Electron‐transfer coupling in microbial fuel cells: 1. comparison of redox‐mediator reduction rates and respiratory rates of bacteria

Roller, Sibel; Bennetto, H. P.; Delaney, G. M.; Mason, Jeremy R.; Stirling, J. L.; Thurston, Christopher F.

doi:10.1002/jctb.280340103

Cited by 187 publications

(55 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The role of e-proteobacteria, as well as FCBs, in power production remains unconstrained. Geobacter and other d-proteobacteria are known exoelectrogens (Lovley, 2006), and g-proteobacteria, including E. coli, have been shown to be capable of extracellular electron transfer via exogenous electron shuttles (Roller et al, 1984;McKinlay and Zeikus, 2004). As such, these g-proteobacteria may be physiologically capable of exploiting the anode as an electron acceptor, and the data shown here provide evidence for this notion because there is increasing power production in the 0.3 V MFC whereas g-proteobacterial cell densities increase and Geobacter cell densities decrease (though notably the majority of power produced in the 0.3 V MFC occurs after the g-proteobacterial cell density is diminished; Figure 4a).…”

Section: Discussionmentioning

confidence: 99%

Quantitative population dynamics of microbial communities in plankton-fed microbial fuel cells

et al. 2009

View full text Add to dashboard Cite

This study examines changes in diversity and abundance of bacteria recovered from the anodes of microbial fuel cells (MFCs) in relation to anode potential, power production and geochemistry. MFCs were batch-fed with plankton, and two systems were maintained at different potentials whereas one was at open circuit for 56.8 days. Bacterial phylogenetic diversity during peak power was assessed from 16S rDNA clone libraries. Throughout the experiment, microbial community structure was examined using terminal restriction fragment length polymorphism. Changes in cell density of key phylotypes, including representatives of d-, e-, c-proteobacteria and Flavobacterium-CytophagaBacteroides, were enumerated by quantitative PCR. Marked differences in phylogenetic diversity were observed during peak power versus the final time point, and changes in microbial community structure were strongly correlated to dissolved organic carbon and ammonium concentrations within the anode chambers. Community structure was notably different between the MFCs at different anode potentials during the onset of peak power. At the final time point, however, the anode-hosted communities in all MFCs were similar. These data demonstrate that differences in growth, succession and population dynamics of key phylotypes were due to anode potential, which may relate to their ability to exploit the anode as an electron acceptor. The geochemical milieu, however, governs overall community diversity and structure. These differences reflect the physiological capacity of specific phylotypes to catabolize plankton-derived organic matter and exploit the anode of an MFC for their metabolism directly or indirectly through syntrophy.

show abstract

Section: Discussionmentioning

confidence: 99%

Quantitative population dynamics of microbial communities in plankton-fed microbial fuel cells

et al. 2009

View full text Add to dashboard Cite

show abstract

“…An increase of the potential beyond the normal biological boundaries indicates inability of the bacteria to provide electrons at a sufficient rate to avoid electrochemical oxidation of solutes. Electrode surface increase and catalysis (Park and Zeikus, 2003) or mediator addition (Roller et al, 1984) would be the necessary modifications to improve this situation. The reverse process can also be envisaged at a cathode.…”

Section: Bes and Microbial Ecology In The Natural Environmentmentioning

confidence: 99%

Microbial ecology meets electrochemistry: electricity-driven and driving communities

et al. 2007

View full text Add to dashboard Cite

Bio-electrochemical systems (BESs) have recently emerged as an exciting technology. In a BES, bacteria interact with electrodes using electrons, which are either removed or supplied through an electrical circuit. The most-described type of BES is microbial fuel cells (MFCs), in which useful power is generated from electron donors as, for example, present in wastewater. This form of charge transport, known as extracellular electron transfer, was previously extensively described with respect to metals such as iron and manganese. The importance of these interactions in global biogeochemical cycles is essentially undisputed. A wide variety of bacteria can participate in extracellular electron transfer, and this phenomenon is far more widespread than previously thought. The use of BESs in diverse research projects is helping elucidate the mechanism by which bacteria shuttle electrons externally. New forms of interactions between bacteria have been discovered demonstrating how multiple populations within microbial communities can co-operate to achieve energy generation. New environmental processes that were difficult to observe or study previously can now be simulated and improved via BESs. Whereas pure culture studies make up the majority of the studies performed thus far, even greater contributions of BESs are expected to occur in natural environments and with mixed microbial communities. Owing to their versatility, unmatched level of control and capacity to sustain novel processes, BESs might well serve as the foundation of a new environmental biotechnology. While highlighting some of the major breakthroughs and addressing only recently obtained data, this review points out that despite rapid progress, many questions remain unanswered.

show abstract

“…These conditions arise in the presence of poised-potential electrodes or insoluble minerals, such as iron oxides (3)(4)(5), and in multicellular communities (biofilms) where the formation of chemical gradients leads to oxidant limitation for cells at depth (6)(7)(8)(9). Diverse microbes secrete redoxactive compounds with the capacity to function as electron shuttles (10)(11)(12). In the pathogenic bacterium Pseudomonas aeruginosa PA14, electron-shuttling antibiotics called phenazines support survival on poised-potential electrodes and balance the intracellular redox state of cells in anoxic biofilm subzones (1,9).…”

mentioning

confidence: 99%

Electron-shuttling antibiotics structure bacterial communities by modulating cellular levels of c-di-GMP

Okegbe

Fields

Cole

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

101

View full text Add to dashboard Cite

Diverse organisms secrete redox-active antibiotics, which can be used as extracellular electron shuttles by resistant microbes. Shuttlemediated metabolism can support survival when substrates are available not locally but rather at a distance. Such conditions arise in multicellular communities, where the formation of chemical gradients leads to resource limitation for cells at depth. In the pathogenic bacterium Pseudomonas aeruginosa PA14, antibiotics called phenazines act as oxidants to balance the intracellular redox state of cells in anoxic biofilm subzones. PA14 colony biofilms show a profound morphogenic response to phenazines resulting from electron acceptor-dependent inhibition of ECM production. This effect is reminiscent of the developmental responses of some eukaryotic systems to redox control, but for bacterial systems its mechanistic basis has not been well defined. Here, we identify the regulatory protein RmcA and show that it links redox conditions to PA14 colony morphogenesis by modulating levels of bis-(3′,5′)-cyclic-dimeric-guanosine (c-di-GMP), a second messenger that stimulates matrix production, in response to phenazine availability. RmcA contains four Per-Arnt-Sim (PAS) domains and domains with the potential to catalyze the synthesis and degradation of c-di-GMP. Our results suggest that phenazine production modulates RmcA activity such that the protein degrades c-di-GMP and thereby inhibits matrix production during oxidizing conditions. RmcA thus forms a mechanistic link between cellular redox sensing and community morphogenesis analogous to the functions performed by PAS-domain-containing regulatory proteins found in complex eukaryotes.W hen microbial cells cannot import or are physically separated from metabolic electron donors or acceptors, diffusible compounds can act as electron carriers and support survival on these substrates (1, 2). These conditions arise in the presence of poised-potential electrodes or insoluble minerals, such as iron oxides (3-5), and in multicellular communities (biofilms) where the formation of chemical gradients leads to oxidant limitation for cells at depth (6-9). Diverse microbes secrete redoxactive compounds with the capacity to function as electron shuttles (10-12). In the pathogenic bacterium Pseudomonas aeruginosa PA14, electron-shuttling antibiotics called phenazines support survival on poised-potential electrodes and balance the intracellular redox state of cells in anoxic biofilm subzones (1, 9).Similar to those formed by many species of microbes, colonies of PA14 develop intricate wrinkle structures on agar-solidified growth media (13). Phenazines profoundly alter PA14 colony morphogenesis, inhibiting the onset of wrinkle formation and changing the organization of wrinkles (12) (Fig. 1A). Modeling of resource availability within colonies suggests that the earlier increase in the colony surface area-to-volume ratio in phenazine-null (Δphz) mutants maximizes access to oxygen for cells that would otherwise become limited for oxidant (14). Measurements of...

show abstract

Electron‐transfer coupling in microbial fuel cells: 1. comparison of redox‐mediator reduction rates and respiratory rates of bacteria

Cited by 187 publications

References 13 publications

Quantitative population dynamics of microbial communities in plankton-fed microbial fuel cells

Quantitative population dynamics of microbial communities in plankton-fed microbial fuel cells

Microbial ecology meets electrochemistry: electricity-driven and driving communities

Electron-shuttling antibiotics structure bacterial communities by modulating cellular levels of c-di-GMP

Contact Info

Product

Resources

About