Development of an engineered cellulosome-based cellulase/hemicellulase system for efficient, cost-effective hydrolysis of cellulose from agricultural and woody feedstocks

格林兄弟（Rumpelstilskin）的一个童话讲述了把稻草变成金子的故事。在该方案中，将在纳米和生物技术领域开发新技术，将农业（玉米秸秆、小麦秸秆）和木质（木屑和锯末）原料转化为绿色黄金（乙醇形式的生物燃料）。绿色黄金技术与传统的黑金（石油）技术在两个方面有显著不同。1.从地下开采原油和使用汽油作为运输燃料的过程释放了大量的温室气体。这些温室气体与全球变暖有关，在不久的将来会对人类产生重大影响。使用乙醇作为运输燃料可以最大限度地减少温室气体排放。2.与总有一天会耗尽的原油相比，生物乙醇可以从可再生资源中产生。目前，生物乙醇生产涉及三种技术。这些包括巴西从甘蔗中提取的糖乙醇，北美从玉米和小麦中提取的谷物乙醇，以及许多国家从玉米秸秆和小麦秸秆中提取的纤维素乙醇。由于加拿大不是理想的甘蔗种植和谷物乙醇的方法已经引起了主要关注的看法粮食燃料，纤维素乙醇是加拿大的最佳选择。然而，将纤维素分解成葡萄糖所需的酶（纤维素酶和半纤维素酶）相对复杂且昂贵。因此，需要新的技术来提高这些酶的活性并降低生产成本。在这个提议中，一个微小的蛋白质平台将被设计成捕获不同的酶，形成一个纳米酶复合物，它可以协同工作来分解纤维素。这些酶将以预定的顺序在平台上组装。降解中间体将从一种酶扩散到紧邻的另一种酶。选择高效酶并入平台。所有这些成分都将使用我实验室开发的微生物工厂（枯草芽孢杆菌，一种非致病性细菌）重组生产。这些技术，如果开发成功，将使纤维素乙醇生产真正具有成本效益。

A fairy tale from the Grimm brothers (Rumpelstilskin) talks about turning straws into gold. In this proposal,new technologies will be developed in areas of nano- and bio-technologies to turn agricultural (corn stovers,wheat straws) and woody (wood chips and sawdust) feedstocks to green gold (biofuels in the form of ethanol).The green gold technology is significantly different from the traditional black gold (petroleum) technology intwo aspects. 1. The process of extracting crude oil from the ground and using gasoline as the transport fuelrelease significant amounts of greenhouse gases (GHG). These GHGs have been linked to global warmingwhich can have significant impacts to mankind in the near future. The use of ethanol as the transport fuel canminimize GHG emission. 2. In contrast to crude oil which can one day be depleted, bioethanol can begenerated from renewable sources. Currently, three technologies are involved in bioethanol production. Theseinclude sugar ethanol from sugarcane in Brazil, grain ethanol from corn and wheat in North America andcellulosic ethanol from corn stovers and wheat straws from many countries. Since Canada is not ideal forsugarcane cultivation and the grain ethanol approach has caused a major concern with the perception of foodfor fuel, cellulosic ethanol is the best choice for Canada. However, the enzymes (cellulases and hemicellulases)required to break down cellulose to glucose are relatively complex and costly. New technologies to improve theactivities of these enzymes and to lower the production cost would be needed. In this proposal, a tiny proteinplatform will be engineered to capture different enzymes to form a nano-enzyme complex which can workcooperatively to break down cellulose. These enzymes will be assembled on the platform in a predeterminedorder. Degradation intermediates will diffuse from one enzyme to the other in close proximity. Highly efficientenzymes are selected to incorporate into the platform. All these components will be recombinantly producedusing a microbial factory (Bacillus subtilis, a non-pathogenic bacterium) developed in my laboratory. Thesetechnologies, if successfully developed, will allow cellulosic ethanol production to be truly cost-effective.