Comparison of anode bacterial communities and performance in microbial fuel cells with different electron donors

Abstract

Microbial fuel cells (MFCs) harness the electrochemical activity of certain microbes for the production of electricity from reduced compounds. Characterizations of MFC anode biofilms have collectively shown very diverse microbial communities, raising ecological questions about competition and community succession within these anode-reducing communities. Three sets of triplicate, two-chamber MFCs inoculated with anaerobic sludge and differing in energy sources (acetate, lactate, and glucose) were operated to explore these questions. Based on 16S rDNA-targeted denaturing gradient gel electrophoresis (DGGE), all anode communities contained sequences closely affiliated with Geobacter sulfurreducens (>99% similarity) and an uncultured bacterium clone in the Bacteroidetes class (99% similarity). Various other Geobacter-like sequences were also enriched in most of the anode biofilms. While the anode communities in replicate reactors for each substrate generally converged to a reproducible community, there were some variations in the relative distribution of these putative anode-reducing Geobacter-like strains. Firmicutes were found only in glucose-fed MFCs, presumably serving the roles of converting complex carbon into simple molecules and scavenging oxygen. The maximum current density in these systems was negatively correlated with internal resistance variations among replicate reactors and, likely, was only minimally affected by anode community differences in these two-chamber MFCs with high internal resistance.

Effects of electron donors and acceptors in generating bioelectrical energy using microbial fuel cells

“…Relatively higher CE of 63±5.4% was obtained using air-cathode. The voltage and the CE obtained in this study with acetate were comparable to the previous MFCs studies (Jung and Regan, 2007;Oh and Logan, 2006;Oh et al, 2004). Fig.…”

Electrode-Based Approach for Monitoring In Situ Microbial Activity During Subsurface Bioremediation

“…Additionally, colonization of subsurface electrodes at the Rifle site by Geobacter species was similar to the abundance of Geobacter species found on the anodes of sediment microbial fuel cells [13,16,24], as well as the colonization of anodes by Geobacter species in laboratory systems capable of producing high current densities when inoculated with sewage and amended with acetate [39][40][41]. However, a wide diversity of microorganisms are capable of electron transfer to electrodes via a variety of mechanisms [36], and it remains quite possible that in other subsurface environments microorganisms other than Geobacter species could be the primary current producers.…”

Engineering materials and biology to boost performance of microbial fuel cells: a critical review

“…39 This scenario may be regarded as a tight collaboration amongst the interdependent and competing bacterial species contributing to the consortium aimed at the full fuel substrate degradation. The pictorial representation in Fig.…”