RII Track-4: Elucidating Enzyme-Ionic Liquid Interactions to Enable Effective Lignin Valorization

RII Track-4：阐明酶-离子液体相互作用以实现有效的木质素增值

• 批准号: 1929122
• 负责人: Jian Shi
• 金额: $ 20.13万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929122&HistoricalAwards=false
• 关键词: RII; Track; Elucidating; Enzyme; Ionic

Shifting society's dependence on petroleum-based fuels and chemicals to biomass derived products is important not only to reduce our carbon usage but also to increase the robustness of our energy security and economic stability. To that end, the environmentally benign reuse or upgrading of materials considered byproducts of industrial and agricultural economies is one of the ultimate goals of sustainable practices. Lignin, as the most abundant aromatic polymers in nature, provides structural strength and protection against microbial/enzymatic degradation of plants. It is available in quantity of over 100 million dry tons as a waste stream from paper and pulping industry. Despite its great potential as a feedstock for making a wide range of chemicals, lignin is still an underutilized substrate. Under the current bio-refinery concept, lignin is commonly burned to generate steam and electricity. Converting lignin waste streams to high value-added chemicals and materials is critical for the economic viability and success of a bio-refinery industry. The successful demonstration of the proposed work will provide a novel biocatalysis route for valorizing lignin from relevant waste streams to high value commodity and specialty chemicals, greatly reducing barriers along the biofuels supply chain. This project will also integrate outreach and education activities for underprivileged groups from the Appalachian region in STEM fields.Two key challenges hindering effective lignin conversion are to improve the contact of the bulky poorly soluble lignin polymer to the catalyst and the selective/controlled breakdown of inter-unit linkages. Elucidating the interactions of lignolytic enzyme with ionic liquid (IL) will allow a more rational approach to synthesize better ILs and the ability to reengineer better enzymes to optimize their activities in aqueous IL solution. This EPSCoR Research Fellowship provides a unique opportunity for the PI to visit and collaborate with the Environmental Molecular Sciences Laboratory (EMSL) at the Department of Energy (DOE)'s Pacific Northwest National Laboratory. The overarching goal is to explore IL-enzyme interfaces through extended visits to EMSL by accessing the nation's premier scientific user facilities and build on efforts to develop innovative biocatalysis pathways to convert lignin to high value chemicals. The research will involve: 1) mechanistic understanding of lignin solubility, selective lignin depolymerization and enzyme compatibility with aqueous ILs; 2) exploration of new IL-lignolytic enzyme pairs via advanced EPR/NMR, bioimaging, spectrophotometry and computational chemistry capacities at EMSL to probe interfacial interactions between IL-enzyme-lignin. A better understanding of such interactions will guide our future research to design new biocompatible ILs, engineer better enzymes via directed evolution/modifying surface charges, or explore new membrane/catalyst interfaces, to further improve product yield and selectivity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

将社会对石油基燃料和化学品的依赖转变为生物质衍生产品不仅对减少我们的碳使用量很重要，而且对提高我们的能源安全和经济稳定性也很重要。为此，对被视为工业和农业经济副产品的材料进行无害环境的再利用或升级是可持续做法的最终目标之一。木质素作为自然界中最丰富的芳香族聚合物，为植物提供结构强度和防止微生物/酶降解的保护。作为造纸和制浆工业的废物流，它的数量超过1亿干吨。尽管木质素作为制造各种化学品的原料具有巨大潜力，但它仍然是一种未充分利用的底物。在目前的生物炼油概念下，木质素通常被燃烧以产生蒸汽和电力。将木质素废物流转化为高附加值的化学品和材料对于生物炼油工业的经济可行性和成功至关重要。拟议工作的成功演示将提供一种新的生物催化途径，用于将木质素从相关废物流中增值为高价值商品和特种化学品，大大减少生物燃料供应链的沿着障碍。 该项目还将为阿巴拉契亚地区的贫困群体在STEM领域开展推广和教育活动。阻碍木质素有效转化的两个关键挑战是改善大体积难溶性木质素聚合物与催化剂的接触以及单元间键的选择性/受控分解。阐明木质素降解酶与离子液体（IL）的相互作用将允许一个更合理的方法来合成更好的IL和改造更好的酶的能力，以优化其在IL水溶液中的活性。该EPSCoR研究奖学金为PI提供了一个独特的机会，可以访问能源部（DOE）太平洋西北国家实验室的环境分子科学实验室（EMSL）并与之合作。总体目标是通过访问国家首屈一指的科学用户设施，并通过扩展对EMSL的访问，探索IL-酶界面，并努力开发创新的生物催化途径，将木质素转化为高价值的化学品。研究将涉及：1）对木质素溶解性、选择性木质素解聚和酶与含水IL的相容性的机理理解; 2）通过先进的EPR/NMR、生物成像、分光光度法和EMSL的计算化学能力探索新的IL-木质素分解酶对，以探测IL-酶-木质素之间的界面相互作用。对这种相互作用的更好理解将指导我们未来的研究，设计新的生物相容性离子液体，通过定向进化/修饰表面电荷设计更好的酶，或探索新的膜/催化剂界面，以进一步提高产品收率和选择性。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。