Final Report: Bioelectrochemical Process Development

Abstract

Work performed under the Independent Research and Development project ''Bioelectrochemical Process Development'' using Shewanella Oneidensis MR-1 henceforth MR-1, a model dissimilitory metal reducing (DMRB) bacteria successfully demonstrates the following: MR-1 transfers electrons by hydrogen oxidation to solid phase electrodes; MR-1 can act as an electron transfer agent when attached to a solid metal electrode surface - a modified electrode has been developed and tested; MR-1 transfers electrons from solution to a solid electrode. DMRB grow by transferring electrons to insoluble metals. When bacteria oxidize organic compounds or hydrogen this results in electron flow from the bacterial cell for the purpose of cellular energy production. Extracellular electron transfer to solid terminal electron acceptors permits coupling this oxidation process to electrodes. As a result, detection of organic compounds and hydrogen can be accomplished by bacterial contact to an electrode. The authors have designed a process that incorporates bacterial cells onto electrodes for the purpose of hydrogen detection. In addition, this type of bio-sensor also responds to the presence of FE III thereby providing potential utility as a Fe III sensor. Immediate uses of this technology include in-situ detection and quantification of organic compounds and hydrogen in the subsurface that provide energy for growth of indigenous bacteria.