CAREER: Understanding and Harnessing the Fermentative Metabolism of Glycerol in E. coli: A New Path to Biofuels and Biochemicals

虽然生物柴油和生物乙醇等生物燃料代表了一种可持续、安全、可再生和对环境无害的化石燃料替代品，但要使它们在经济上可行，还需要重大的科学和技术突破。拟议研究的长期目标是阐明介导大肠杆菌中甘油厌氧发酵的途径和机制，并利用由此创建的知识库来设计这种有机体，以有效地生产还原性化学品和燃料。该研究计划的具体目标是：(1)研究培养基组成和培养条件对甘油发酵的影响；(2)利用遗传和生化方法评估假设途径在甘油发酵代谢中的作用；(3)利用功能基因组学工具鉴定参与甘油发酵的基因、蛋白质和代谢过程；(4)对大肠杆菌进行工程改造，使其能够高效地协同生产乙醇和氢气，从而说明使用甘油发酵作为生产生物燃料和生化产品的新平台的优势。为了实现这些目标，功能基因组学工具将用于补充传统的假设驱动方法。此外，代谢工程将作为一种合理的方法来改造大肠杆菌，使其将甘油转化为乙醇和氢。这一建议的智力价值与阐明大肠杆菌中甘油的发酵代谢有关，这是一个80多年来仍未解决的难题。通过推动和整合生物燃料的生产，该提案将有助于创造全新的过程和范例，例如那些拥抱生物炼制概念的过程和范例。这项研究也将为我们的社会教育做出重大贡献，使人们认识到生物燃料作为安全和可持续能源未来的推动者的作用。

Ramon Gonzalez0645188Although biofuels such as biodiesel and bioethanol represent a sustainable, secure, renewable, and environmentally safe alternative to fossil fuels, major scientific and technological breakthroughs are needed for them to become economically viable. The long-term goals of the proposed research are to elucidate the pathways and mechanisms mediating the anaerobic fermentation of glycerol in E. coli and use the knowledge base thus created to engineer this organism for the efficient production of reduced chemicals and fuels. The specific objectives of the research plan are: (1) study the effect of medium composition and cultivation conditions on glycerol fermentation, (2) assess the role of hypothesized pathways in the fermentative metabolism of glycerol by using genetic and biochemical approaches; (3) identify genes, proteins, and metabolic processes involved in the fermentation of glycerol using functional genomics tools; and (4) engineer E. coli for the efficient co-production of ethanol and hydrogen, thus illustrating the advantages of using glycerol fermentation as a new platform to produce biofuels and biochemicals. To achieve these goals, functional genomics tools will be used to supplement a traditional hypothesis-driven approach. In addition, metabolic engineering will be used as a rational approach to engineer E. coli for the conversion of glycerol into ethanol and hydrogen. The intellectual merit of this proposal relates to elucidating the fermentative metabolism of glycerol in E. coli, a puzzle that has remained unresolved for more than eighty years. By enabling and integrating the production of biofuels, this proposal will contribute to the creation of fundamentally new processes and paradigms such as those embracing the biorefinery concept. This research will also make significant contributions to the education of our society on the role of biofuels as enablers of a secure and sustainable energy future.