SBIR Phase II: Development of microalgae for commercial hydrogen biofuels

这个小企业创新研究（SBIR）第二阶段项目建议使用一种创新的方法来代谢工程藻类，这将使低成本、无碳的氢气生产成为可能。微藻产氢的代谢途径受到严格调控。氢气生产的过程模型是基于厌氧硫剥夺，防止产生氧，使氢化酶失活。然而，氢气的产量太低，不适合经济的商业过程。由于保护产氢的代谢途径复杂，产氢速率难以提高。该项目将继续进行代谢工程，以增加氢化酶的电子可用性，并为可扩展和商业上可行的氢生产开发稳定的菌株。提出的研究将扩大对以下方面的基本认识：1)富硫条件下和缺硫条件下藻类氢化酶的电子流；2)氢化酶成熟的要求；3)保护氢化酶不受氧的要求。如果该项目成功，其更广泛的影响/商业潜力将是商业生产具有成本效益、可再生和环境清洁的氢气，这将极大地影响美国减少对外国石油使用的能力，并创造许多新的就业机会。目前，商业制氢主要依赖电力和二氧化碳排放。这个提议的方法为氢气生产提供了一个商业化的过程，既可以发电，又可以隔离二氧化碳。大量低成本、可再生的氢将扩大氢市场，用于发电和为汽车提供燃料。使用改良品种的20万公顷藻类池塘可以取代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不需要耕地的藻类养殖，促进美国农业生产的多样化和可持续性。这项技术有可能生产理论上最生态清洁的生物燃料，并可能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 II project proposes to use an innovative approach to metabolically engineer algae that will enable low-cost, carbon-free hydrogen production at medium to large scale. The metabolic pathway for hydrogen production in microalgae is tightly regulated. Process models for hydrogen production are based on anaerobic sulfur-deprivation preventing generation of oxygen, which inactivates hydrogenases. However, hydrogen yields are too low for an economical commercial process. Hydrogen production rates are difficult to improve due to complicated metabolic pathways guarding hydrogen production. Novel proprietary Chlamydomonas strains with synthetic genes for hydrogenase and maturation proteins were created and proven in Phase I. This project will continue the metabolic engineering to increase electron availability for hydrogenase and develop stable strains for scalable and commercially viable production of hydrogen. The proposed research will expand fundamental understanding of: 1) electron flow toward algal hydrogenases under sulfur-rich conditions and sulfur-deprivation, 2) requirements for maturation of hydrogenases, and 3) requirements to protect hydrogenases from oxygen. The broader impact/commercial potential of this project, if successful, will be the commercial generation of cost-effective, renewable, and environmentally clean hydrogen that could greatly impact the nation's ability to reduce its use of foreign oil and create many new jobs. The commercial hydrogen production currently is burdened by major dependence on electricity and carbon dioxide emission. The proposed approach provides a commercial process for hydrogen production that 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, and could have great social impact by decreasing the carbon footprint and promoting economic diversification in rural areas.