CAREER: A novel microbial electrosynthesis platform built on a model electron transfer pathway

当今社会面临的两大挑战是从可持续材料中生产燃料和化学品，以及储存太阳能和风能技术产生的能源。这两项壮举都是由细菌在一个称为微生物电合成的过程中实现的，在这个过程中，细菌将二氧化碳转化为燃料和化学品，使用电力作为动力源。该项目将开发具有改进的电合成能力的细菌。该项目还将培养合成生物学的研究生和本科生成为这一新兴领域的下一代科学家。教育工作扩展到成人和小学观众，以扩大对合成生物学的理解。拟议的工作采取了一种新的方法，使微生物电合成，通过开发一个平台，在良好的表征生物体，适合基因工程的电力吸收。初步结果表明，在电化学活性细菌Shewanella oneidensis MR-1中，乙偶姻电驱动还原为2，3-丁二醇。这是有史以来第一次证明，电力可以用来产生细胞内的还原能力，通过一个明确的生化途径。在这些令人兴奋的结果的基础上，提出了提高该系统中电子转移速率的工作，将该系统与大肠杆菌中燃料和化学品的生产联系起来，并确定电子吸收所需的天然途径。这将产生一个可推广的平台，可用于驱动广泛的还原反应，包括二氧化碳固定，并为进一步的研究提供坚实的基础。该奖项反映了NSF的法定使命，并被认为是值得支持的，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。

Two major challenges facing society today are generating fuels and chemicals from sustainable materials, and storing energy produced by solar and wind technologies. Both feats are achieved by bacteria in a process called microbial electrosynthesis, in which bacteria convert carbon dioxide into fuels and chemicals using electricity as a power source. This project will develop bacteria with improved electrosynthesis capability. This project will also train graduate and undergraduate students in synthetic biology to be the next generation of scientists in this emerging field. The educational efforts extend to adult and primary school audiences, to broaden understanding of synthetic biology. The proposed work takes a novel approach to enable microbial electrosynthesis by developing a platform for electricity uptake in well-characterized organisms that are amenable to genetic engineering. Preliminary results demonstrate electricity-driven reduction of acetoin to 2,3-butanediol in the electrochemically-active bacterium Shewanella oneidensis MR-1. This is the first-ever demonstration that electricity can be used to generate intracellular reducing power through a defined biochemical pathway. Building on these exciting results, work is proposed to enhance electron transfer rates in this system, connect the system to production of fuels and chemicals in Escherichia coli, and identify the native pathways necessary for electron uptake. This will result in a generalizable platform that can be used to drive a wide range of reduction reactions, including carbon dioxide fixation, and provide a strong foundation for further research.This CAREER award is supported by the Division of Chemical, Bioengineering, Environmental and Transport Systems and the Division of Molecular and Cellular Biosciences.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.