Biotechnology Letters, Vol.32, No.12, 1837-1845, 2010
Towards an integrated system for bio-energy: hydrogen production by Escherichia coli and use of palladium-coated waste cells for electricity generation in a fuel cell
Escherichia coli strains MC4100 (parent) and a mutant strain derived from this (IC007) were evaluated for their ability to produce H-2 and organic acids (OAs) via fermentation. Following growth, each strain was coated with Pd(0) via bioreduction of Pd(II). Dried, sintered Pd-biomaterials ('Bio-Pd') were tested as anodes in a proton exchange membrane (PEM) fuel cell for their ability to generate electricity from H-2. Both strains produced hydrogen and OAs but 'palladised' cells of strain IC007 (Bio-Pd-IC007) produced similar to threefold more power as compared to Bio-Pd-MC4100 (56 and 18 mW respectively). The power output used, for comparison, commercial Pd(0) powder and Bio-Pd made from Desulfovibrio desulfuricans, was similar to 100 mW. The implications of these findings for an integrated energy generating process are discussed.