Collaborative Research: Microbial Carbon cycling and its interactions with Sulfur and Nitrogen transformations in Guaymas Basin hydrothermal sediments

概述：在瓜伊马斯盆地的热液活动沉积物中占主导地位的新型微生物群落，催化这些海底生态系统中的重要地球化学过程。本项目将研究瓜伊马斯沉积物中关键未培养生物的基因组潜能、生理能力和生物地球化学作用，特别是热液活性沉积物中特有的高温厌氧甲烷氧化剂（ANME-1瓜伊马斯）。该研究将重点关注它们在碳转化中的作用，但也将探索它们在硫和氮转化中的潜在参与。一阶研究课题包括量化高温下厌氧甲烷氧化，原位浓度的磷和甲烷，并与备用电子受体;硫酸盐和硫依赖的微生物途径和同位素特征在这些条件下;和甲烷氧化微生物群落，热液垫和沉积物中的氮转化。智力优势：这一综合地球化学和微生物研究将探索甲烷、其他烷烃、无机碳、有机酸和有机物质的消费和生产途径和环境控制，这些物质为瓜伊马斯沉积微生物生态系统提供燃料。瓜伊马斯盆地的热液沉积物为研究甲烷循环和碳同化为微生物生物量的新模式提供了空间紧凑、高活性的位置。在厌氧甲烷氧化的情况下，高温和高压耐受性的瓜伊马斯盆地甲烷氧化微生物群落，和他们的潜力，从占主导地位的电子受体硫酸盐解偶联，大大增加了预测的地下栖息地空间和地球化学作用厌氧微生物甲烷营养在全球深部地下成岩作用。此外，微生物甲烷的产生和氧化与硫和氮的转化相互关联，这将在生物和过程水平上探索瓜伊马斯盆地热液沉积物微生物群落和席。一般而言，一级研究任务（速率测量、放射性示踪剂掺入研究、基因组、原位微梯度）确定了介导地下热液/渗漏与深海沃茨之间化学交换的关键微生物能力、途径和过程。更广泛的影响：Zephyr教育基金会及其独特的海洋科学素养和教育计划将合作设计一项教育实地演习。该基金会位于伍兹霍尔，并协调学校班级的实地考察，包括参与动手学习和发现的水和实验室。本研究的问题，技术和相关性将以促进认识和理解的方式提出。将在伍兹霍尔沿海沃茨，利用Zephyr基金会40英尺长的RV Minuteman船进行航海类旅行，其中包括沉积物取芯、沿海沉积物与原始瓜伊马斯盆地样本材料的比较以及侧扫声纳演示，以说明海底测绘的挑战（热液喷口研究中一个非常真实的问题）。该基金会将介绍这个单元作为他们的船上，动手海洋科学实地考察系列的一部分，每年提供给大约1 000名学生和他们的老师。这一外联部分扩大了PI与Zephyr领导的外联活动的持续合作。每日巡航博客，写的，说明和最近三个亚特兰蒂斯/阿尔文邮轮PI张贴被广泛用于教学和从事类在亚特兰蒂斯大学本科水平（极端微生物研讨会为所有领域的新生，和介绍海洋学为初级/高级科学专业）。PI将为下一次瓜伊马斯盆地巡航撰写每日巡航博客，并在海上制作简短（3分钟）视频，供网站发布和课堂使用。

Overview: Hydrothermally active sediments in the Guaymas Basin are dominated by novel microbial communities that catalyze important biogeochemical processes in these seafloor ecosystems. This project will investigate genomic potential, physiological capabilities and biogeochemical roles of key uncultured organisms from Guaymas sediments, especially the high-temperature anaerobic methane oxidizers that occur specifically in hydrothermally active sediments (ANME-1Guaymas). The study will focus on their role in carbon transformations, but also explore their potential involvement in sulfur and nitrogen transformations. First-order research topics include quantifying anaerobic methane oxidation under high temperature,in situ concentrations of phosphorus and methane , and with alternate electron acceptors; sulfate and sulfur-dependent microbial pathways and isotopic signatures under these conditions; and nitrogen transformations in methane-oxidizing microbial communities, hydrothermal mats and sediments. Intellectual Merit: This integrated biogeochemical and microbiological research will explore the pathways of and environmental controls on the consumption and production of methane, other alkanes, inorganic carbon, organic acids and organic matter that fuel the Guaymas sedimentary microbial ecosystem. The hydrothermal sediments of Guaymas Basin provide a spatially compact, high-activity location for investigating novel modes of methane cycling and carbon assimilation into microbial biomass. In the case of anaerobic methane oxidation, the high temperature and pressure tolerance of Guaymas Basin methane-oxidizing microbial communities, and their potential to uncouple from the dominant electron acceptor sulfate, vastly increase the predicted subsurface habitat space and biogeochemical role for anaerobic microbial methanotrophy in global deep subsurface diagenesis. Further, microbial methane production and oxidation interlocks with syulfur and nitrogen transformations, which will be explored at the organism and process level in hydrothermal sediment microbial communities and mats of Guaymas Basin. In general, first-order research tasks (rate measurements, radiotracer incorporation studies, genomes, in situ microgradients) define the key microbial capabilities, pathways and processes that mediate chemical exchange between the subsurface hydrothermal/seeps and deep ocean waters. Broader Impacts: The Zephyr Education Foundation, with its unique marine science literacy and education program will collaborate in the design of an educational field exercise. The Foundation is located in Woods Hole and coordinates school class field trips that include participating in hands-on learning and discovery on the water and in the laboratory. The questions, techniques, and relevance of this research will be presented in a manner that promotes awareness and understanding. Sediment coring, comparisons of coastal sediments to original Guaymas Basin sample materials, and side scan sonar demos that illustrate the challenges of sea floor mapping (a very real problem in hydrothermal vent research) will be performed as part of seagoing class trips with the Zephyr Foundation 40-foot boat RV Minuteman in the coastal waters of Woods Hole. The Foundation will present this unit as part of their on-board, hands-on marine science field trip series that is delivered to approximately 1,000 students and their teachers per year. This outreach component expands the ongoing collaboration of the PIs with Zephyr-led outreach activities. Day-by-day cruise blogs, written, illustrated and posted by the PI for three recent Atlantis/Alvin cruises are used extensively for teaching and engaging classes at UNC at the undergraduate level (Extreme microbes seminar for freshmen of all fields, and Introduction to Oceanography for junior/senior science majors). The PI will write a daily cruise blog for the next Guaymas Basin cruise and make short (3 min) videos at sea for web site posting and classroom use.