Miehle, MaximilianMaximilianMiehleGescher, JohannesJohannesGescherHorn, HaraldHaraldHornHille-Reichel, AndreaAndreaHille-Reichel2026-06-302026-06-302026-06-15Results in Engineering 31: 111572 (2026)https://hdl.handle.net/11420/63708Bioelectrochemical systems (BES) represent a promising technology for the production of energy, energy carriers, and chemicals; however, their implementation in industrial applications faces significant challenges related to scalability. In this study, we introduce a novel, scalable, single-chamber BES in which the working electrode is realised as a packed bed of electrically conductive equal-sized spheres made from a graphite-polymer composite. The reactor has a total volume of 3.56 L and a packed bed volume of 1.66 L with an electrode surface area of 1.06 m². A model microbial electrolysis / electro-fermentation of lactate to acetate was catalysed by the exoelectrogenic bacterium Shewanella oneidensis , achieving a maximum current density of 430 mA m^-2 at an anode potential of 300 mV relative to the standard hydrogen electrode.en2590-12302026Elsevierhttps://creativecommons.org/licenses/by/4.0/Electro-fermentationMicrobial electrolysis cell (MEC)Packed-bed BES reactorShewanella oneidensisTechnology::660: Chemistry; Chemical Engineering::660.6: BiotechnologyJournal Article10.1016/j.rineng.2026.11157210.15480/882.17400