Microbial electrosynthesis (MES) allows utilizing electric power, hence electrons, as reactants for the microbial production of chemicals. With their potential for autotrophic bioprocesses, especially strict anaerobic microorganisms for cathodic MES (also known as electroautotrophs) have attracted significant research interest in the last decade. To date, the focus still is on the investigation of the microbial catalyst and possible bioproduction routes and products. However, for MES no common bioprocess infrastructure is established and a wide variety of reactors that allow no comparison is used. In most lab scale systems, physiological stressors, e.g. from oxygen evolving at the anode, lead to detrimental effects and hence a lower MES performance. Therefore, a functional and scalable bioprocess infrastructure is urgently needed for paving the way of MES to industrial implementation. For conducting this research, partners HKI and UFZ build on their shared excellent foundation on microbial electrochemistry and technology.

ESCAPE 2.0 is built around the continuous mirroring of reactor-specific and reaction-specific performance parameters and indicators to allow establishing an electrobioreactor platform that provides a wide process window for MES by electroautotrophs. C. ljungdahlii – as a model acetogen and a promising anaerobic bioproduction platform – will serve as a example electroautotroph. A deep physiological stress characterization of the catalyst will be performed followed by the development of specific biosensors, as well as an expansion in C. ljungdahlii product profile via rational-designed molecular and process engineering. Components (e.g. electrode reactions) as well as architecture (e.g. chicanes or gas-recycling) of electrobioreactors will be designed and engineered in a combined
modelling- and experimental-based approach. The electrobioreactors will be benchmarked using the model electroautotroph including full carbon and electron balances. Finally, ESCAPE 2.0 will lead to electrobioreactors at 1-L or even up to 3-L scale that allow the operation and deep physiological characterization of strictly anaerobic MES at different modes of operation (e.g. batch or flow-mode). The final electrobioreactors will also be tested with other electrotrophs and
will be made available for other partners from the SPP consortium.