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Break

Redox imbalance is a critical limitation to optimizing yield in many industrial biomanufacturing settings, where metabolic flux is often redirected to low yield pathways to regenerate reduction equivalents, and the knockout of these competing pathways destabilizes the distribution of intracellular electron carriers (i.e., NAD(P)H: NAD(P)+). Further, as protein engineering as a discipline matures to meet the potential of increasingly complex organic synthesis strategies, such as the use of enzymatic cascades or other redox equivalent dependent reactions (C-H activations, reductive aminations, etc), efficient cofactor regeneration is necessary to achieve complex stereochemical conformations in a variety of therapeutics and value-added products. Microbial electrosynthesis (MES) using electroactive biocatalysts capable of extracellular electron transfer (EET) offers a solution to overcome redox imbalance of complex biosynthesis strategies, but there is little knowledge on relevant pathways and methods to engineer proteins implicated with electrotrophs. MES represents an appealing and advantageous approach to optimizing yield over other proposed solutions; bioreactor gas sparging requires fine-tuned control of gas supply and reactor conditions to support optimal H2 solubility, and is not viable for many cell-free processes due to reactive oxygen species (ROS) formation. Other methods of regenerating reduction equivalents remain to have other drawbacks, such as the cost of enzyme production and immobilization, and the cost and toxicity of chemical catalysts. The development of this technology to address reaction chemistries that are currently economically nonviable is well-timed due to the convergence of renewable energy paradigm shifts and the rise of a bioeconomy to support sustainable enterprise. Herein we describe methods to computationally model and predict electroactivity in microorganisms to enable the efficient engineering of electricity driven biomanufacturing. To demonstrate the potential of this technology, technoeconomic models for production of CO2 derived chemicals are constructed to delineate improvements to technology readiness levels (TRL’s) given the effective implementation of commercial MES.