Understanding and Optimizing Enzyme Efficiency for Cellulose Biodegradation

石油枯竭、能源短缺和环境恶化是重大的全球性问题。我们迫切需要开发将可再生生物质（如农业残留物和林业副产品）转化为更清洁的生物燃料、化学品和其他生物产品的技术。然而，生物质转化的主要瓶颈是高效生物转化酶的生产成本。我的研究项目旨在设计新型细菌，并建立共同培养环境，使生物转化酶的生产更快，更具成本效益，为加拿大工业的清洁能源带来新的机会。一些细菌和真菌可以抵抗极端环境条件，它们可以产生高效的酶，将生物质转化为生物燃料前体和其他产品。厌氧细菌热胞梭菌具有生产高效生物转化酶的巨大潜力：一种复杂的多酶结构，称为纤维素体。我们的研究计划将集中在工程上更有效的生产纤维素的梭状芽胞杆菌菌株。这将大大增加酶的产量，降低生物精炼的成本。然而，虽然梭状芽胞杆菌是纤维素体的优秀生产者和6碳糖的发酵者，但它不能在水解过程中发酵从半纤维素中提取的5碳糖。我们的新方法将引入一种5碳糖发酵细菌，热厌氧细菌saccharolyticus，以创建一个优化的共培养系统，通过同时发酵6碳糖和5碳糖，将大大提高木质纤维素的水解率。通过结合这两种细菌培养，我们将创造一种新的高效酶生产技术。梭状芽胞杆菌和热厌氧细菌的共培养从未进行过，因此我们的研究计划将为一个更大的研究计划设定框架，旨在为生物精炼工业开发更有效的酶生产技术。我们的研究将使所有学员接触到先进的生物技术和设备。他们将获得未来独立工作所需的技术和能力。此外，他们将开发可扩展生物生产的技能、知识和技术，这些技能将对减少我们对化石燃料的依赖、减少温室气体排放和利用加拿大丰富的可再生森林生物质至关重要。

Petroleum depletion, energy shortage, and environmental deterioration are major global issues. We urgently need to develop technologies for converting renewable biomass, such as agricultural residues and forestry byproducts, into cleaner biofuels, chemicals and other bioproducts. However, the major bottle-neck in biomass conversion is the production cost of efficient bioconversion enzymes. My research program aims to engineer new types of bacteria and establish co-culture environments that will make the production of bioconversion enzymes faster and more cost-effective, leading to new opportunities for clean energy in Canadian industry. Some bacteria and fungi that are resistant to extreme environmental conditions are known to produce highly efficient enzymes for converting biomass into biofuel precursors and other products. The anaerobic bacterium Clostridium thermocellum offers great potential for producing highly effective bioconversion enzymes: a complex multienzyme structure called cellulosome. Our research program will focus on engineering more efficient cellulosome-producing strains of Clostridium. This will greatly increase enzyme production, reducing the cost of biorefining. However, while Clostridium is an excellent producer of cellulosomes and fermenter of 6-carbon sugars, it cannot ferment 5-carbon sugars derived from hemicelluloses during hydrolysis. Our novel approach will introduce a 5-carbon sugar-fermenting bacterium, Thermoanaerobacteria saccharolyticus, to create an optimized co-culture system that will greatly increase lignocellulosic hydrolysis rates by simultaneously fermenting 6-carbon and 5-carbon sugars. By combining these two bacterial cultures we will create a new and highly efficient enzyme production technology. The co-culturing of Clostridium and Thermoanaerobacteria has never been undertaken, and our research program will therefore set a framework for a much larger research program that aims to develop more efficient techniques for enzyme production for biorefining industries. Our research will expose all trainees to advanced biotechnology techniques and equipment. They will gain the techniques and abilities required for future independent work. Moreover, they will develop the skills, knowledge and techniques in the development of scalable bioproduction, skills that will be essential in reducing our dependence on fossil fuels, lowering greenhouse emissions and making use of Canada's abundant and renewable forest biomass.