Effects of inoculation sources on the enrichment and performance of anode bacterial consortia in sensor typed microbial fuel cells

Abstract

Microbial fuel cells are a recently emerging technology that promises a number of applications in energy recovery, environmental treatment and monitoring. In this study, we investigated the effect of inoculating sources on the enrichment of electrochemically active bacterial consortia in sensor-typed microbial fuel cells (MFCs). Several MFCs were constructed, operated with modified artificial wastewater and inoculated with different microbial sources from natural soil, natural mud, activated sludge, wastewater and a mixture of those sources. After enrichment, the MFCs inoculated with the natural soil source generated higher and more stable currents (0.53±0.03 mA), in comparisons with the MFCs inoculated with the other sources. The results from denaturing gradient gel electrophoresis (DGGE) showed that there were significant changes in bacterial composition from the original inocula to the enriched consortia. Even more interestingly, <em>Pseudomonas</em> sp. was found dominant in the natural soil source and also in the corresponding enriched consortium. The interactions between <em>Pseudomonas</em> sp. and other species in such a community are probably the key for the effective and stable performance of the MFCs.