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

概述：瓜伊马斯盆地的热液活跃沉积物以新型微生物群落为主，这些微生物群落在这些海底生态系统中催化重要的生物地球化学过程。本项目将研究Guaymas沉积物中关键非培养生物的基因组潜力、生理能力和生物地球化学作用，特别是存在于热液活性沉积物（ANME-1Guaymas）中的高温厌氧甲烷氧化剂。这项研究将集中在它们在碳转化中的作用，但也探索它们在硫和氮转化中的潜在参与。一级研究课题包括量化高温下厌氧甲烷氧化，原位磷和甲烷浓度，以及替代电子受体；在这些条件下硫酸盐和硫依赖的微生物途径和同位素特征；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：这项综合生物地球化学和微生物学研究将探索为瓜伊马斯沉积微生物生态系统提供燃料的甲烷、其他烷烃、无机碳、有机酸和有机物的消耗和生产的途径和环境控制。瓜伊马斯盆地热液沉积物为研究甲烷循环和碳同化到微生物生物量的新模式提供了一个空间紧凑、高活性的地点。在厌氧甲烷氧化的情况下，瓜依马斯盆地甲烷氧化微生物群落的高温高压耐受性，以及它们与主要电子受体硫酸盐解耦的潜力，极大地增加了预测的地下栖息地空间和厌氧微生物甲烷化在全球深层地下成岩作用中的生物地球化学作用。此外，Guaymas盆地热液沉积物微生物群落和地垫的微生物甲烷生产和氧化与硫和氮转化互锁，将在生物和过程水平上进行探索。一般来说，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）确定了调节地下热液/渗漏与深海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：拥有独特海洋科学素养和教育项目的Zephyr教育基金会将合作设计一个教育领域的练习。该基金会位于伍兹霍尔（Woods Hole），负责协调学校班级的实地考察，包括参与水上和实验室的实践学习和发现。本研究的问题、技术和相关性将以促进认识和理解的方式呈现。沉积物取芯，沿海沉积物与原始瓜伊马斯盆地样品材料的比较，以及侧面扫描声纳演示，说明海底测绘的挑战（热液喷口研究中的一个非常现实的问题），将作为Zephyr基金会40英尺船RV Minuteman在伍兹霍尔沿海水域进行的海上旅行的一部分。基金会将把这个单元作为他们的船上实践海洋科学实地考察系列的一部分，每年向大约1000名学生和他们的老师提供。这一外展组成部分扩大了pi与zephyr领导的外展活动之间正在进行的合作。由PI为最近的三次亚特兰蒂斯/阿尔文游轮撰写、插图和发布的日常邮轮博客被广泛用于北卡罗来纳大学本科生的教学和参与课程（针对所有领域的新生的极端微生物研讨会，以及针对大三/大四科学专业的海洋学导论）。PI将为下一次瓜伊马斯盆地的航行撰写每日的航行博客，并制作简短（3分钟）的海上视频，供网站和课堂使用。

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.