@article {3128,
	title = {Magnetite compensates for the lack of a pilin-associated c-type cytochrome in extracellular electron exchange.},
	journal = {Environ Microbiol},
	volume = {17},
	year = {2015},
	month = {2015 Mar},
	pages = {648-55},
	abstract = {<p>Nanoscale magnetite can facilitate microbial extracellular electron transfer that plays an important role in biogeochemical cycles, bioremediation and several bioenergy strategies, but the mechanisms for the stimulation of extracellular electron transfer are poorly understood. Further investigation revealed that magnetite attached to the electrically conductive pili of Geobacter species in a manner reminiscent of the association of the multi-heme c-type cytochrome OmcS with the pili of Geobacter sulfurreducens. Magnetite conferred extracellular electron capabilities on an OmcS-deficient strain unable to participate in interspecies electron transfer or Fe(III) oxide reduction. In the presence of magnetite wild-type cells repressed expression of the OmcS gene, suggesting that cells might need to produce less OmcS when magnetite was available. The finding that magnetite can compensate for the lack of the electron transfer functions of a multi-heme c-type cytochrome has implications not only for the function of modern microbes, but also for the early evolution of microbial electron transport mechanisms.</p>},
	keywords = {Cytochrome c Group, Electron Transport, Electrons, Ferrosoferric Oxide, Fimbriae Proteins, Fimbriae, Bacterial, Gene Expression Regulation, Bacterial, Geobacter, Heme, Oxides},
	issn = {1462-2920},
	doi = {10.1111/1462-2920.12485},
	author = {Liu, Fanghua and Rotaru, Amelia-Elena and Shrestha, Pravin M and Malvankar, Nikhil S and Nevin, Kelly P and Lovley, Derek R}
}
@article {3134,
	title = {Syntrophic growth with direct interspecies electron transfer as the primary mechanism for energy exchange.},
	journal = {Environ Microbiol Rep},
	volume = {5},
	year = {2013},
	month = {2013 Dec},
	pages = {904-10},
	abstract = {<p>Direct interspecies electron transfer (DIET) through biological electrical connections is an alternative to interspecies H2 transfer as a mechanism for electron exchange in syntrophic cultures. However, it has not previously been determined whether electrons received via DIET yield energy to support cell growth. In order to investigate this, co-cultures of Geobacter metallireducens, which can transfer electrons to wild-type G. sulfurreducens via DIET, were established with a citrate synthase-deficient G. sulfurreducens strain that can receive electrons for respiration through DIET only. In a medium with ethanol as the electron donor and fumarate as the electron acceptor, co-cultures with the citrate synthase-deficient G. sulfurreducens strain metabolized ethanol as fast as co-cultures with wild-type, but the acetate that G. metallireducens generated from ethanol oxidation accumulated. The lack of acetate metabolism resulted in less fumarate reduction and lower cell abundance of G. sulfurreducens. RNAseq analysis of transcript abundance was consistent with a lack of acetate metabolism in G. sulfurreducens and revealed gene expression levels for the uptake hydrogenase, formate dehydrogenase, the pilus-associated c-type cytochrome OmcS and pili consistent with electron transfer via DIET. These results suggest that electrons transferred via DIET can serve as the sole energy source to support anaerobic respiration.</p>},
	keywords = {Acetates, Anaerobiosis, Citrate (si)-Synthase, Cytochrome c Group, Electron Transport, Electrons, Energy Metabolism, Ethanol, Fimbriae, Bacterial, Formate Dehydrogenases, Fumarates, Geobacter, Oxidation-Reduction},
	issn = {1758-2229},
	doi = {10.1111/1758-2229.12093},
	author = {Shrestha, Pravin Malla and Rotaru, Amelia-Elena and Aklujkar, Muktak and Liu, Fanghua and Shrestha, Minita and Summers, Zarath M and Malvankar, Nikhil and Flores, Dan Carlo and Lovley, Derek R}
}
