CAREER: Engineering redox metabolism using unnatural cofactors

化学品可以利用微生物从可再生资源合成。这种方法可以帮助化学工业变得更加可持续。这种策略广泛实施的一个主要障碍是电池部分的低生产效率。克服这个问题的标准方法是通过细胞代谢来改变碳的流动。在这个项目中，电子通过电池的流动将被调整。这将通过制造人造电子穿梭分子来实现，这种分子被称为辅因子。这是一个创新的策略。它可以大大提高利用微生物制造化学品的效率。外联活动将与研究任务结合起来。因此，该项目代表了一种尝试：(1)允许生物制造更好地满足国家对能源、食品、商品和药品的需求；（ii）促进STEM的本科和研究生教育；（iii）激励奥兰治县的女高中生从事工程职业。分解代谢和合成代谢共存而不受干扰，因为每一个都有单独的氧化还原辅助因子。第三，独立的氧化还原辅助因子可以使特定途径与核心代谢隔离。提高生产力可以通过建立新的氧化还原辅助因子和进化的酶在产品途径中只需要该辅助因子来实现。本项目将建立烟酰胺单核苷酸（NMN）作为第三个氧化还原辅助因子。这将通过一个三步实验计划来完成。首先，将开发用于nmn依赖电子电路工程的高通量选择平台。然后，大肠杆菌和酿酒杆菌能够过量生产NMN的菌株将被构建。最后，NMN依赖性甲酸脱氢酶将被设计成独立于宿主代谢背景提供NMN还原能力。这些目标的成功完成将导致两种工业相关菌株能够作为nmn依赖途径和产品的基础。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。

Chemicals can be synthesized from renewable resources using microbes. This approach could help the chemical industry become more sustainable. A major hurdle to the widespread implementation of this strategy is low production efficiency on the part of the cells. The standard approach to overcome this has been to modify the flow of carbon through cell metabolism. In this project, the flow of electrons through the cell will be adjusted. This will be accomplished by creating artificial electron shuttle molecules, known as cofactors. This is an innovative strategy. It could greatly increase the efficiency of using microbes to manufacture chemicals. Outreach activities will be integrated with the research tasks. As a result, the project represents an attempt to (i) allow biomanufacturing to better meet the Nation's needs for energy, food, commodities, and medicine; (ii) contribute to undergraduate and graduate education in STEM; and (iii) motivate female high school students in Orange County to pursue a career in engineering.Catabolism and anabolism co-exist without interference because each has a separate redox cofactor. A third, independent redox cofactor may enable a specific pathway to be insulated from core metabolism. Increased productivity might be achieved by establishing the new redox cofactor and evolving enzymes in the product pathway to require that cofactor exclusively. This project will establish nicotinamide mononucleotide (NMN) as the third redox cofactor. This will be accomplished through a three-step experimental plan. First, high-throughput selection platforms for engineering of NMN-dependent electron circuits will be developed. Then, strains of E. coli and S. cerevisiae capable of overproduction of NMN will be constructed. Finally, NMN-dependent formate dehydrogenase will be engineered to deliver NMN reducing power independently of the host's metabolic background. Successful completion of these objectives will result in two industrially-relevant strains capable of acting as a chassis for NMN-dependent pathways and products.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.