RoL: EAGER: DESYN-C3: Using synthetic energy-harvesting materials at the cell surface to reduce low potential ferredoxins within the cytosol for metabolic applications

Cells utilize many chemical sources of energy. Photosynthetic cells can use sunlight to create chemical bonds that store energy. That energy is used to shuttle electrons around the cell, driving reactions. Despite that, cells cannot utilize external sources of electrical energy directly. If they could utilize electricity as a power source, that would greatly reduce the burden on the cell to create energy on site, freeing it to be directed to more productive activities. This project is an attempt to create a cellular interface that allows that to happen. The external power source will be electricity generated by solar panels. The electricity will drive the production of an amino acid. Graduate students and undergraduates will be trained in advanced bioelectronics research techniques. <br/><br/><br/>The goal of this project is to build a modular cell-material interface that couples external electrical energy sources to the reduction of ferredoxins. The material side of the interface will enable attachment to a range of energy harvesting devices. The cell side will facilitate the transport of low potential electrons across the cell membrane to a ferredoxin, which will then be used to enhance the production of a reduced metabolite, the amino acid cysteine. The first objective is to engineer efficient electron transfer across the membrane. A high-throughput selection will be used to couple the growth of Escherichia coli to the electron cycling efficiency of low potential ferredoxin (Fd) electron carriers. The second objective is to build a biocompatible material (an organic electrode) that functions as a cell-surface coupling module. Diffusible mediators will be incorporated into the electrode and the effectiveness of organic phospholipids in mediating long-range electron transfer will be examined. The final objective is to use biological-organic hybrids to increase metabolic pathway yields and characterize electron transfer efficiencies. The interfaces arising from this project will be modular, and potentially useful in powering natural and synthetic cell processes.<br/><br/>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.