Collaborative Research: Genetic and Metabolic Signatures of Marine Microorganisms in Oxygen Depleted and Varying Geochemical Seascapes (MetaOmics in the Cariaco Basin)

缺氧水柱（ODWCs）似乎正在扩大，以应对全球气候变化。这改变了营养结构，压缩了栖息地，改变了主要元素的地球化学循环。从季节性缺氧到永久性缺氧，缺氧的强度和持续时间各不相同。本研究的重点是缺氧端元的一个典型例子——卡里亚科盆地。总体目标是研究微生物功能潜力（宏基因组学）、活性（宏转录组学）、分类多样性（基于SSU rRNA）和生态/地球化学后果（根据关键过程的测量速率）在卡里亚科盆地沿垂直氧/地球化学梯度和季节之间的关系。这将揭示特定基因的表达、营养物质、能量底物和氧化剂有效性的环境差异之间的关系。目标是：(1)将水文、地球化学和微生物生态数据与宏基因组和亚转录组数据相结合，以了解在高产和低生产力时期微生物群落对环境强迫响应的调节和代谢网络。这将有助于了解过程的重要性，例如甲烷的厌氧氧化，氧化还原敏感金属的利用，该ODWC中的隐硫循环以及氧气耗尽对氮转化的影响。(2)确定微生物真核生物（mEuks）和原核生物在ODWC中的关联的重要性。(3)识别指标。已知或未知功能的基因，这些基因可能与主要元素和微量气体循环有关，作为进一步生化表征和分子探针开发的目标，并使用qPCR对这些基因的关键子集和氧化还原梯度的转录物进行量化。(4)为开发利用重要元素转化和通量的表达基因来诊断自然和人类工程生态系统健康状况的监测工具提供基础。(5)将结果与最近和正在进行的其他odwc研究进行比较，以辨别这些系统的共同和独特属性。知识价值：以前对odwc的研究强调需要更多关于odwc微生物群落结构和功能的数据，特别是生物化学速率测量和其他关于群落对变化条件反应的数据。更好的海洋微生物群落和生物地球化学过程对全球气候变化响应的预测模型对于为未来的政策和管理决策提供信息至关重要。像Cariaco盆地这样的缺氧末端ODWC的数据非常需要与其他最近和正在进行的季节性枯竭沿海系统和永久枯竭深盆地和西部边界氧气最小带（OMZs）研究的数据进行比较，以构建更熟练的模型。这项研究将促进对世界范围内不断扩大的ODWCs影响的理解，超越仅基于分类多样性的评估，从而对这些环境中主要微生物群的生态学和生理学以及细菌、古细菌和微生物真核生物之间的相互作用产生新的见解。更广泛的影响：pi及其合作者将从SBU培养一名研究助理，一名博士后研究员，一名研究生和许多本科生。所有人员将接受微生物生态学和海洋学各方面的培训，重点是传统（如显微镜）和？前沿?（如宏基因组学/转录组学）技术。ppi还将涉及和风教育基金会？美国的海洋科学素养和教育项目位于马萨诸塞州的伍兹霍尔。pi将与该组织合作，利用Zephyr组织的当地船只实地考察，以及pi设计的讲座和课堂实验练习，对市中心的K-12学生进行教育。此外，该项目将对了解odwc如何影响海洋生态系统产生广泛影响，并可能影响未来的管理策略和描述海洋和大气之间C和N循环的模型。

Oxygen depleted water columns (ODWCs) appear to be expanding in response to global climate change. This alters trophic structure, compresses habitat and modifies geochemical cycles of major elements. Oxygen depletion can vary in intensity and duration from seasonal hypoxia to permanent anoxia. The focus of this study is a classic example of the anoxic end-member, the Cariaco Basin. The overall goal is to examine how microbial functional potential (metagenomic), activity (metatranscriptomic), taxonomic diversity (based on SSU rRNA) and the ecological/geochemical consequences (in terms of measured rates of key processes) relate along vertical oxygen/geochemical gradients and between seasons in the Cariaco Basin. This will reveal relationships between expression of particular sets of genes, environmental differences in nutrients, energy substrates and oxidant availabilities.The objectives are to: (1) Integrate hydrographic, geochemical and microbial ecological data with metagenomic and metatranscriptomic profiles to understand regulatory and metabolic networks defining microbial community responses to environmental forcing during high and low productivity periods. This will help to understand the importance of processes, such as anaerobic oxidation of methane, utilization of redox-sensitive metals, the cryptic sulfur cycle in this ODWC, and the impacts of oxygen depletion on nitrogen transformations. (2) Determine the importance of associations between microbial eukaryotes (mEuks) and prokaryotes in this ODWC. (3) Identify ?indicator? genes of known or unknown function that may be relevant to major elemental and trace gas cycling as targets for further biochemical characterization and molecular probe development, and quantify a key subset of these genes and transcripts across redox gradients using qPCR. (4) Provide a basis for developing monitoring tools using expressed genes indicative of important elemental transformations and fluxes for diagnosing the health status of natural and human engineered ecosystems. (5) Compare results with recent and ongoing studies of other ODWCs to discern shared and unique attributes of these systems.Intellectual Merit: Previous studies of ODWCs have underscored the need for more data on microbial community structure and functionality in ODWCs, particularly biochemical rate measurements and other data on community responses to changing conditions. Better predictive models of responses of marine microbial communities and biogeochemical processes to global climate change are essential for informing future policy and management decisions. Data from an anoxic end-member ODWC like Cariaco Basin are critically needed to compare with data from other recent and ongoing studies of seasonally-depleted coastal systems and permanently-depleted deep basin and western boundary oxygen minimum zones (OMZs) to construct more skillful models. This study will advance the understanding of impacts of expanding ODWCs around the world, moving beyond assessments based only on taxonomic diversity, to yield new insights into the ecology and physiology of major microbial groups in these environments and interactions among Bacteria, Archaea and microbial eukaryotes.Broader Impacts: The PIs and their collaborators will train one Research Associate, one postdoctoral investigator, a graduate student, and numerous undergraduates from SBU. All personnel will be trained in various aspects of microbial ecology and oceanography, with an emphasis on both traditional (e.g., microscopy) and ?cutting edge? (e.g. metagenomics/transcriptomics) techniques. The PIs will also involve the Zephyr Education Foundation?s marine science literacy and education program, located in Woods Hole, MA. The PIs will work with this organization to educate inner city K-12 students using local boat field trips organized by Zephyr, and lectures, and classroom laboratory exercises designed by the PIs. Additionally, this project will have broad implications for understanding how ODWCs affect marine ecosystems, and may influence future management strategies and models describing the cycling of C and N between the ocean and atmosphere.