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: 1251918
• 负责人: Clara Chan
• 金额: $ 22.6万
• 依托单位: University of Delaware
• 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=1251918&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.

微生物矿物质相互作用是地球表面地球化学循环的普遍存在和关键方面。在确定特定的微生物群体如何与矿物质相互作用（尤其是Fe氧化物）方面取得了重大进展。但是，尽管地质学家假设微生物参与产生经济S（0）沉积物，但几乎没有关于微生物制造和破坏元素硫的工作。在这一过程上的化学和生物控制尚不清楚，并且需要更好地理解影响S（0）生产和消耗的因素。深层地下的Frasassi洞穴系统中的硫酸含量已成为先前研究的目标。由于其独特的生物地球化学以及对人类探索的相对可访问性。洞穴生态系统是由微生物化学合成的维持，发生在其泛硫和微氧含水层的表面附近。洞穴水中明显的白色生物膜包含质量为20％至80％的元素硫。因此，其地球化学和微生物学特征使弗拉萨西成为研究与S（0）微生物相互作用的有前途的系统，S（0）是硫循环中重要的固相中间体。来自全球分布的和很大程度上未经文化的硫属枝的神秘性Epsilonproteobacteria是Frassasi Biofilms的主要参与者。它们在硫化物高和低氧供应水中特别丰富，由于电子受体的可用性有限，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，研究人员正在将元文字组学，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）蓄意生物膜社区的新了解。这项研究将提高对（i）微生物在产生地质S（0）沉积物中的作用； （ii）与固相S（0）微生物相互作用的机制； （iii）目前未培养的epsilonproteobacteria的代谢能力。该研究支持将现代和古代生物地球化学整合遗传和地球化学理解的长期目标。项目资金提供了指导两名研究生和一名博士后学者的指导。拟议的项目为洞穴和极端微生物的兴趣提供了向公众推广的出色机会。该项目的图像和微生物培养物将在两个非常成功的年度事件中使用：PSU探索日和PSU地球科学系。去年，这些活动吸引了2000多个K-12学生和父母，150名三年级学生。 Microslide Procems Cultures将被纳入动手6-12年级的教师研讨会和地球学院，海洋与环境学院在Lewes Campus的年度沿海日，这是一种34年的传统，现在吸引了数千名社区成员。结果也将作为海洋新闻通讯的De Sea Grant的一部分，以及NPR上的Sea Talk Radio片段。