CAREER:Geochemical Energy for Thermophilic Archaea and Bacteria

职业：嗜热古细菌和细菌的地球化学能源

• 批准号: 0447231
• 负责人: Jan Amend
• 金额: $ 53.9万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-15 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0447231&HistoricalAwards=false
• 关键词: CAREER; Geochemical; Energy; Thermophilic; Archaea

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.

越来越多的证据表明，微生物非凡的新陈代谢和系统发育多样性是数十亿年来与地质过程共同进化的结果。在可预见的未来，研究地球化学和微生物学之间的密切联系将成为地质学研究的一个更大的重点。研究生物-地球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，在地球化学和微生物方面高度多样化，即使是复杂的调查也很容易进入，与深海和大陆对应的生态系统相比，研究不足。我的主要职业兴趣是了解地球化学对新陈代谢多样性的制约，并研究微生物在控制其化学环境中所起的作用。这两个过程之间的关键环节是什么？微生物学和地球化学之间的关系呢？化学能源的可获得性。量化嗜热古生菌和细菌的地球化学能是我未来研究的核心。我已经制定了一项研究和教育活动的综合计划，将为长期的学术生涯奠定基础。该计划包括通过创新的课程设置和对研究生和本科生的实践指导，扩大华盛顿大学的地球生物学和地球化学。新课程试图解决课程中已发现的几个弱点，包括地球生物学的实地/实验室课程、自然科学的写作强化课程，以及涵盖特殊和及时感兴趣的主题的多学科研讨会。这里提出的教育部分还试图(通过科学俱乐部)为低收入的城市地区小学提供几个额外的学习机会；最终的挑战是消除学生群体之间存在的“成绩差距”。这项活动将与各种K-5学校和许多地方科学和自然中心的公共推广计划、教师和志愿者进行协调。我在微生物地球化学方面的新研究方向包括：1)设计地化现实的生长介质，在热液生态系统中培养迄今无法培养的嗜热菌；2)在喷口环境中原位测定一系列氧化还原过程的能量产率，包括有机化合物的氧化和发酵以及含砷化合物的转化；3)进入细胞内部，量化常见和中心生化途径的自由能作为温度和压力的函数，包括分解代谢(能量产生)和合成代谢(生物合成)反应网络。这些方法结合了实地工作(现场测量、采样)、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)。总体目标是生成热液系统中生物地球化学界面的定量、预测和综合模型，并开发必要的科学工具来测试、指导和提高我们对全球生物地球化学过程的理解。