About This Project

This project aims to create a bioelectrochemical interface using enzymes and bacterial protein nanowires. The nanowires facilitate direct electron transfer between electrodes and biological reaction sites. This enhances microbial electron transfer efficiency, with applications in sustainable energy, remediation, and biosynthesis. The focus is on the design and characterization of these enzyme-nanowire assemblies, laying groundwork for new biohybrid systems.

Ask the Scientists

What is the context of this research?

Addressing climate change requires both reducing and removing atmospheric CO2. While awareness grows, most industries still emit more CO2 than they capture. For carbon capture to scale quickly, it must be economically viable—turning airborne carbon from a liability into a resource. Biology, using its enzymatic nanomachines, offers precise and unparalleled molecular control perfectly suited to the task of converting CO2 into valuable products. However, current industrial bioprocesses rely on feedstocks like sugar, agricultural waste, or high-energy gases to provide power to biological systems. These choices present problems including displacement of arable land, transport costs, and low productivity compared to competing petrochemical processes.

What is the significance of this project?

Bioelectrochemical systems present a promising solution to this dilemma, leveraging electricity to produce biological inputs on-demand. For example, these systems often tap into 'artificial photosynthesis' to split water and produce energy intermediates. More recently a route called direct electron transfer (DET) has gained recognition, whereby electrons from a conductor are transferred directly to bacteria. We envision taking advantage of this phenomenon by plugging enzymes into the grid to harness surplus electricity, bridging the gap between the industrial and biological worlds. Yet, challenges persist. The mechanisms of DET were until recently not well understood, and as a result are still harnessed inelegantly, yielding low practical efficiencies.

What are the goals of the project?

Recent insights into bacterial electron transfer along with the emerging capabilities of protein design tools give rise to a significant opportunity. The primary objective of this proposal is to design a binding site for the interaction of a bacterial nanowire protein with a redox-active carbon fixation enzyme. A secondary goal is functional validation of desired activity with detection of increased CO2 fixation rate. Achieving these goals sets the stage for a paradigm shift: directly channeling renewable electric power into diverse biocatalytic reactions. This could usher in a new era of biomanufacturing, and even the potential of built-to-purpose enzymes taking advantage of this newfound source of power to catalyze previously inaccessible products directly from CO2.