@article {3107,
	title = {Protozoan grazing reduces the current output of microbial fuel cells.},
	journal = {Bioresour Technol},
	volume = {193},
	year = {2015},
	month = {2015 Oct},
	pages = {8-14},
	abstract = {<p>Several experiments were conducted to determine whether protozoan grazing can reduce current output from sediment microbial fuel cells. When marine sediments were amended with eukaryotic inhibitors, the power output from the fuel cells increased 2-5-fold. Quantitative PCR showed that Geobacteraceae sequences were 120 times more abundant on anodes from treated fuel cells compared to untreated fuel cells, and that Spirotrichea sequences in untreated fuel cells were 200 times more abundant on anode surfaces than in the surrounding sediments. Defined studies with current-producing biofilms of Geobacter sulfurreducens and pure cultures of protozoa demonstrated that protozoa that were effective in consuming G. sulfurreducens reduced current production up to 91\% when added to G. sulfurreducens fuel cells. These results suggest that anode biofilms are an attractive food source for protozoa and that protozoan grazing can be an important factor limiting the current output of sediment microbial fuel cells.</p>},
	keywords = {Bioelectric Energy Sources, Biofilms, Electricity, Electrodes, Eukaryota, Geobacter, Geologic Sediments},
	issn = {1873-2976},
	doi = {10.1016/j.biortech.2015.06.056},
	author = {Holmes, Dawn E and Nevin, Kelly P and Snoeyenbos-West, Oona L and Woodard, Trevor L and Strickland, Justin N and Lovley, Derek R}
}
@article {3126,
	title = {Going wireless: Fe(III) oxide reduction without pili by Geobacter sulfurreducens strain JS-1.},
	journal = {Appl Environ Microbiol},
	volume = {80},
	year = {2014},
	month = {2014 Jul},
	pages = {4331-40},
	abstract = {<p>Previous studies have suggested that the conductive pili of Geobacter sulfurreducens are essential for extracellular electron transfer to Fe(III) oxides and for optimal long-range electron transport through current-producing biofilms. The KN400 strain of G. sulfurreducens reduces poorly crystalline Fe(III) oxide more rapidly than the more extensively studied DL-1 strain. Deletion of the gene encoding PilA, the structural pilin protein, in strain KN400 inhibited Fe(III) oxide reduction. However, low rates of Fe(III) reduction were detected after extended incubation (>30 days) in the presence of Fe(III) oxide. After seven consecutive transfers, the PilA-deficient strain adapted to reduce Fe(III) oxide as fast as the wild type. Microarray, whole-genome resequencing, proteomic, and gene deletion studies indicated that this adaptation was associated with the production of larger amounts of the c-type cytochrome PgcA, which was released into the culture medium. It is proposed that the extracellular cytochrome acts as an electron shuttle, promoting electron transfer from the outer cell surface to Fe(III) oxides. The adapted PilA-deficient strain competed well with the wild-type strain when both were grown together on Fe(III) oxide. However, when 50\% of the culture medium was replaced with fresh medium every 3 days, the wild-type strain outcompeted the adapted strain. A possible explanation for this is that the necessity to produce additional PgcA, to replace the PgcA being continually removed, put the adapted strain at a competitive disadvantage, similar to the apparent selection against electron shuttle-producing Fe(III) reducers in many anaerobic soils and sediments. Despite increased extracellular cytochrome production, the adapted PilA-deficient strain produced low levels of current, consistent with the concept that long-range electron transport through G. sulfurreducens biofilms is more effective via pili.</p>},
	keywords = {Adaptation, Physiological, Biofilms, DNA, Bacterial, Electron Transport, Ferric Compounds, Fimbriae Proteins, Fimbriae, Bacterial, Gene Deletion, Geobacter, Oligonucleotide Array Sequence Analysis, Proteomics, Sequence Analysis, DNA},
	issn = {1098-5336},
	doi = {10.1128/AEM.01122-14},
	author = {Smith, Jessica A and Tremblay, Pier-Luc and Shrestha, Pravin Malla and Snoeyenbos-West, Oona L and Franks, Ashley E and Nevin, Kelly P and Lovley, Derek R}
}
