Synthetic biology approach to rewire carbon metabolism for efficient photoautotrophic chemical production

气候变化刺激了减少二氧化碳净排放量的努力。为了解决这个问题，将设计光合微生物来回收二氧化碳以生产生物燃料或高价值化学品。本项目将由本科生和研究生参与。他们将获得对生物化学、微生物学和生物工程之间联系的看法。项目成果将与高中和大学的科学和工程教育相结合。辅导将扩大到高中学生，包括那些来自代表性不足群体的学生。这将为他们提供在学术环境中进行研究的机会。该项目将评估一种策略，以改善二氧化碳固定，涉及重新布线碳代谢的蓝藻。蓝藻可以直接将太阳能和二氧化碳转化为生物燃料和生物产品。经过改造的蓝藻可以产生多种化合物，但其产量太低，在商业上没有吸引力。此外，目前大规模的光合作用生产方案依赖于自然光的能量，从而限制了生产的白天时间。所提出的生产系统旨在克服这些限制。以前的研究表明，对二氧化碳固定酶RuBisCO的改进是非常具有挑战性的。因此，本项目将开发一种替代策略，通过增加RuBisCO底物的细胞内水平和将碳通量导向化学生产来改善碳固定。所开发的策略也将作为探索和理解光养行为和代谢的工具。这种方法解决了许多关于蓝藻化学生产的商业可行性的问题。提出的工程蓝藻从二氧化碳中制造化学物质有可能产生更有效、更经济、更可控的生产系统。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Climate change has spurred efforts to reduce net carbon dioxide (CO2) emissions. To address this issue, photosynthetic microorganisms will be engineered to recycle CO2 to produce biofuels or high-value chemicals. Undergraduate and graduate students will participate in this project. They will gain perspective on connections between biochemistry, microbiology, and bioengineering. The project results will be integrated with science and engineering education at the high school and college levels. Mentoring will be extended to high school students, including those from underrepresented groups. This will provide them with the opportunity to perform research in an academic setting. This project will evaluate a strategy to improve CO2 fixation that involves rewiring carbon metabolism in cyanobacteria. Cyanobacteria can directly convert solar energy and CO2 to biofuels and bioproducts. Engineered cyanobacteria can produce a variety of compounds, but the productivities are too low to be commercially appealing. Also, current large-scale photosynthetic production schemes rely on natural sunlight for energy, thereby limiting production to daylight hours. The proposed production system is designed to overcome these limitations. It has been shown previously that improvement of RuBisCO, the CO2 fixation enzyme, is very challenging. Thus, this project will develop an alternative strategy to improve carbon fixation by increasing intracellular levels of the substrate for RuBisCO and directing carbon flux towards chemical production. The strategies developed will also serve as tools for probing and understanding phototrophic behavior and metabolism. This approach addresses many of the issues raised concerning the commercial feasibility of cyanobacterial chemical production. The proposed engineering cyanobacteria to build chemicals from CO2 has the potential to result in more efficient, economical, and controllable production systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.