@article {3079,
	title = {The Archaellum of Methanospirillum hungatei Is Electrically Conductive.},
	journal = {mBio},
	volume = {10},
	year = {2019},
	month = {2019 Apr 16},
	abstract = {<p>Microbially produced electrically conductive protein filaments are of interest because they can function as conduits for long-range biological electron transfer. They also show promise as sustainably produced electronic materials. Until now, microbially produced conductive protein filaments have been reported only for bacteria. We report here that the archaellum of  is electrically conductive. This is the first demonstration that electrically conductive protein filaments have evolved in  Furthermore, the structure of the  archaellum was previously determined (N. Poweleit, P. Ge, H. N. Nguyen, R. R. O. Loo, et al., Nat Microbiol 2:16222, 2016, https://doi.org/10.1038/nmicrobiol.2016.222). Thus, the archaellum of  is the first microbially produced electrically conductive protein filament for which a structure is known. We analyzed the previously published structure and identified a core of tightly packed phenylalanines that is one likely route for electron conductance. The availability of the  archaellum structure is expected to substantially advance mechanistic evaluation of long-range electron transport in microbially produced electrically conductive filaments and to aid in the design of "green" electronic materials that can be microbially produced with renewable feedstocks. Microbially produced electrically conductive protein filaments are a revolutionary, sustainably produced, electronic material with broad potential applications. The design of new protein nanowires based on the known  archaellum structure could be a major advance over the current empirical design of synthetic protein nanowires from electrically conductive bacterial pili. An understanding of the diversity of outer-surface protein structures capable of electron transfer is important for developing models for microbial electrical communication with other cells and minerals in natural anaerobic environments. Extracellular electron exchange is also essential in engineered environments such as bioelectrochemical devices and anaerobic digesters converting wastes to methane. The finding that the archaellum of  is electrically conductive suggests that some archaea might be able to make long-range electrical connections with their external environment.</p>},
	keywords = {Electric Conductivity, Electricity, Electron Transport, Flagella, Methanospirillum, Phenylalanine},
	issn = {2150-7511},
	doi = {10.1128/mBio.00579-19},
	author = {Walker, David J F and Martz, Eric and Holmes, Dawn E and Zhou, Zimu and Nonnenmann, Stephen S and Lovley, Derek R}
}
@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 {588,
	title = {Electrode-reducing microorganisms that harvest energy from marine sediments.},
	journal = {Science},
	volume = {295},
	year = {2002},
	month = {2002 Jan 18},
	pages = {483-5},
	abstract = {Energy in the form of electricity can be harvested from marine sediments by placing a graphite electrode (the anode) in the anoxic zone and connecting it to a graphite cathode in the overlying aerobic water. We report a specific enrichment of microorganisms of the family Geobacteraceae on energy-harvesting anodes, and we show that these microorganisms can conserve energy to support their growth by oxidizing organic compounds with an electrode serving as the sole electron acceptor. This finding not only provides a method for extracting energy from organic matter, but also suggests a strategy for promoting the bioremediation of organic contaminants in subsurface environments.},
	keywords = {Aerobiosis, Anaerobiosis, Anthraquinones, Benzoates, Biodegradation, Environmental, Carbon Dioxide, Colony Count, Microbial, Deltaproteobacteria, DNA, Ribosomal, Electricity, Electrodes, Electrons, Energy Metabolism, Geologic Sediments, Oxidation-Reduction, RNA, Ribosomal, 16S, Seawater, Sodium Acetate},
	issn = {1095-9203},
	doi = {10.1126/science.1066771},
	author = {Bond, Daniel R and Holmes, Dawn E and Tender, Leonard M and Lovley, Derek R}
}
@article {580,
	title = {Harnessing microbially generated power on the seafloor.},
	journal = {Nat Biotechnol},
	volume = {20},
	year = {2002},
	month = {2002 Aug},
	pages = {821-5},
	abstract = {In many marine environments, a voltage gradient exists across the water sediment interface resulting from sedimentary microbial activity. Here we show that a fuel cell consisting of an anode embedded in marine sediment and a cathode in overlying seawater can use this voltage gradient to generate electrical power in situ. Fuel cells of this design generated sustained power in a boat basin carved into a salt marsh near Tuckerton, New Jersey, and in the Yaquina Bay Estuary near Newport, Oregon. Retrieval and analysis of the Tuckerton fuel cell indicates that power generation results from at least two anode reactions: oxidation of sediment sulfide (a by-product of microbial oxidation of sedimentary organic carbon) and oxidation of sedimentary organic carbon catalyzed by microorganisms colonizing the anode. These results demonstrate in real marine environments a new form of power generation that uses an immense, renewable energy reservoir (sedimentary organic carbon) and has near-immediate application.},
	keywords = {Bacteria, Bioelectric Energy Sources, Biotechnology, Carbon, Conservation of Energy Resources, DNA, Ribosomal, Electricity, Electrodes, Environmental Microbiology, Geologic Sediments, Molecular Sequence Data, New Jersey, Oceans and Seas, Oregon, Oxidation-Reduction, RNA, Bacterial, RNA, Ribosomal, 16S, Sulfides},
	issn = {1087-0156},
	doi = {10.1038/nbt716},
	author = {Tender, Leonard M and Reimers, Clare E and Stecher, Hilmar A and Holmes, Dawn E and Bond, Daniel R and Lowy, Daniel A and Pilobello, Kanoelani and Fertig, Stephanie J and Lovley, Derek R}
}
