Collaborative Research: Genome-enabled Investigation of S(0) Cycling in a Subterranean Microbial Ecosystem

合作研究：地下微生物生态系统中 S(0) 循环的基因组研究

• 批准号: 1252128
• 负责人: Jennifer Macalady
• 金额: $ 30万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1252128&HistoricalAwards=false
• 关键词: Collaborative; Research; Genome; enabled; Investigation

Microbial-mineral interactions are ubiquitous and crucial aspects of geochemical cycling at the Earth's surface. Significant progress has been made towards identifying how specific groups of microorganisms interact with minerals, especially Fe oxides. However, there has been little work on how microbes make and break elemental sulfur (S(0)), though geologists have postulated microbial involvement in producing economic S(0) deposits. Chemical and biological controls on this process are not well understood, and will require a better understanding of factors affecting S(0) production and consumption within microbial biofilms.Sulfur-cycling in the deep subsurface Frasassi cave system has been the target of several previous investigations due to its unique biogeochemistry and relative accessibility to human exploration. The cave ecosystem is sustained by microbial chemosynthesis taking place near the surface of its perenially sulfidic and microoxic aquifer. Conspicuous white biofilms in the cave waters contain 20 to 80% elemental sulfur by mass. Thus its geochemical and microbiological features make Frasassi a promising system for investigating microbial interactions with S(0), an important solid-phase intermediate in the sulfur cycle. Enigmatic Epsilonproteobacteria from the globally distributed and largely uncultivated Sulfurovumales clade are major players in Frassasi biofilms. They are especially abundant in waters with high sulfide and low oxygen supply, conditions which should lead to S(0) accumulation due to limited availability of electron acceptors. Using Frasassi biofilms and enrichment cultures as a model system, investigators are combining metatranscriptomics, correlative electron microscopy, and geochemistry with field and laboratory experiments to develop new understanding of S(0)-accumulating biofilm communities. This research will improve understanding of (i) the microbial role in producing geologic S(0) deposits; (ii) mechanisms for microbial interactions with solid phase S(0); and (iii) the metabolic capabilities of currently uncultured Epsilonproteobacteria. The research supports the long-term goal of integrating genetic and geochemical understanding of modern and ancient S biogeochemistry.Project funds provide for the mentoring of two graduate students and a postdoctoral scholar. The proposed project provides outstanding opportunities for outreach to the general public due to interest in caves and extreme microbes. Images and microbial cultures from the project will be utilized in two highly successful annual events: PSU Exploration Day and PSU Geosciences Dept. "Shake, Rattle, Rocks". These events reach more than 2000 K-12 students and parents last year and 150 third grade students. Project microslide cultures will be incorporated into a hands-on grade 6-12 teacher workshop and the College of Earth, Ocean and Environment's annual Coast Day on the Lewes campus, a 34-year tradition that now attracts thousands of community members. Results will also be shared as part of the DE Sea Grant At Sea newsletter, and Sea Talk radio segments on NPR.

微生物-矿物相互作用是地球表面地球化学循环的普遍和关键方面。在确定特定微生物群体如何与矿物质，特别是氧化铁相互作用方面取得了重大进展。然而，关于微生物如何制造和破坏元素硫（S（0））的研究很少，尽管地质学家已经假设微生物参与生产经济的S（0）矿床。对这一过程的化学和生物控制尚不清楚，需要更好地了解影响微生物生物膜内S（0）产生和消耗的因素。由于其独特的地球化学和人类勘探的相对可及性，深层地下Frasassi洞穴系统中的硫循环一直是以前几次调查的目标。洞穴生态系统是由微生物化学合成维持的，这些化学合成发生在其常年含硫和微氧含水层的表面附近。洞穴沃茨中明显的白色生物膜含有20至80%的元素硫。因此，它的地球化学和微生物的特点，使Frasassi一个有前途的系统，研究微生物与S（0），一个重要的固相中间硫循环的相互作用。来自全球分布且大部分未被培养的Sulfurovumales分支的神秘Epsilonproteobacteria是Frassasi生物膜的主要参与者。它们在高硫化物和低氧供应的沃茨中特别丰富，由于电子受体的可用性有限，这些条件应导致S（0）积累。使用Frasassi生物膜和富集培养物作为模型系统，研究人员将元转录组学，相关电子显微镜和地球化学与现场和实验室实验相结合，以发展对S（0）积累生物膜群落的新认识。这项研究将提高对以下问题的理解：（i）微生物在产生地质S（0）矿床中的作用;（ii）微生物与固相S（0）相互作用的机制;以及（iii）目前未培养的Epsilonproteobacteria的代谢能力。该研究支持整合现代和古代地球化学的遗传和地球化学理解的长期目标。项目资金为两名研究生和一名博士后学者提供指导。由于对洞穴和极端微生物的兴趣，拟议的项目为向公众宣传提供了极好的机会。该项目的图像和微生物培养物将用于两个非常成功的年度活动：PSU勘探日和PSU地球科学部。“摇，摇，摇”去年，这些活动覆盖了2000多名K-12学生和家长以及150名三年级学生。项目显微镜培养将被纳入一个动手6-12年级教师研讨会和地球，海洋和环境学院的年度海岸日在刘易斯校园，一个34年的传统，现在吸引了成千上万的社区成员。研究结果也将作为DE Sea Grant At Sea时事通讯和NPR上的Sea Talk广播片段的一部分进行分享。