Screening and Selection of Ferric Reducing Bacteria by Electrical Current for Microbial Fuel Cell

The efficiency of microbial fuel cell (MFC) performance depends on the competence of microorganisms on being an essential role in primarily converting organic compound into electricity. In this study, the possibility of using electrical current to select electrochemical active bacteria from sub-sediment for use in MFC was conducted. By using an alternating current (AC) of 0.6-12 mA and selective media, 16 Gram-positive ferric reducing bacteria (GP-FRB), 15 Gram-negative ferric reducing bacteria (GN-FRB) and 9 Gram-negative non FRB (GN-nonFRB) were characterized. GN-FRB and GP-FRB were obtained from the current of 0.6-6 and 9-12 mA, respectively. After tested in MFC, GN-FRB had a greater current density and power density than those from GN-nonFRB and GP-FRB. However, the greatest voltage was obtained from GP-FRB, followed by those of GNnonFRB and GN-FRB, respectively. The highest current and power density of 13.33 mA/m2 and 0.32 mW/m2, respectively were from GN-FRB namely KL14 which was identified later as Proteus sp. This research could contribute a promising method for screening and selection of ferric reducing bacteria using electrical current. MFC inoculated with our selected bacteria could be a model for next study in wastewater treatment.