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纤维素水解酶的开发提供目标，这些酶将应用于生物质转化为糖。研究结果将对Iogen公司（加拿大公司和世界领先的生物质转化）努力开发高效，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改进的主要目标，因为酶制造成本高，纤维素不易水解。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，但实际发生的化学和结构变化却鲜为人知。因此，底物和纤维素酶之间的相互作用也是一个黑盒子。生产性和非生产性相互作用的鉴定和表征将为底物和酶的改进提供目标。大学的研究团队将采用光谱、表面成像和表面分析技术来更好地理解：1)水解的速率决定步骤是什么？2)酶识别水解的生产位点的特征是什么？3)我们如何使酶的表面隔离有利于与生产位点的结合？4)酶是否会卡住并阻塞生产位点？5)酶如何为其他酶创造位点？我们的目标是为这些基本问题提供答案，为酶和工艺的发展提供方向。越来越多的证据表明，生物基产品在能源、化学品和材料方面可以成为目前以化石为基础的原料的经济上有竞争力的替代品。这对加拿大尤其重要，因为加拿大每年生产大量的森林和农业生物量。以生物为基础的经济将对农业和林业产生长期影响。此外，用生物质代替石油开发燃料、化学品和材料将减少二氧化碳排放和其他温室气体（如一氧化二氮）的排放。

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.