RIDGE: Tipping Points in the Evolution of Submarine Hydrothermal Systems: Habitat Generation, Organic Transformation, and Rock Alteration

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。极端环境下的微生物栖息地和脊顶热液系统的有机转化受到越来越多的关注，因为生活在这些环境中的微生物的新特性在生物勘探天然产物方面变得越来越重要，从而可以制造新药。这项研究本质上是理论性的，旨在通过计算“临界点”（即触发矿物反应和/或流体演化中最剧烈变化的温度、压力和成分条件）来指导这些微生物的发现。这项工作的重点是来自Ridge 2000综合研究地点的已知热液喷口系统，那里有广泛的热液喷口流体成分和矿物数据。该项目的目标是利用热力学约束和计算来预测居住在海底热液喷口的微生物群落的化学能供应。它还将侧重于向热力学数据库中添加数百种其他有机化合物的估计，以便对有机转化和有机化合物的非生物合成进行更完整和现实的计算。计算将检查存在于海中脊环境中的火成岩基底岩和沉积物的完整组成范围。通过专注于定位和理解引爆点，提出的工作与以往的大多数理论工作不同，并提供了一种新的方式来观察热液系统的演化，并确定高温或其他独特微生物生命形式的最佳采样位置。这项工作的广泛影响包括培训学生，为科学建设基础设施，为有机化合物提供急需的热力学数据，以及向公众宣传。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Microbial habitats in extreme environments and organic transformations at ridge-crest hydrothermal systems are receiving increased attention as the novel properties of microbes that live in these environments become increasingly important in terms of bioprospecting for natural products from which new drugs can be made. This research is theoretical in nature and designed to guide the discovery of such micro-organisms by calculating "tipping points" (i.e., temperature, pressure, and compositional conditions that trigger the most dramatic changes in mineral reactions and/or fluid evolution). The focus of the work is on known hydrothermal vent systems from the Ridge 2000 Integrated Study Sites where extensive hydrothermal vent fluid compositions and mineral data are present. Goals of the project are to use thermodynamic constraints and calculations to predict the supply of chemical energy to microbial communities that inhabit seafloor hydrothermal vents. It will also focus on adding estimates of hundreds of additional organic compounds to thermodynamic databases to allow more complete and realistic calculations of organic transformations and the abiotic synthesis of organic compounds. Calculations will examine the full compositional ranges of igneous basement rocks and sediments that exist in mid-ocean ridge settings. By focusing on locating and understanding tipping points, the proposed work departs from most previous theoretical work, and provides a new way of looking at the evolution of hydrothermal systems and identifying the best locations to sample for high temperature or other unique microbial life forms. Broader impacts of the work include student training, building infrastructure for science in terms of providing much needed thermodynamic data for organic compounds, and public outreach.