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Growth with high planktonic biomass in Shewanella oneidensis fuel cells

Eastern Cereal and Oilseed Research Center, Agriculture and Agri-Food Canada, Ottawa, ON, Canada.
FEMS Microbiology Letters (Impact Factor: 2.72). 02/2008; 278(1):29-35. DOI: 10.1111/j.1574-6968.2007.00964.x
Source: PubMed

ABSTRACT Shewanella oneidensis MR-1 grew for over 50 days in microbial fuel cells, incompletely oxidizing lactate to acetate with high recovery of the electrons derived from this reaction as electricity. Electricity was produced with lactate or hydrogen and current was comparable to that of electricigens which completely oxidize organic substrates. However, unlike fuel cells with previously described electricigens, in which cells are primarily attached to the anode, at least as many of the S. oneidensis cells were planktonic as were attached to the anode. These results demonstrate that S. oneidensis may conserve energy for growth with an electrode serving as an electron acceptor and suggest that multiple strategies for electron transfer to fuel cell anodes exist.

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    • "Electron consumption in MFCs with no additional electron acceptors is related to two reactions, i.e. current generation (consumed by cathodic reaction) and bacterial metabolisms (Lanthier et al., 2008). The later reaction usually accounts for a major part for Shewanella species as the CE of Shewanella MFCs were generally lower than 50% (Ringeisen et al., 2006; Lanthier et al., 2008). However, the suppressed cell growth in fumarate-MFCs compared to control MFCs would leave more electrons for current generation. "
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    ABSTRACT: To understand the interactions between bacterial electrode respiration and the other ambient bacterial electron acceptor reductions, alternative electron acceptors (nitrate, Fe2O3, fumarate, azo dye MB17) were added singly or multiply into Shewanella decolorationis microbial fuel cells (MFCs). All the added electron acceptors were reduced simultaneously with current generation. Adding nitrate or MB17 resulted in more rapid cell growth, higher flavin concentration and higher biofilm metabolic viability, but lower columbic efficiency (CE) and normalized energy recovery (NER) while the CE and NER were enhanced by Fe2O3 or fumarate. The added electron acceptors also significantly influenced the cyclic voltammetry profile of anode biofilm probably via altering the cytochrome c expression. The highest power density was observed in MFCs added with MB17 due to the electron shuttle role of the naphthols from MB17 reduction. The results provided important information for MFCs applied in practical environments where contains various electron acceptors.
    Bioresource Technology 05/2014; 164C:270-275. DOI:10.1016/j.biortech.2014.04.098 · 5.04 Impact Factor
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    • "Electron consumption in MFCs with no additional electron acceptors is related to two reactions, i.e. current generation (consumed by cathodic reaction) and bacterial metabolisms (Lanthier et al., 2008). The later reaction usually accounts for a major part for Shewanella species as the CE of Shewanella MFCs were generally lower than 50% (Ringeisen et al., 2006; Lanthier et al., 2008). However, the suppressed cell growth in fumarate-MFCs compared to control MFCs would leave more electrons for current generation. "
    [Show abstract] [Hide abstract]
    ABSTRACT: To understand the interactions between bacterial electrode respiration and the other ambient bacterial electron acceptor reductions, alternative electron acceptors (nitrate, Fe2O3, fumarate, azo dye MB17) were added singly or multiply into Shewanella decolorationis microbial fuel cells (MFCs). All the added electron acceptors were reduced simultaneously with current generation. Adding nitrate or MB17 resulted in more rapid cell growth, higher flavin concentration and higher biofilm metabolic viability, but lower columbic efficiency (CE) and normalized energy recovery (NER) while the CE and NER were enhanced by Fe2O3 or fumarate. The added electron acceptors also significantly influenced the cyclic voltammetry profile of anode biofilm probably via altering the cytochrome c expression. The highest power density was observed in MFCs added with MB17 due to the electron shuttle role of the naphthols from MB17 reduction. The results provided important information for MFCs applied in practical environments where contains various electron acceptors.
    Bioresource Technology 01/2014; 164:270–275. · 5.04 Impact Factor
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    • "Like Geobacteraceae, members of the family Shewanellaceae may conserve energy for growth during dissimilatory iron reduction and may also produce conductive pili structures (Gorby et al., 2006). However, Shewanellaceae may grow aerobically and exhibit a distinctly alternate mechanism from Geobacteraceae for externalizing electrons to electrode surfaces which involves planktonic cells as well as attached biofilm cells (Lanthier et al., 2008). Marsili et al. (2008) identified flavin compounds produced by S. oneidensis which mediate electron transfer to electrodes and may enable planktonic cells of S. oneidensis to respiration when not in contact with the biofilm or electrode. "
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    ABSTRACT: The efficiency of microbial fuel cells (MFCs) is affected by several factors such as activation overpotentials, ohmic losses and concentration polarization. These factors are handled in micro-sized MFCs using special electrodes with physically or chemically modified surfaces constructed with specified materials. Most of the existing μLscale MFCs show great potential in rapid screening of electrochemically-active microbes and electrode performance; although they generate significantly lower volumetric power density compared with their mL counterparts because of their high internal resistance. This review presents the development of microfluidic MFCs, with summarization of their advantages and challenges, and focuses on the efforts done to minimize the adverse effects of internal resistance (ohmic and non-ohmic) on their performance.
    Bioresource Technology 05/2013; 142:672-682. DOI:10.1016/j.biortech.2013.05.061 · 5.04 Impact Factor
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