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A defined co‐culture of Geobacter sulfurreducens and Escherichia coli in a membrane‐less microbial fuel cell
Author(s) -
Bourdakos Nicholas,
Marsili Enrico,
Mahadevan Radhakrishnan
Publication year - 2014
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.25137
Subject(s) - microbial fuel cell , geobacter sulfurreducens , wastewater , microorganism , geobacter , volatile suspended solids , sewage treatment , bacteria , biology , escherichia coli , energy source , microbiology and biotechnology , pulp and paper industry , chemistry , environmental chemistry , biofilm , chemical oxygen demand , environmental engineering , biochemistry , environmental science , ecology , renewable energy , electrode , gene , anode , genetics , engineering
Wastewater‐fed microbial fuel cells (MFCs) are a promising technology to treat low‐organic carbon wastewater and recover part of the chemical energy in wastewater as electrical power. However, the interactions between electrochemically active and fermentative microorganisms cannot be easily studied in wastewater‐fed MFCs because of their complex microbial communities. Defined co‐culture MFCs provide a detailed understanding of such interactions. In this study, we characterize the extracellular metabolites in laboratory‐scale membrane‐less MFCs inoculated with Geobacter sulfurreducens and Escherichia coli co‐culture and compare them with pure culture MFCs. G. sulfurreducens MFCs are sparged to maintain anaerobic conditions, while co‐culture MFCs rely on E. coli for oxygen removal. G. sulfurreducens MFCs have a power output of 128 mW m −2 , compared to 63 mW m −2 from the co‐culture MFCs. Analysis of metabolites shows that succinate production in co‐culture MFCs decreases current production by G. sulfurreducens and that the removal of succinate is responsible for the increased current density in the late co‐culture MFCs. Interestingly, pH adjustment is not required for co‐culture MFCs but a base addition is necessary for E. coli MFCs and cultures in vials. Our results show that defined co‐culture MFCs provide clear insights into metabolic interactions among bacteria while maintaining a low operational complexity. Biotechnol. Bioeng. 2014;111: 709–718. © 2013 Wiley Periodicals, Inc.