International Research Fellowship Program: Biomass-Derived Fuels: Modeling and Simulation of Enzymatic Processes

[07:00080]国际研究奖学金计划使美国科学家和工程师能够到国外进行9至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Jim Pfaendtner博士与Michele Parrinello博士在瑞士苏黎世联邦理工学院进行为期24个月的研究。毫无疑问，确保充足的清洁可再生能源供应是本世纪科学家面临的最大挑战之一。化石燃料的惊人消耗加剧了气候变化和地缘政治不稳定，而且是高度不可持续的。实际上，鉴于供应有限以及西方和发展中国家石油消费的高速增长，没有办法解决即将到来的“能源危机”。据估计，目前我们的能源组合中只有8%来自可再生能源，但为了满足社会的能源需求，这一贡献必须在未来大幅增长。可再生能源组合增长的一个主要领域将来自生物质衍生燃料。目前阻碍生物质在燃料生产中广泛使用的两个主要障碍是：1)非生产性木质素-酶结合减缓了催化作用；2)缺乏有效的酶来消化植物细胞内的坚固物质。实验技术本身不能充分解决这些问题，因为难以测量基本反应的速率和酶在其动力学的时间尺度上的运动。提出的工作的目的是开发一个新的建模框架，利用粗粒度分子模拟和新的自由能采样方法来探测这些现象。PI和主机正在建立新的多尺度模型，将原子水平的信息传播到与生物燃料生产相关的时间/长度尺度。这个新的建模框架被用于研究木质素/纤维素酶系统的结构-性质关系，以及研究内切-1,4-木聚糖酶对木聚糖的酶切作用。这项工作对社会的明显影响将是提高人们对如何从生物质中获得可持续燃料的理解。社会在生活的各个方面都对能源和燃料有着巨大的依赖。除了燃烧化石燃料，我们目前还没有发达的技术来满足我们的能源需求。因此，开发可持续燃料对于维持我们的生活方式至关重要。

0700080PfaendtnerThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Jim Pfaendtner to work with Dr. Michele Parrinello at ETH in Zurich, Switzerland.Securing an abundant supply of clean, renewable energy is without question one of the greatest challenges facing scientists in this century. The alarming consumption of fossil fuels contributes to climate change and geopolitical instability and, moreover, is highly unsustainable. In practical terms, there is no solution to the coming ``energy crunch'', given limited supplies and the high growth rate in oil consumption in the west and the developing world. Our energy portfolio now contains, by some estimates, as little as 8% from renewables, but this contribution must grow dramatically in the future in order to address the energy needs of society. One main area of growth in the renewable energy portfolio will be from biomass-derived fuels. Two main obstacles currently preventing the broad use of biomass in the production of fuels are 1) non-productive lignin-enzyme binding that slows catalysis and 2) the lack of efficient enzymes that can digest robust materials within plant cells. Experimental techniques alone cannot sufficiently address these problems due to difficulties in measuring the rates of elementary reactions and enzyme motions on the time scale of their dynamics. The object of the proposed work is to develop a new modeling framework to probe these phenomena using coarse-grained molecular simulation and new free-energy sampling methods. The PI and host are building new multiscale models that propagate atomic-level information to time/length scales relevant to the production of biofuels. This new modeling framework is being used to study structure-property relationships in the lignin/cellulase system as well as to investigate the enzymatic digestion of xylan by endo-beta-1,4-xylanase. The clear impact of this work on society will be an improved understanding of how to obtain sustainable fuels from biomass. Society has an enormous dependence on energy and fuels in all aspects of life. Other than burning fossil fuels, we currently have no developed technologies that can meet our energy needs. As such, developing sustainable fuels is critically important in sustaining our way of life.