱动化能自养生产的主要能量来源。测定了高、低温扩散流通风口的节能效率和好氧、厌氧化学合成初级生产力率.确定扩散流喷口微生物群落在附着于基质和形成生物膜过程中的基因表达模式。为了实现这些目标，并在质量上达到新的水平，说明深海喷口微生物催化过程的复杂性，我们将采取综合方法，结合利用依赖于栽培的分类多样性评估和-处理遗传多样性的独立方法，包括a）宏基因组学（群落的遗传潜力和多样性），B）单细胞基因组学（未培养的单细胞的遗传潜力和多样性），c）元转录组学和蛋白质组学（社区活跃成员的识别和功能，社区实现的潜力）。为了评估功能和对环境的响应，这些方法将与1）化学自养生产的原位速率测量，2）微生物栖息地的地球化学表征，以及3）模拟原位条件下的船上培养（在受控物理化学条件下的假设检验）相结合。利用网络方法和数学模拟方法，重建自然群落的代谢网络。第二年年底将在伍兹霍尔举行为期3天的项目会议。本次数据集成和综合会议将允许每个PI，博士后和/或学生的进度报告和演示文稿，目的是综合生成的数据，以促进手稿的准备。将群落表达谱与多样性和宏基因组分析以及过程和生境特征描述相结合，将是热液喷口微生物学的独特之处。该方法将为深海喷口微生物群落的功能以及调节微生物与其非生物和生物环境之间相互作用的制约因素提供新的见解，最终使我们能够将这些系统纳入定量框架，从而纳入更大的全球范围。这是4个美国和4个外国机构之间的跨学科和合作努力，为建立网络和促进国际合作创造了独特的机会。这也将有利于参与的学生（2名研究生，几名本科生）和2名博士后助理。该项目将直接促进相关PI的许多教育和公共宣传活动，包括WHOI Dive Discover计划;单细胞基因组学研讨会和Cafe Scientific（Bigelow）; REU（WHOI，Bigelow，CIW）; COSEE和RIOS（Rutgers）等。拟议的研究符合一些多学科和国际倡议的重点，其中PI是积极的成员（SCOR热液能源和海洋碳循环工作组，http://www.scorint）。org/Working_Groups/wg135.htm; CIW的深层碳观测站，https：//dco.gl.ciw.edu/;海洋观测站倡议（OOI）的全球生物地球化学通量（GBF）组成部分，http://www.whoi.edu/GBF-OOI/page.do? pid=41475）