STTR Phase I: Processing Genetically Engineered Biomass to Obtain Optimal Enzymatic Digestion of Cell Wall Polysaccharides in Cellulosic Biofuel Production

这个小企业技术转移第一阶段项目将展示提高木质纤维素酶性能的方法，这些酶被改造成用于生产纤维素乙醇的作物原料。目前的原料转化过程使用稀酸、高温“预处理”步骤，使纤维素和半纤维素等多糖底物更容易被生物反应器产生的糖酵解酶（“糖酶”）所获取，这些酶在后面的步骤中添加。这种糖酶最近已在作物原料中生产，作为降低酶成本的一种手段。由于预处理的热量和酸可以使植物产生的糖酶变性，因此需要开发一种材料工艺流程，通过预处理过程进入下游糖化过程来保持糖酶的活性。该项目将描述在整个纤维素乙醇生产过程中激活和保持内源性糖酶活性的条件。该项目的成功完成将降低从各种农业残留物和专用能源作物中生产纤维素乙醇的成本。这项技术将有助于实现生物能源作物工程的巨大潜力，使原料加工过程的改进对这种新型能源的商业化是必要的。通过提高植物酶的使用效率，可以降低预处理和下游糖化的成本，从而促进作为可再生运输燃料的纤维素乙醇的扩大生产，减少二氧化碳排放和化石燃料的污染，促进能源独立，提高农村和农场收入。

This Small Business Technology Transfer Phase I project will demonstrate methods of increasing the performance of lignocellulosic enzymes engineered into crop feedstocks that are used to produce cellulosic ethanol. Current feedstock conversion processes use a dilute acid, high temperature "pretreatment" step to make polysaccharide substrates such as cellulose and hemicellulose more accessible to bioreactor produced glycolytic enzymes, "glycozymes," that are added at a later step. Such glycozymes have recently been produced in crop feedstocks themselves as a means of reducing enzyme costs. Since pretreatment heat and acid can denature plant-produced glycozymes, there is a need to develop material process flows that preserve glycozyme activity through the pretreatment process into downstream saccharification. This project will characterize conditions for activating and preserving endogenous glycozyme activity throughout the cellulsic ethanol production process. Successful completion of the project will reduce the cost of producing cellulosic ethanol from a wide variety of agricultural residues and dedicated energy crops. This technology will help realize the enormous potential of engineered bioenergy crops by making feedstock processing improvements necessary for the commercialization of this novel energy resource. By increasing the efficient use of plant-produced enzymes, the costs of pretreatment and downstream saccharification can be reduced, thereby facilitating expanded production of cellulosic ethanol as a renewable transportation fuel, reducing CO2 emissions and pollution from fossil fuels, fostering increased energy independence, and raising rural and farm incomes.