Engineering cellulosic ethanol: Surface analysis of cellulose biodegradation

该项目的目标是确定底物结构和化学的关键参数，这些参数将为生物质预处理和应用于生物质转化为糖的纤维素酶的开发提供目标。研究结果将对Iogen公司(加拿大公司，生物质转化的世界领先者)努力开发高效率、低成本的纤维素乙醇工艺具有重要价值。从纤维素到葡萄糖的酶转化步骤是一个主要的改进目标，因为酶的制造成本很高，而且纤维素对水解的抵抗。虽然木质纤维素的化学和物理预处理是使底物更容易受到酶攻击的传统方法，但人们对实际发生的化学和结构变化知之甚少。因此，底物和纤维素酶之间的相互作用也是一个黑匣子。产生性和非产生性相互作用的鉴定和表征将为底物和酶的改进提供目标。该大学的研究团队将使用光谱、表面成像和表面分析技术来更好地理解：1)决定水解速度的步骤是什么？2)酶识别的产生部位的特征是什么？3)我们如何使酶的表面隔离偏向于与产生部位的结合？4)酶会被粘住并阻碍产生部位吗？5)酶如何为其他酶创造产生部位？我们的目标是为这些基本问题提供答案，为酶和过程的发展提供方向。越来越多的证据表明，生物产品可以成为目前以化石为基础的能源、化学品和材料原料的具有经济竞争力的替代品。这与加拿大特别相关，加拿大的森林和农业生物质年产量巨大。生物经济将对农业和林业社区产生长期影响。此外，从生物质而不是石油中开发燃料、化学品和材料将减少二氧化碳排放和一氧化二氮等其他温室气体。

The objective of this project is to identify critical parameters of substrate structure and chemistry that will provide targets for development of biomass pretreatment and cellulolytic enzymes to be applied to the conversion of biomass to sugars. The results of the research will be of significant value to Iogen Corporation (Canadian company and a world leader in biomass conversion) in their efforts to develop a high efficiency, low cost cellulose ethanol process. The enzymatic conversion step from cellulose to glucose is a principal target for improvement due to the high cost of enzyme manufacture and the recalcitrance of cellulose to hydrolysis. Although chemical and physical pretreatments of lignocellulose are traditional methods for making substrate more susceptible to enzymatic attack, the actual chemical and structural changes occurring are poorly understood. Consequently, the interactions between the substrate and the cellulase enzymes is also a black box. The identification and characterization of both productive and non-productive interactions will provide targets for improvements to both substrate and enzyme. The University research team will employ spectroscopic, surface imaging and surface analytical techniques to better understand:1) What are the rate determining steps of hydrolysis? 2)What are the characteristics of a productive site that an enzyme recognizes for hydrolysis? 3)How can we bias surface sequestration of enzymes to favor binding to productive sites? 4)Do enzymes get stuck and block productive sites? 5) How do enzymes create sites for other enzymes? Our goal is to provide answers to these fundamental questions that provide direction for enzyme and process development. Growing evidence suggests that the bio-based products can be economically competitive alternatives to current, fossil-based feedstocks for energy, chemicals and materials. This is particularly relevant for Canada which has a huge annual production of forest and agricultural biomass. The bio-based economy will have a long term impact on the farming and forestry community. In addition,the development of fuels, chemicals and materials from biomass instead of petroleum will reduce carbon dioxide emission and other GHGs such as nitrous oxide.