<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Malvankar, Nikhil S</style></author><author><style face="normal" font="default" size="100%">King, Gary M</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Centimeter-long electron transport in marine sediments via conductive minerals.</style></title><secondary-title><style face="normal" font="default" size="100%">ISME J</style></secondary-title><alt-title><style face="normal" font="default" size="100%">ISME J</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Geologic Sediments</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron</style></keyword><keyword><style  face="normal" font="default" size="100%">Minerals</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Sulfides</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2015 Feb</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">527-31</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Centimeter-long electron conduction through marine sediments, in which electrons derived from sulfide in anoxic sediments are transported to oxygen in surficial sediments, may have an important influence on sediment geochemistry. Filamentous bacteria have been proposed to mediate the electron transport, but the filament conductivity could not be verified and other mechanisms are possible. Surprisingly, previous investigations have never actually measured the sediment conductivity or its basic physical properties. Here we report direct measurements that demonstrate centimeter-long electron flow through marine sediments, with conductivities sufficient to account for previously estimated electron fluxes. Conductivity was lost for oxidized sediments, which contrasts with the previously described increase in the conductivity of microbial biofilms upon oxidation. Adding pyrite to the sediments significantly enhanced the conductivity. These results suggest that the role of conductive minerals, which are more commonly found in sediments than centimeter-long microbial filaments, need to be considered when modeling marine sediment biogeochemistry.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/25050525?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kashefi, K</style></author><author><style face="normal" font="default" size="100%">Moskowitz, B M</style></author><author><style face="normal" font="default" size="100%">Lovley, D R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Characterization of extracellular minerals produced during dissimilatory Fe(III) and U(VI) reduction at 100 degrees C by Pyrobaculum islandicum.</style></title><secondary-title><style face="normal" font="default" size="100%">Geobiology</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Geobiology</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferumoxytol</style></keyword><keyword><style  face="normal" font="default" size="100%">Hot Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Minerals</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Pyrobaculum</style></keyword><keyword><style  face="normal" font="default" size="100%">Uranium</style></keyword><keyword><style  face="normal" font="default" size="100%">X-Ray Diffraction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008 Mar</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">6</style></volume><pages><style face="normal" font="default" size="100%">147-54</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In order to gain insight into the significance of biotic metal reduction and mineral formation in hyperthermophilic environments, metal mineralization as a result of the dissimilatory reduction of poorly crystalline Fe(III) oxide, and U(VI) reduction at 100 degrees C by Pyrobaculum islandicum was investigated. When P. islandicum was grown in a medium with poorly crystalline Fe(III) oxide as an electron acceptor and hydrogen as an electron donor, the Fe(III) oxide was reduced to an extracellular, ultrafine-grained magnetite with characteristics similar to that found in some hot environments and that was previously thought to be of abiotic origin. Furthermore, cell suspensions of P. islandicum rapidly reduced the soluble and oxidized form of uranium, U(VI), to extracellular precipitates of the highly insoluble U(IV) mineral, uraninite (UO(2)). The reduction of U(VI) was dependent on the presence of hydrogen as the electron donor. These findings suggest that microbes may play a key role in metal deposition in hyperthermophilic environments and provide a plausible explanation for such phenomena as magnetite accumulation and formation of uranium deposits at ca. 100 degrees C.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18380877?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Anderson, R T</style></author><author><style face="normal" font="default" size="100%">Chapelle, F H</style></author><author><style face="normal" font="default" size="100%">Lovley, D R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comment on &quot;Abiotic controls on H2 production from basalt-water reactions and implications for aquifer biogeochemistry&quot;.</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Sci Technol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ. Sci. Technol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Hydrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Minerals</style></keyword><keyword><style  face="normal" font="default" size="100%">Organic Chemicals</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Silicates</style></keyword><keyword><style  face="normal" font="default" size="100%">Water</style></keyword><keyword><style  face="normal" font="default" size="100%">Water Microbiology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2001 Apr 1</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">35</style></volume><pages><style face="normal" font="default" size="100%">1556-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">7</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11348102?dopt=Abstract</style></custom1></record></records></xml>