Bridging Living Microbes and Electrodes with Biosynthetic and Biological Polymers

Ongoing discoveries with exoelectrogenic microbes have inspired the latest developments in whole-cell energy devices. This devicees rely on the effective interfacing of living microbes and electrodes for bioelectricity generation. A combination of materials engineering and biological engineering has thusfar contributed to record-breaking device performances in microbial fuel cells and living photovoltaics. These advancements have largely focused on the expression of protein-based electron conduits in bionengineered microbes [1], conductive polymer-based electrodes [2-3] and nanobionics [4] for enhancing device performances.<br/><br/>This presentation focuses on complementary approaches that exploit biosynthetic material characteristics. We explore the development of biosynthesizable electrodes based on biological polymers [5-6] as well as soluble biological mediators [7]. This presentation also examines the development andoptimization of solid-state electrode constructs with enhanced charge-extraction capabilities. Finally, we discuss recent techniques inspired by synthetic electronic laboratories. These advancements establish new benchmarking techniques fore electrobiological characterization that have been lacking in the field.<br/><br/><br/>[1] Mouhib, M.; Reggente, M.; Lin, L.; Schurgers, N.; Boghossian, A.A. Extracellular electron transfer pathways to enhance the electroactivity of modified Escherichia coli Joule, 7, 2092–2106 (2023).<br/><br/>[2] Reggente, M.; Politi, S.; Antonucci, A.; Tamburri, E.; Boghossian, A.A. Design of Optimized PEDOT-Based Electrodes for Enhancing Performance of Living Photovoltaics Based on Phototropic Bacteria, Adv Mater Technol. 5, 1900931 (2020).<br/><br/>[3] Roullier, C.; Reggente, M.; Gilibert, P.; Boghossian, A.A. Polypyrrole Electrodes Show Strain-Specific Enhancement of Photocurrent from Cyanobacteria, Adv Mater Technol. 8, 2201839 (2023).<br/><br/>[4] Antonucci, A.; Reggente, M.; Roullier, C.; Gillen, A.J.; Schuergers, N.; Zubkovs, V.; Lambert, B.P.; Mouhib, M.; Carata, E.; Dini, L.; Boghossian, A.A. Carbon nanotube uptake in cyanobacteria for near-infrared imaging and enhanced bioelectricity generation in living photovoltaics, Nat Nanotech. 17, 1111–1119 (2022).<br/><br/>[5] Labarile, R.; Vona, D.; Varsalona, M.; Grattieri, M.; Reggente, M; Comparelli, R.; Farinola, G.M.; Fischer, F.; Boghossian, A.A.; Trotta, M. In vivo polydopamine coating of Rhodobacter sphaeroides for enhanced electron transfer, Nano Res. 17, 875−881 (2024).<br/><br/>[6] Reggente, M.; Roullier, C.; Mouhib, M.; Brandl, P.; Wang, H.; Tacconi, S.; Mura, F.; Dini, L.; Labarile, R.; Trotta, M.; Fischer, F.; Boghossian, A.A. Polydopamine-coated photoautotrophic bacteria for improving extracellular electron transfer in living photovoltaics, Nano Res. 17, 866–874, (2024).<br/><br/>[7] Mouhib, M; Reggente, M;. Boghossian, A.A. Implementation of a flavin biosynthesis operon improves extracellular electron transfer in bioengineered Escherichia coli, bioRxiv 10.1101/2022.12.31.522390