SBIR Phase I: Development of microalgae for commercial hydrogen biofuels

该小型企业创新研究（SBIR）第一阶段项目将采用创新方法对藻类进行代谢工程改造，并实现中到大规模的低成本无碳制氢。实现高氢产量的一种方法涉及使用绿色藻类，其通过利用阳光分解水来产生氢。 绿色藻类中的氢产生是基于高活性的氢形成酶（氢化酶）的存在。 因此，在藻类中生产氢的方法已经利用了防止氧的产生的机制，这使氢化酶失活。 然而，这些方法，在光厌氧硫剥夺的基础上，导致产量低。 本文的研究将评估应用一种新策略的可行性，以指导代谢通量朝向在硫的存在下的氢生产。 在第一阶段，编码氢化酶和成熟蛋白的嵌合基因将被引入藻类基因组。 将评估工程菌株的氢化酶活性，并确定在典型的缺硫和含硫条件下的产氢水平。 我们预计，这一创新策略将使氢化酶以活性形式大量积累，从而将对电子供体的竞争转移到有利于氢化酶的位置，以持续高速率产生氢气。该项目更广泛的影响/商业潜力是对我们国家减少使用外国石油的能力的影响，并创造许多新的就业机会。该项目将扩大我们对藻类中氢化酶的功能和光发电氢的基本理解。这项创新将使具有成本效益、可再生和环境清洁的氢气的商业化生产成为可能。目前，商业氢气生产主要依赖电力和二氧化碳排放。如果成功，所提出的方法将提供一个商业化的制氢过程，该过程将发电并封存二氧化碳。丰富的低成本、可再生氢应该会扩大氢市场，以发电和为车辆提供燃料。仅20万公顷使用改良菌株的藻类池塘就可以取代20%的进口原油。因此，该项目将通过加强国家能源安全产生巨大的商业影响。此外，这项技术将通过发展藻类养殖来促进美国农业生产的多元化和可持续性，而藻类养殖不需要耕地。这项技术可能会产生理论上最生态清洁的生物燃料。 因此，该项目可以通过减少碳足迹和促进农村地区的经济多样化产生巨大的社会影响。

This Small Business Innovation Research (SBIR) Phase I project will employ an innovative approach to metabolically engineer algae and enable low-cost, carbon-free hydrogen production at medium to large scale. One approach to achieving high hydrogen production involves the use of green algae, which produce hydrogen by using sunlight to split water. Hydrogen production in green algae is based on the existence of highly active hydrogen-forming enzymes, hydrogenases. Accordingly, the processes for hydrogen production in algae have utilized mechanisms to prevent the generation of oxygen, which inactivates hydrogenase. However, these processes, based on anaerobic sulfur-deprivation in light have resulted in low yields. The investigation herein will assess the feasibility of applying a novel strategy to direct metabolic flux toward hydrogen production in the presence of sulfur. During Phase I, chimeric genes encoding a hydrogenase and maturation proteins will be introduced into the algae genome. Engineered strains will be evaluated for hydrogenase activity, and hydrogen production levels under typical sulfur-deprivation and sulfur-containing conditions will be determined. We anticipate that this innovative strategy will enable abundant accumulation of hydrogenase in an active form that shifts competition for an electron donor in favor of hydrogenase to continuously generate hydrogen at high rates.The broader impact/commercial potential of this project is the impact on our nation's ability to reduce its use of foreign oil and create many new jobs. This project will expand our fundamental understanding of the function of hydrogenase and light-powered generation of hydrogen in algae. The innovation will enable commercial generation of cost-effective, renewable, and environmentally clean hydrogen. The commercial hydrogen production currently is burdened by major dependence on electricity and carbon dioxide emission. The proposed approach, if successful, provides a commercial process for hydrogen production, which will generate electricity and sequester carbon dioxide. The abundance of low-cost, renewable hydrogen should expand hydrogen markets to generate electricity and fuel vehicles. Just 200,000 ha of algal ponds using improved strains could displace 20% of imported crude oil. Thus, the project will have great commercial impact by enhancing national energy security. Moreover, this technology will promote diversification and sustainability of agricultural production in the U.S. through development of algae farming, which will not require arable land. Potentially, this technology will produce the most ecologically clean biofuel theoretically available. Therefore, this project could have great social impact by decreasing carbon footprint and promoting economic diversification in rural areas.