CAREER:Geochemical Energy for Thermophilic Archaea and Bacteria

摘要越来越多的证据表明，微生物非凡的代谢和系统发育多样性是几十亿年来与地质过程共同进化的结果。在可预见的将来，研究地球化学和微生物学的密切耦合将成为地质研究的一个更大的焦点。调查生物-地质界面的最佳和最令人兴奋的地点之一是浅海热液生态系统;它们无处不在，地球化学和微生物高度多样化，甚至可以进行复杂的调查，与深海和大陆对应物相比，研究不足。我的主要职业兴趣是了解代谢多样性的地球化学约束，并调查微生物在控制其化学环境中的作用。这两个过程之间的重要联系？以及微生物学和地球化学之间的联系是化学能源的可用性。对嗜热古菌和细菌的地球化学能量进行量化是我未来研究的核心。我已经制定了一个研究和教育活动的综合计划，这将为长期的学术生涯奠定基础。该计划包括通过创新课程和对研究生和本科生的实践指导来扩大华盛顿大学的地球生物学和地球化学。新的课程，力求解决几个确定的弱点，在课程，包括在地球生物学领域/实验室类，在自然科学写作密集课程，以及多学科研讨会，涵盖特殊和及时的利益的主题。这里提出的教育部分还试图在低收入的城市地区小学提供一些额外的学习机会（通过科学俱乐部）;最终的挑战是消除学生群体之间存在的“成绩差距”。我在微生物地球化学方面的新研究方向包括：1）设计地球化学上现实的生长介质，在热液生态系统中培养迄今为止“不可培养”的嗜热菌; 2）确定喷口环境中一系列氧化还原过程的现场能量产出，包括有机化合物的氧化和发酵以及含砷化合物的转化;以及3）“进入细胞内部”以量化作为温度和压力的函数的常见和中心生化途径的自由能，包括分解代谢（能量产生）和合成代谢（生物合成）反应网络。这些方法结合了联合收割机现场工作（原位测量、取样）、分析化学（水溶液、气体、矿物）、实验微生物学（嗜热菌培养、基因调查）和定量建模（反应能量学、热力学性质估计）。其总体目标是生成热液系统中地球化学界面的定量，预测和综合模型，并开发测试，指导和提高我们对全球地球化学过程的理解所需的科学工具。

ABSTRACTEvidence is mounting that the extraordinary metabolic and phylogenetic diversity of microorganisms is the result of several billion years of co-evolution with geologic processes. Investigating the intimate couplings of geochemistry and microbiology will become an even greater focus of geologic research in the foreseeable future. Among the best and most exciting sites to investigate the bio-geo interface are shallow marine hydrothermal ecosystems; they are ubiquitous, geochemically and microbiologically highly diverse, readily accessible for even complex investigations, and understudied compared to their deep-sea and continental counterparts. My primary career interests are understanding the geochemical constraints on metabolic diversity and investigating the role that microorganisms play in controlling their chemical environment. A crucial link between these two processes ? and between microbiology and geochemistry in general? is the availability of chemical energy sources. Quantifying the geochemical energy for thermophilic archaea and bacteria is at the core of my future studies.I have developed an integrated plan for research and education activities that will build a foundation for a long-term academic career. The plan includes expanding geobiology and geochemistry at Washington University through innovative course offerings and hands-on mentoring of graduate and undergraduate students. New courses, which seek to address several identified weaknesses in the curriculum, include a field/lab class in geobiology, a writing intensive course in the natural sciences, and multidisciplinary seminars that cover topics of exceptional and timely interests. The educational component proposed here also seeks to provide several extra learning opportunities (through Science Clubs) in low-income, urban area elementary schools; the ultimate challenge is to eliminate the "achievement gap" that exists between groups of students. This activity will be coordinated with established public outreach programs, teachers and volunteers at various K-5 schools, and numerous local science and nature centers.My new research directions in microbial geochemistry include 1) designing geochemically realistic growth media to culture heretofore "unculturable" thermophiles in hydrothermal ecosystems; 2) determining in situ energy-yields for an array of redox processes in vent environments, including the oxidation and fermentation of organic compounds and the conversion of Arsenic-bearing compounds; and 3) going "inside the cell" to quantify the free energies of common and central biochemical pathways as a function of temperature and pressure, both catabolic (energy-producing) and anabolic (biosynthesis) reaction networks. The approaches combine fieldwork (in situ measurements, sampling), analytical chemistry (aqueous solutions, gases, minerals), experimental microbiology (thermophile culturing, gene surveys), and quantitative modeling (reaction energetics, estimation of thermodynamic properties). The overall objectives are to generate quantitative, predictive, and comprehensive models of the biogeo interface in hydrothermal systems and to develop the scientific tools needed to test, guide, and improve our understanding of global biogeochemical processes.