Collaborative Research: Microbially Mediated Anaerobic Carbon Cycling in Limnologically Contrasting Perennially Ice-Covered Antarctic Lakes

合作研究：湖泊常年冰雪覆盖的南极湖泊中微生物介导的厌氧碳循环

• 批准号: 0739516
• 负责人: Samantha Joye
• 金额: $ 53.93万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0739516&HistoricalAwards=false
• 关键词: Collaborative; Research; Microbially; Mediated; Anaerobic

Intellectual Merit: Anaerobic microbial processes mediate organic carbon mineralization in anoxic soils, sediments, and aquatic systems. The lakes of the McMurdo Dry Valleys (MCM) are perennially ice-covered and are the primary refuge for life in this hyperarid polar desert. The focus of the proposed research is on anaerobic microbially mediated carbon cycling in the bottom water and sediments of two geochemically contrasting Dry Valley lakes, Fryxell (FRX) and Vanda (VAN). Previous studies and preliminary data indicate that the key anaerobic processes of sulfate reduction and methanogenesis are distinct these lakes. In VAN, anaerobic metabolism is dominated by sulfate reduction while methanogenesis dominates in FRX. The research plan will study in detail a globally relevant biogeochemical process, the anaerobic oxidation of methane (AOM), which is almost certainly supported by a metabolically novel mechanism in FRX; the potential for AOM in Lake Vanda is unknown. The research program will address the following overarching questions: What factors control terminal carbon metabolism in anoxic and highly stable polar lake waters and sediments? What novel microbial communities are responsible for AOM and which electron acceptor(s) support AOM in these unique lakes? Specifically, the work will determine (1) The rates and/or mechanisms of anaerobic carbon and sulfur cycling in anoxic bottom waters and sediments; (2) The role of sulfate in driving anaerobic carbon/sulfur cycling in FRX and VAN; (3) The mechanism of AOM in the anoxic sulfate-depleted bottom waters and sediments of FRX; (4) The existence and mechanism of AOM in the sulfate-rich bottom waters and sediments of VAN; (5) The identity and diversity of the microorganisms involved in AOM and other methane- and sulfur-cycling processes in these lakes. Broader Impacts: The project will employ post-doctoral, graduate, and undergraduate students, and will complement existing NSF-funded projects, the MCM Long Term Ecological Research (LTER) and Microbial Observatory (MO) projects. The PIs will provide a focused, hands-on research experience in biogeochemistry and microbiology to students and staff while simultaneously advancing our understanding of microbiology and biogeochemistry in perennially ice covered lakes. Data distribution and outreach will be accomplished via a dedicated web site linked to the PI's home page and to the MCM LTER web site, press releases, presentations at national and international conferences, and publication in peer-reviewed

智力优点：厌氧微生物过程介导缺氧土壤，沉积物和水生系统中的有机碳矿化。 McMurdo Dry Valleys（MCM）的湖泊长期覆盖，并且是这个超果层荒漠沙漠中生命的主要避难所。拟议的研究的重点是厌氧微生物介导的碳循环在底部水和两个地球化学对比的干山谷湖泊，Fryxell（FRX）和Vanda（Van）的沉积物中。先前的研究和初步数据表明，硫酸盐还原和甲烷生成的关键厌氧过程与这些湖泊不同。在VAN中，厌氧代谢以硫酸盐的减少为主，而甲烷发生在FRX中占主导地位。该研究计划将详细研究全球相关的生物地球化学过程，即甲烷（AOM）的厌氧氧化，几乎可以肯定地得到了FRX中新陈代谢新颖的机制的支持； Vanda湖的AOM潜力尚不清楚。该研究计划将解决以下总体问题：哪些因素控制终末碳代谢中的氧化湖水和沉积物中的终末碳代谢？哪些新型的微生物群落负责AOM，哪些电子受体在这些独特的湖泊中支持AOM？具体而言，这项工作将确定（1）在缺氧底部水和沉积物中厌氧碳和硫循环的速率和/或机制； （2）硫酸盐在FRX和VAN中驱动厌氧碳/硫的循环中的作用； （3）AOM在硫酸盐耗尽的底部水和FRX沉积物中的机制； （4）富含硫酸盐的底部水和货车沉积物中AOM的存在和机制； （5）这些湖泊中涉及AOM和其他甲烷和硫酸周期过程的微生物的身份和多样性。更广泛的影响：该项目将采用博士后，研究生和本科生，并将补充现有的NSF资助项目，MCM长期生态研究（LTER）和微生物天文台（MO）项目。 PIS将为学生和员工提供专注的，动手的生物地球化学和微生物学研究经验，同时促进我们对多年生冰覆盖湖泊中微生物学和生物地球化学的理解。数据分配和外展活动将通过链接到PI主页的专用网站以及MCM LTER网站，新闻稿，国家和国际会议的演讲以及同行评审的出版物来完成。