Tailored cell embedment for enhanced continuous microbial electrosynthesis (Conti-eBiotech)

The aim of this proposal is to develop new strategies for high-performance microbial electrosynthesis (MES) based on the embedment of microorganisms with very poor biofilm formation ability into conductive and functional polymer composites acting – electrode-attached – as artificial electroactive biofilms. Tailored biocomposites will be developed based on conductive matrices containing the respective bacterial cells, conductive additives and potential functional components such as hydrogen evolution catalysts. The properties of the biocomposites can be selectively tailored to facilitate long distance microbial extracellular electron transfer (EET) and to improve process stability. Cell embedding will also provide protection against stress factors like pH and oxygen, thus increasing biological activity. This approach will provide the possibility to immobilize microorganisms with a defined biomass concentration at the cathode. Furthermore, the previous disadvantage of a long-process-phase for the formation of a viable biofilm at the cathode will be overcome. The performance of the embedding method to be developed here will be investigated by a comparative study based on two functionally different, well-studied and established model organisms, Shewanella oneidensis and Clostridium ljungdahlii, in planktonic chemostat and electrode-associated retentostat cultivation, to generate reaction kinetic parameters. With these parameters a product formation model for the cathodic MES will be developed based on the combination of biochemical and electrochemical model terms. The generated knowledge will lay the foundation for further considerations for the scale-up of MES processes, improvements of the reactor performance as well as energetic aspects.

Partners

Technische Universität Braunschweig

Universität Greifswald

People

Prof. Dr. Rainer Krull

Technische Universität Braunschweig

Prof. Dr. Uwe Schröder

Universität Greifswald

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