ETBC: Organic Geochemical Transformations and the Deep Biosphere -- Identifying the Food Sources for Microbes in Sedimentary Systems

ETBC：有机地球化学转化和深层生物圈——识别沉积系统中微生物的食物来源

• 批准号: 0826588
• 负责人: Everett Shock
• 金额: $ 147.86万
• 依托单位: Arizona State University
• 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 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0826588&HistoricalAwards=false
• 关键词: ETBC; Organic; Geochemical; Transformations; Deep

Intellectual Merit: This research explores how geochemical processes support microbes living deep in the Earth. A major challenge in understanding how life can survive at depth is the identity and source of organic compounds that are consumed by microbes. While some of these compounds are likely to be produced by other subsurface microbes, this works focuses on the large inventory of consumable organic compounds that comes from geochemical transformations of organic matter that take place as sediments are buried and exposed to elevated temperatures and pressures. Goals of the work are to examine, both theoretically and experimentally, chemical reactions that occur at temperatures and pressures greater than microbial life can withstand. These high temperature and pressure reactions produce organic solutes that are transported upward into the inhabited zones of the subsurface. The primary focus of the research is to determine how reactions between hot water and organic matter generate small organic compounds that ultimately feed the deep biosphere. Phase I focuses on hydrothermal experiments of well-known reactions that transform simple hydrocarbons into alcohols, ketones, and carboxylic acids at elevated temperatures and pressures. Phase II explores these same reactions, but in the context of a more realistic and thus complex geologic system that includes the clay minerals found in all organic rich sediments and sedimentary rocks. Most of these reactions have not been systematically studied under geologically realistic conditions. As a result, our present understanding of these transformation mechanisms in nature are speculative. This work produces rigorous results from which calculations can be made to predict the microbial metabolic potential of areas deep within the Earth?s crust. Broader Impacts: This work provides organic chemists with new methods to control reactions and provides geochemists with new predictive, mechanistic models of organic matter transformations. New models will inform those making site selections for future ocean and continental drilling efforts that explore the deep biosphere and will allow us to better understand the generation of petroleum. This project also provides a means to predict where prospecting of new microbial species with unusual properties can be found. The hydrothermal reactor approach may also provide green alternatives to incineration or burial of organic waste. In terms of education and training, the work supports post-docs, graduate students, and undergraduates, and supports PIs whose gender is under-represented in the sciences. Public outreach will include development new materials for the ?I?m College Bound? program. Graduate and undergraduate researchers associated with this project will help develop new geo/earth science demonstrations and coordinate student volunteers. The demonstrations, assignments and lesson plans will be disseminated and published on the "I'm College Bound" web site.

智力优点：这项研究探讨了地球化学过程如何支持生活在地球深处的微生物。了解生活如何在深度生存的主要挑战是微生物消耗的有机化合物的身份和来源。尽管其中一些化合物可能是其他地下微生物产生的，但这项工作集中于大量的可消耗有机化合物库存，这些化合物来自有机物的地球化学转换，这些变化是有机物的地球化学转化，由于沉积物被埋葬并暴露于高温和压力上。 这项工作的目标是在理论上和实验上检查，在温度和压力下发生的化学反应比微生物寿命可以承受。 这些高温和压力反应会产生有机溶质，这些溶质被向上运输到地下的居住区域。这项研究的主要重点是确定热水与有机物之间的反应如何产生最终喂养深层生物圈的小有机化合物。第一阶段的重点是在高温和压力下将简单的碳氢化合物转化为醇，酮和羧酸的热液实验。第二阶段探讨了这些相同的反应，但在一个更现实，更复杂的地质系统的背景下，其中包括在所有有机富含有机的沉积物和沉积岩石中发现的粘土矿物。 这些反应中的大多数尚未在地质现实条件下系统地研究。 结果，我们对自然界这些转变机制的当前理解是投机性的。 这项工作产生了严格的结果，可以从中进行计算以预测地壳深处地区的微生物代谢潜力。更广泛的影响：这项工作为有机化学家提供了控制反应的新方法，并为地球化学主义者提供了有机物转化的新预测机械模型。新模型将告知那些为未来的海洋和大陆钻探工作进行现场选择，以探索深层生物圈，并使我们能够更好地了解石油的产生。该项目还提供了一种预测具有异常特性的新微生物物种的方法。 水热反应器方法还可以为焚烧或埋葬有机废物提供绿色替代方案。 在教育和培训方面，这些工作支持博士后，研究生和本科生，并支持科学中性别不足的PI。 公共宣传将包括开发？程序。与该项目相关的研究生和本科研究人员将有助于开发新的地理/地球科学演示并协调学生志愿者。演示，作业和课程计划将在“我的大学绑定”网站上传播和发布。