Electrobioreactor for Bioconversions
Nearly 20% of known oxidoreductases require cofactors to supply stoichiometric quantities of reducing equivalents. For the majority of these oxidoreductases, NAD(P)H is the required cofactor. Since the total pool of intracellular NAD(P)H and NAD(P)+ is relatively small, cofactor recycling is needed in the order of thousands to millions of cycles. We are collaborating with Prof. Mattheos Koffas to develop an electrobioreactor for enzymatic transformations and ultimately leading to fermentation-based biotransformations. As shown in Figure BF-4, we are developing an electrochemical bioreactor that can be used both for enzymatic reactions and fermentation. Using this set-up, we will overcome unproductive NAD(P)H isomers produced by electrochemical reduction using the enzyme renalase, which naturally salvages non-biologically relevant NAD(P)H isomers leading back to the oxidized NAD(P)+ for further use [Morrison et al. Biotechnol. Adv. 36, 120-131 (2018)].
Figure BF-4. Electrochemical reactor for the synthesis of NAD(P)H for reduction of oxidized substrates. The figure illustrates the overall electrochemistry and general arrangement of the biocatalytic process. Externally-driven current flow provides reducing power to a redox enzyme via the reduction of the redox cofactor NAD(P)+ to NAD(P)H, thereby driving the biocatalytic conversion of a substrate to a reduced product. An optional, generic electron transport mediator can shuttle electrons between the cathode and NAD(P)+ [Morrison et al. Biotechnol. Adv. 36, 120-131 (2018)].
Mattheos Koffas – Rensselaer Polytechnic Institute
William Armiger – BiochemInsights, Inc.