A defined co‐culture of Geobacter sulfurreducens and Escherichia coli in a membrane‐less microbial fuel cell. Issue 4 (22nd November 2013)

• Record Type: Journal Article
• Authors: Bourdakos, Nicholas; Marsili, Enrico; Mahadevan, Radhakrishnan
• Is Part Of: Biotechnology and bioengineering. Volume 111:Issue 4(2014:Apr.)
• Page Start: 709
• Page End: 718
• Publication Date: 2013-11-22
• Subjects: Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.25137
• Languages: English
• ISSNs: 0006-3592

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>ABSTRACT</title> <sec id="bit25137-sec-0001" sec-type="section"> <p>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 <italic>Geobacter sulfurreducens</italic> and <italic>Escherichia coli</italic> co‐culture and compare them with pure culture MFCs. <italic>G. sulfurreducens</italic> MFCs are sparged to maintain anaerobic conditions, while co‐culture MFCs rely on <italic>E. coli</italic> for oxygen removal. <italic>G. sulfurreducens</italic> MFCs have a power output of 128 mW m<sup>−2</sup>, compared to 63 mW m<sup>−2</sup> from the co‐culture MFCs. Analysis of metabolites shows that succinate production in co‐culture MFCs decreases current production by <italic>G. sulfurreducens</italic> 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 <italic>E. coli</italic> 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.</p> </sec> </abstract>