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

智力价值：这项研究探索地球化学过程如何支持生活在地球深处的微生物。了解生命如何在深海生存的一个主要挑战是微生物消耗的有机化合物的身份和来源。虽然其中一些化合物可能是由其他地下微生物产生的，但这项工作的重点是可消耗有机化合物的大量库存，这些化合物来自于沉积物被掩埋并暴露在高温高压下时有机质的地球化学转化。这项工作的目标是从理论上和实验上研究在微生物生命无法承受的温度和压力下发生的化学反应。这些高温高压反应产生有机溶质，这些溶质向上输送到地下有人居住的区域。这项研究的主要重点是确定热水和有机物之间的反应如何产生最终为深层生物圈提供食物的小有机化合物。第一阶段的重点是众所周知的水热反应实验，在高温高压下将简单的碳氢化合物转化为醇、酮和羧酸。第二阶段探索这些相同的反应，但在一个更现实的背景下，因此复杂的地质系统，包括在所有有机丰富的沉积物和沉积岩中发现的粘土矿物。这些反应大都没有在地质现实条件下进行系统的研究。因此，我们目前对自然界这些转化机制的理解是推测性的。这项工作产生了严格的结果，可以通过计算来预测地球深处地区的微生物代谢潜力。地壳。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，并为地球化学家提供了有机物质转化的新预测机制模型。新的模型将为未来探索深层生物圈的海洋和大陆钻探工作的选址提供信息，并将使我们更好地了解石油的产生。该项目还提供了一种预测在哪里可以找到具有不寻常性质的新微生物物种的方法。水热反应器方法也可以为焚烧或掩埋有机废物提供绿色替代品。在教育和培训方面，这项工作支持博士后、研究生和本科生，并支持在科学领域性别代表性不足的pi。公众外展将包括为？I？我想上大学？程序。与该项目相关的研究生和本科生研究人员将帮助开发新的地球/地球科学演示并协调学生志愿者。示范、作业和课程计划将在“我是大学之旅”网站上发布。

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.