Performance Modelling of the Bioelectrochemical Glycerol Oxidation by a Co‐Culture of Geobacter Sulfurreducens and Raoultella Electrica

Abstract

Abstract An effectively operating microbial electrolysis cell requires an inexpensive electron donor in combination with a defined and stable electron‐transferring microbial community. Here, a defined co‐culture of Raoultella electrica and Geobacter sulfurreducens was established to generate current during glycerol oxidation. Maximum current densities of 0.20 mA cm −2 and coulombic efficiencies of 21 % were achieved. Glycerol metabolization into acetate by R. electrica and further acetate utilization by the current‐producing G. sulfurreducens were detected. Based on these observations, a physico‐chemical model was established and used to describe quantitatively the relationships between current density, metabolite concentrations and bacterial growth. The competition for acetate between G. sulfurreducens and R. electrica was identified as the major limitation of the system. This detailed quantitative understanding of the physiological interactions opens the door for target‐oriented genetic engineering of the microbes.

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Identifiers

DOI

10.1002/celc.202000027

Journal

ChemElectroChem

Year

2020