Comparison of Escherichia coli and anaerobic consortia derived from compost as anodic biocatalysts in a glycerol-oxidizing microbial fuel cell

Using glycerol from biodiesel production as a fuel in a microbial fuel cell (MFC) will generate electricity and value-added by-products from what is currently considered waste. This research screened Escherichia coli W3110 (ATCC 27325) and a mixed culture enriched from compost (AR2) as anodic biocatalysts in a mediatorless glycerol-oxidizing MFC. In an H-type MFC, the mixed culture AR2 biocatalyst produced a maximum power density of 11.7 mW m−2 compared to 9.8 mW m−2 using E. coli W3110 as the anodic catalyst. In batch operation of the fuel cell, the mixed culture AR2 was able to anaerobically consume 29 g/L of glycerol compared to only 3.3 g/L using the E. coli strain. The mixed culture was also shown to concurrently produce 1,3-propanediol, a value-added product, and electricity from a pure glycerol feedstock in an MFC.