Collaborative Research: Investigating and Improving the Production of Butanol by C. Pasteurianum for the Value-Added Conversion of Biodiesel-Derived Crude Glycerol

0966846/0966818 Taconi/Bothun随着原油价格继续创历史新高，生物炼油成为可再生燃料和化学品生产的必要选择。然而，目前缺乏能够利用多种原料进行生物转化的强大和多功能的微生物。需要设计更好的工程微生物在综合生物精炼系统中发挥作用，以显著减少石油使用量，并开发各种基于生物质的工艺组合，以产生各种石油产品的可比替代品。利用生物柴油衍生的粗甘油生产丁醇是提高生物燃料行业总体可持续性的切实方法，特别是对生物柴油行业的增长和稳定至关重要。此外，利用粗甘油作为玉米原料的替代品，将为受玉米价格和可获得性限制的新兴生物精炼行业提供急需的多样性和灵活性。丁醇是一种重要的生物炼油平台化学品，作为一种可再生的交通燃料具有显著的优势。利用基本免费的原料产生更高产量的潜力加强了工业规模丁醇发酵的技术和经济可行性。智力价值本研究的目标是量化巴氏梭菌的新陈代谢和耐受性，并对该细菌进行改造，以提高生物柴油衍生的粗甘油的厌氧发酵增值转化。该项目将专注于基础研究，以了解和改善从细胞外和细胞内途径控制甘油利用和底物形成的代谢途径。拟议的研究有三个目标。第一个目标是阐明巴氏杆菌对底物和产物毒性的细胞反应。第二个目标是评估细胞膜的结构和稳定性，以响应底物杂质和丁醇浓度的增加。第三个目标是对巴氏杆菌进行代谢工程，以增加丁醇的产量。这项研究具有创新性，因为它提出了一种甘油发酵的替代途径，即利用代谢工程方法击倒还原途径中的基因，而不是上调氧化途径中的基因。这项研究具有潜在的变革性，因为它为微生物代谢工程开辟了新的途径，将生物精炼操作中的粗甘油副产品转化为液体运输燃料。广泛的影响该研究项目为学生和其他教育工作者提供了关于替代能源、可再生资源和生物精炼的教育机会。该教育计划将为研究生和本科生培养技术和实验室专业知识，为他们在目前正在经历大幅增长的生物燃料行业的职业生涯做好准备。计划开展各种外展活动，包括制定一项关于生物燃料生产和利用的研讨会和示范，教育幼儿至12岁的学生、教师和社区成员。教育工作还将侧重于通过以吸纳这些学生为目标的活动，从代表性不足的群体中招收学生。这些教育和外展活动将激发人们对科学和工程的广泛兴趣，并激励K-12学生接受高等教育并在工程和能源行业就业。拟议的外联活动还包括一个基于网络的维基网站和暑期交流计划，该计划将促进两个研究小组的研究生和本科生之间的合作。

0966846/0966818Taconi/BothunAs the price of crude oil continues to reach record highs, biorefining becomes a necessary option for renewable fuels and chemical production. However, robust and versatile microorganisms for bioconversion that can utilize multiple feedstocks are currently lacking. Better engineered microorganisms designed to function within an integrated biorefining system are required to significantly reduce petroleum utilization and develop a diverse portfolio of biomass-based processes that can generate comparable alternatives for a wide range of petroleum products.Utilization of biodiesel-derived crude glycerol for the production of butanol represents a tangible approach to improving the sustainability of the biofuels industry in general and is critical for the growth and stability of the biodiesel industry in particular. Furthermore, utilizing crude glycerol as an alternative to corn-derived feedstocks will provide much-needed diversity and flexibility to an emerging biorefining industry limited by the price and availability of corn. Butanol is a key biorefinery platform chemical and has significant advantages as a renewable transportation fuel. The potential to generate higher yields using an essentially no-cost feedstock strengthens the technical and economic feasibility for industrial-scale butanol fermentation.Intellectual MeritThe goal of this research is to quantify metabolism and tolerance in Clostridium pasteurianum and to engineer this bacterium to improve the value-added conversion of biodiesel-derived crude glycerol using anaerobic fermentation. This project will focus on fundamental research to understand and improve the metabolic pathways that control glycerol utilization and substrate formation from both extracellular and intracellular approaches. The proposed research has three objectives. The first objective is toelucidate the cellular response of C. pasteurianum to both substrate and product toxicity. The second objective is to evaluate cell membrane structure and stability in response to increasing concentrations of substrate impurities and butanol. And the third objective is to metabolically engineer C. pasteurianum to increase butanol production.The research is innovative because it proposes an alternative pathway to glycerol fermentation, where metabolic engineering approaches are used to knock down the genes in the reductive pathway as opposed to up-regulation of genes in the oxidative pathway. The research is potentially transformative because it opens up new approaches for metabolic engineering of microorganisms to convert crude glycerol byproducts from biorefinery operations to liquid transportation fuels.Broader ImpactsThis research project provides opportunities to educate students and other educators about alternative energy, renewable resources, and biorefining. The education plan will develop the technical and laboratory expertise for graduate and undergraduate students to prepare them for careers in the biofuels industry, which is currently experiencing substantial growth. Various outreach activities are planned, including the development of a seminars and demonstrations to educate K-12 students, teachers, and community members about biofuels production and utilization. Education efforts will also focus on the recruitment of students from underrepresented groups through activities that will target the inclusion of these students. These educational and outreach activities will stimulate broad interest in science and engineering, and inspire K-12 students to pursue higher education and careers in engineering and energy industries. The proposed outreach activities also include a web based wiki site and summer exchange program that will facilitate collaboration among graduate and undergraduate students in the two research groups.