SusChEM: Novel 1,2-Propanediol Biosynthesis from Renewable Feedstocks through Enzyme Discovery

SusChEM：通过酶发现从可再生原料生物合成新型 1,2-丙二醇

• 批准号: 1438332
• 负责人: Wei Niu
• 金额: $ 31.76万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1438332&HistoricalAwards=false
• 关键词: SusChEM; Novel; Propanediol; Biosynthesis; Renewable

SusChEM: Novel 1,2-Propanediol Biosynthesis from Renewable Feedstocks Through Enzyme DiscoveryAfter many years of practice, the chemical industry faces sustainability challenges that arise from both the potentially dwindling feedstocks and intermediates that are derived from fossil fuels, and from the increasingly undesirable environmental costs associated with their production. Biocatalytic syntheses, based on enzymatic conversion or microbial whole-cell synthesis, are increasingly explored as the alternate platform of chemical production. Key advantages of microbial synthesis over chemical syntheses include reaction selectivity, molecular diversity, and reduced environmental impact, and the utilization of renewable feedstocks, such as plant-based cellulosic material, instead of hydrocarbons. The successful implementation of microbial syntheses inherently addresses the sustainability challenges currently facing the chemical industry. Because natural pathways are often not suitable for large-scale chemical production, and do not lead to desired chemical products, efforts are needed into the discovery and the development of novel biosynthetic pathways for industrial chemicals. Professors Wei Niu and Jiantao Guo at the University of Nebraska-Lincoln propose to achieve sustainable production of an industrial bulk chemical, 1,2-propanediol (1,2-PDO), by developing a new biosynthetic route. 1,2 PDO may be integrated into the production of other chemicals, such as n-propanol and propylene. This study combines both the discovery and the engineering aspects of scientific research. UN-L Students participating in this work will gain perspectives on the important aspects and synergistic effects of integrating basic science and engineering. The multidisciplinary research activities will be used to support active recruitment of underrepresented undergraduate and graduate students to pursue studies and careers in STEM areas.The scientific goal of the proposed work is to establish the de novo biosynthesis of 1,2-propanediol, an industrial bulk chemical and a natural product, from renewable feedstocks through the reduction of a common fermentation product, lactic acid. Application of the two known 1,2-PDO biosynthetic routes is limited either by the scarce availability of the starting material or the involvement of cytotoxic biosynthetic intermediate. The PIs seek to overcome these limitations by establishing novel 1,2-PDO pathways using two parallel approaches. The first one is a discovery-driven approach that focuses on identifying the genetic and catalytic elements that function in the poorly understood lactic acid reduction pathway in Lactobacillus buchneri, which produces 1,2-PDO under anoxic growth conditions. The second one is a design and engineering-driven approach that focuses on the development of a novel artificial 1,2-PDO biosynthetic pathway, which entails the activation of lactic acid as lactoyl-CoA followed by two sequential reduction steps to form 1,2-PDO. This pathway would also enable the stereospecific biosynthesis of R- and S-1,2-PDO stereoisomers. Niu and Guo will apply protein engineering to improve the catalytic efficiency of the bottleneck enzyme, the CoA-dependent aldehyde dehydrogenase. To facilitate rational mutagenesis, efforts will be directed to obtain the crystal structure of the protein, of which the family is underrepresented in available protein structure database. In addition, the proposed work will establish a novel growth-coupled selection scheme to allow rapid sampling of large number of enzyme mutants. The selection scheme has the potential to be adapted for directed evolution of other enzymes that have similar cofactor requirement.

Suschem：新颖的1,2-丙二醇生物合成从可再生原料中通过酶的酶发现了多年的实践，化学工业面临可持续性挑战，这些挑战均来自潜在的衰落的原料和中间体，这些挑战与化石燃料以及越来越多的不良环境成本相关。 基于酶促转化或微生物全细胞合成的生物催化合成越来越多地作为化学生产的替代平台探索。微生物合成比化学合成的关键优势包括反应选择性，分子多样性和降低的环境影响以及可再生原料的利用，例如植物性纤维素材料，而不是碳氢化合物。微生物合成的成功实施固有地解决了当前面临化学工业面临的可持续性挑战。由于自然途径通常不适合大规模化学生产，并且不会导致所需的化学产品，因此需要在发现和开发新型工业化学品的生物合成途径中努力。 内布拉斯加州林肯大学的Wei Niu和Jiantao Guo教授建议通过开发新的生物合成途径来实现1,2-丙二醇（1,2-PDO）的工业体积化学物质的可持续生产。 1,2 PDO可以集成到其他化学物质的生产中，例如N-丙醇和丙烯。 这项研究结合了科学研究的发现和工程方面。 参加这项工作的非L-L学生将对整合基础科学和工程的重要方面和协同效应获得观点。 The multidisciplinary research activities will be used to support active recruitment of underrepresented undergraduate and graduate students to pursue studies and careers in STEM areas.The scientific goal of the proposed work is to establish the de novo biosynthesis of 1,2-propanediol, an industrial bulk chemical and a natural product, from renewable feedstocks through the reduction of a common fermentation product, lactic acid. 使用两种已知的1,2-PDO生物合成路线的应用受到起始材料的稀缺性或细胞毒性生物合成中间体的参与而受到限制。 PI寻求通过使用两种平行方法来建立新颖的1,2-PDO途径来克服这些局限性。 第一个是一种发现驱动的方法，该方法侧重于识别在乳酸乳杆菌乳酸杆菌还原良好的乳酸还原途径中起作用的遗传和催化元素，在缺氧生长条件下会产生1,2-PDO。 第二种是设计和工程驱动的方法，该方法着重于开发新型的人造1,2-PDO生物合成途径，该途径需要将乳酸作为乳酸-COA的激活，然后采取两个顺序还原步骤以形成1,2-PDO。该途径还将使R-和S-1,2-PDO立体异构体的立体特异性生物合成。 NIU和GUO将采用蛋白质工程来提高瓶颈酶的催化效率，COA依赖性醛脱氢酶。 为了促进合理诱变，将努力努力获得蛋白质的晶体结构，在该蛋白质中，该家族在可用的蛋白质结构数据库中的代表性不足。 此外，提出的工作将建立一种新型的生长耦合选择方案，以允许大量酶突变体的快速采样。 选择方案有可能适应具有相似辅助因素的其他酶的定向演化。