GldA overexpressing-engineered E. coli as superior electrocatalyst for microbial fuel cells

Faster electron transfer between bacteria and electrodes in microbial fuel cells can significantly improve the power density of MFCs for practical applications. A recombinant Escherichia coli (E. coli) strain over-expressing glycerol dehydrogenase (GldA) was engineered as the MFC biocatalyst instead of the natural bacteria. Efficient mediators were produced in the fuel cell with this engineered E. coli resulting in lower polarization and much higher power density than with natural E. coli and E. coli with electro-evolved mediators. For the first time, we demonstrate that engineering E. coli by introduction of appropriate oxidoreductase via gene manipulation can greatly improve the rate of electron transfer. This work provides an efficient and economic approach to biologically engineering bacteria for improving MFC performance. (C) 2009 Elsevier B.V. All rights reserved.