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动沉积物主要由新的微生物群落主导，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。该项目将调查瓜伊马斯沉积物中主要未培养生物的基因组潜力、生理能力和生物地球化学作用，特别是专门出现在热液活动沉积物(ANME-1瓜伊马斯)中的高温厌氧甲烷氧化菌。这项研究将重点放在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。一级研究课题包括量化高温下的厌氧甲烷氧化、原位磷和甲烷浓度以及替代电子受体；在这些条件下依赖硫酸盐和硫的微生物途径和同位素特征；以及甲烷氧化微生物群落、热液垫子和沉积物中的氮转化。智力价值：这项综合的生物地球化学和微生物学研究将探索甲烷、其他烷烃、无机碳、有机酸和有机质的消费和生产的途径和环境控制，这些物质是瓜伊马斯沉积微生物生态系统的燃料。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一个空间紧凑、高活性的地点。在厌氧甲烷氧化的情况下，瓜伊马斯盆地甲烷氧化微生物群落的高温和压力耐受性，以及它们与主要电子受体硫酸盐解偶联的潜力，极大地增加了全球深层地下成岩作用中厌氧微生物甲烷营养的预计地下栖息地空间和生物地球化学作用。此外，微生物甲烷的产生和氧化与硫磺和氮的转化相互作用，这将在生物和过程一级在瓜伊马斯盆地的热液沉积物微生物群落和垫子中进行探索。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)确定了在地下热液/渗漏与深海水之间进行化学交换的关键微生物能力、途径和过程。更广泛的影响：西菲尔教育基金会将与其独特的海洋科学素养和教育计划合作，设计一项教育实地练习。该基金会位于伍兹霍尔，协调学校班级的实地考察，包括参与实践学习和在水上和实验室中的发现。这项研究的问题、技术和相关性将以一种促进认识和理解的方式提出。沉积物取心、沿海沉积物与瓜伊马斯盆地原始样本材料的比较，以及说明海底测绘挑战的侧扫声纳演示(这是热液喷口研究中的一个非常现实的问题)，将作为Zephy Foundation 40英尺长的RV Minuteman号海上课程旅行的一部分，在伍兹霍尔沿海水域进行。基金会将把这一单元作为他们每年向大约1 000名学生和他们的老师提供的船上亲身实践海洋科学实地考察系列的一部分。这一外联构成部分扩大了各警察与西风领导的外联活动之间的持续协作。在北卡罗来纳州大学本科生一级的教学和参与课程(为所有领域的新生举办的极端微生物研讨会，以及为初级/高级理科专业学生举办的海洋学入门课程)中，被广泛用于教学和参与课程的每日巡游博客，由公社为最近的三次亚特兰蒂斯号/阿尔文号邮轮撰写、插图和张贴。PI将为下一次瓜伊马斯盆地邮轮写一篇每日邮轮博客，并在海上制作简短(3分钟)的视频，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.