Dawn E. Holmes Trevor L. Woodard Erich S. Hinlein David W. Ostendorf Derek R. Lovely Kelly P. Nevin 2005 <p><span>Fe(III)-reducing isolates were recovered from two aquifers in which Fe(III) reduction is known to be important. Strain Bem</span><span class="jp-sup">T</span><span> was enriched from subsurface sediments collected in Bemidji, MN, USA, near a site where Fe(III) reduction is important in aromatic hydrocarbon degradation. Strains P11, P35</span><span class="jp-sup">T</span><span> and P39 were isolated from the groundwater of an aquifer in Plymouth, MA, USA, in which Fe(III) reduction is important because of long-term inputs of acetate as a highway de-icing agent to the subsurface. All four isolates were Gram-negative, slightly curved rods that grew best in freshwater media. Strains P11, P35</span><span class="jp-sup">T</span><span> and P39 exhibited motility via means of monotrichous flagella. Analysis of the 16S rRNA and </span><span class="jp-italic">nifD</span><span> genes indicated that all four strains are </span><span class="jp-italic">δ</span><span>-proteobacteria and members of the </span><span class="jp-italic">Geobacter</span><span> cluster of the </span><span class="jp-italic">Geobacteraceae</span><span>. Differences in phenotypic and phylogenetic characteristics indicated that the four isolates represent two novel species within the genus </span><span class="jp-italic">Geobacter</span><span>. All of the isolates coupled the oxidation of acetate to the reduction of Fe(III) [iron(III) citrate, amorphous iron(III) oxide, iron(III) pyrophosphate and iron(III) nitrilotriacetate]. All four strains utilized ethanol, lactate, malate, pyruvate and succinate as electron donors and malate and fumarate as electron acceptors. Strain Bem</span><span class="jp-sup">T</span><span> grew fastest at 30 °C, whereas strains P11, P35</span><span class="jp-sup">T</span><span> and P39 grew equally well at 17, 22 and 30 °C. In addition, strains P11, P35</span><span class="jp-sup">T</span><span> and P39 were capable of growth at 4 °C. The names </span><span class="jp-italic">Geobacter bemidjiensis</span><span> sp. nov. (type strain Bem</span><span class="jp-sup">T</span><span>=ATCC BAA-1014</span><span class="jp-sup">T</span><span>=DSM 16622</span><span class="jp-sup">T</span><span>=JCM 12645</span><span class="jp-sup">T</span><span>) and </span><span class="jp-italic">Geobacter psychrophilus</span><span> sp. nov. (strains P11, P35</span><span class="jp-sup">T</span><span> and P39; type strain P35</span><span class="jp-sup">T</span><span>=ATCC BAA-1013</span><span class="jp-sup">T</span><span>=DSM 16674</span><span class="jp-sup">T</span><span>=JCM 12644</span><span class="jp-sup">T</span><span>) are proposed.</span></p> application/pdf 10.1099/ijs.0.63417-0 en Microbiology Society Geobacter bemidjiensis sp. nov. and Geobacter psychrophilus sp. nov., two novel Fe(III)-reducing subsurface isolates article