Heat treated soil as convenient and versatile source of bacterial communities for microbial electricity generation

Bacterial communities from heat treated soils are shown to be convenient and versatile biocatalysts for hydrogen mediated microbial electricity generation. The isolation of spore forming species by heat pre-treatment allows the growth of robust hydrogen producing bacterial consortia with which electricity can be generated from a large variety of substrates, including complex carbohydrates. The fermentative hydrogen is efficiently oxidized in the microbial medium at electrocatalytic electrodes coated with platinum – poly(tetrafluoraniline) bilayer (Pt-PTFA) composites. Coulombic yields up to 30% with respect to the maximum biological hydrogen yield of 4 moles H2/glucose unit, and maximum current densities of 170–200 mA L−1 were achieved by using chronoamperometric batch and semi-batch experiments.