Deciphering simultaneous bioelectricity generation and reductive decolorization using mixed-culture microbial fuel cells in salty media

This first-attempt study unveiled interactive characteristics of simultaneous bioelectricity generation and reductive decolorization (SBG&RD) of reactive blue 160 (RBul60) in air-cathode single chamber microbial fuel cells (MFCs) containing salty LB media using halotolerant Exiguobacterium acetylicum dominant mixed culture. After ca. 1 year serial acclimatization in salt and/or RBul 60 bearing media, the microbes could successfully express electrochemically stable SBG&RD capabilities in salty MFCs. Electrochemical impedance spectroscopy and cyclic voltammograms revealed that supplementation of RBul60 significantly promoted current production in salty MFC. Combined interaction of the anodic biofilm, RBul60 and LB medium apparently controlled the performance of SBG&RD for long-term operation. Nyquist plot with impedance vector progressively formed a semicircle with a minimum radius, indicating that electrochemically-active microorganisms in salty MFC were stably propagated for long-term bioelectricity generation. (C) 2013 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.