Collaborative Research: ETBC: Deep Crustal Biosphere: Microbial Cycling of Carbon

合作研究：ETBC：深地壳生物圈：碳的微生物循环

• 批准号: 0948659
• 负责人: Tullis Onstott
• 金额: $ 46.65万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0948659&HistoricalAwards=false
• 关键词: Collaborative; Research; ETBC; Deep; Crustal

Intellectual Merit. For the past two decades studies from around the world in a wide variety of geological environments in both continental and marine settings have revealed the extent and variety of subsurface microbial ecosystems. From polar permafrost and ice sheets to equatorial marine sediments, from permeable aquifers ~200 meters deep to fractured rock 4 km deep, from deep vadose zones to oil reservoirs, diverse assemblages of bacteria and archaea, including many novel species, have been discovered. As depth and temperature increase in both the continental and oceanic crust, the effects of changing surface climate and photospheric processes on the subsurface microbial ecosystem diminish while Fisher-Tropsch-like and radiolytic processes, which enrich the crust with a mixture of organic and inorganic nutrients, become increasingly important. Regardless of the origin of the organic carbon, the rules that govern its biodegradation to CO2 and CH4 should be similar to those for petroleum reservoirs. The goals of this project are to determine those rules, determine the rates and limits of the biodegradation of organic matter by subsurface microbial ecosystems, and determine who is responsible. To accomplish these goals, investigators will utilize the readily accessible boreholes present in the mines of the Witwatersrand Basin, South Africa, which range in depth from 0.8 to 3.8 km, to examine the extent of and the inter-species interactions involved in biodegradation of organic photosynthate in shallow depths and abiogenic hydrocarbons at great depth. By employing a combination of 1) GCMS, HPLC, and NMR characterization of the DOC, 2) 13C analyses of DOC, DIC, hydrocarbons, lipids, and organic acids, 3) H isotope analyses of hydrocarbons, 4) 14C analyses of CH4, DIC, DOC, and lipids, and 5) stable isotope probes (SIP) of the 16S rRNA, we will delineate the relative importance of 1) chemoautotrophically produced organic acids, 2) abiogenically produced hydrocarbons, 3) thermogenically produced organic acids and 4) dissolved organic matter (DOC) from the surface photosphere, to the subsurface microbial community structure and its trophic interactions during carbon metabolism. These analyses will be performed on planktonic microbial communities collected from fracture water ranging in age from thousands of years to tens of millions of years. Broader Impacts. The program of study will engage undergraduates and graduates in hands-on interdisciplinary research where they will integrate isotope geochemistry and organic geochemical analyses with genetic analyses. Students from North America and South Africa will participate in the field and laboratory research as part of an ongoing collaboration with South African scientists. The RNA-SIP incubation experiments will be accompanied by isolation experiments that will further enlarge the subsurface culture collection and genetic database at the Univ. of Free State (UFS) and enhance their bioremediation and biotechnology efforts. The project will begin to integrate the genetic, taxonomic and functional diversity with respect to carbon metabolism. Investigators will work to assemble a web-based subsurface microbial database with a gallery of SEM/TEM images of subsurface microorganisms that can be downloaded for press releases; and as part of the gallery we will initiate a "Where in the world does this organism occur?" describing where related strains or sequences have been found. The web site will provide the beginnings of a microbial biogeographical database for the deep subsurface. When permitted by the mining companies videos of the sampling expeditions will be posted on the web site. The project will also provide fundamental scientific underpinnings for optimal exploitation of untapped natural gas reservoirs in the Witwatersrand Basin and for the development of CO2 sequestration projects in South Africa by private firms

智力优势。 在过去的二十年里，世界各地在大陆和海洋环境中各种地质环境中的研究揭示了地下微生物生态系统的范围和多样性。 从极地永久冻土和冰盖到赤道海洋沉积物，从200米深的渗透性含水层到4公里深的断裂岩石，从深层渗流带到油藏，发现了细菌和古菌的多样组合，包括许多新物种。 随着大陆和海洋地壳深度和温度的增加，地表气候变化和光球过程对地下微生物生态系统的影响逐渐减弱，而使地壳富含有机和无机营养物的类费托和辐解过程变得越来越重要。 无论有机碳的来源如何，其生物降解为CO2和CH 4的规则应该与石油储层的规则相似。 该项目的目标是确定这些规则，确定地下微生物生态系统对有机物生物降解的速率和限制，并确定谁负责。为了实现这些目标，调查人员将利用南非威特沃特斯兰德盆地矿区现有的、深度从0.8公里到3.8公里的、容易进入的钻孔，研究浅层有机光生物降解和深层非生物成因碳氢化合物生物降解的程度和物种间相互作用。 通过采用1）DOC的GCMS、HPLC和NMR表征，2）DOC、DIC、烃、脂质和有机酸的13 C分析，3）烃的H同位素分析，4）CH 4、DIC、DOC和脂质的14 C分析，和5）16 S rRNA的稳定同位素探针（SIP）的组合，我们将描述1）化能自养产生的有机酸，2）非生物产生的烃，3）生热产生的有机酸和4）来自表面光球的溶解有机物（DOC）的相对重要性，地下微生物群落结构及其在碳代谢过程中的营养相互作用。 这些分析将对从断裂水中收集的微生物群落进行，年龄从数千年到数千万年不等。 更广泛的影响。该研究计划将使本科生和研究生参与动手跨学科研究，将同位素地球化学和有机地球化学分析与遗传分析相结合。 来自北美和南非的学生将参与实地和实验室研究，作为与南非科学家持续合作的一部分。 RNA-SIP孵育实验将伴随着分离实验，这将进一步扩大自由州大学（UFS）的地下培养物收集和遗传数据库，并加强他们的生物修复和生物技术工作。 该项目将开始整合碳代谢方面的遗传、分类和功能多样性。调查人员将致力于建立一个基于网络的地下微生物数据库，其中包含一个可以下载用于新闻发布的地下微生物SEM/TEM图像库;作为该图像库的一部分，我们将发起一个“这种生物体在世界上哪里出现？该网站将提供深层地下微生物地理数据库的开端。 在采矿公司允许的情况下，取样考察的录像将张贴在网站上。 该项目还将为威特沃特斯兰德盆地未开发天然气储藏的最佳开采和私营公司在南非开发二氧化碳封存项目提供基本的科学依据