Sulfur-mediated electron shuttling during bacterial iron reduction.

Sulfur-mediated electron shuttling during bacterial iron reduction.

Science (New York, N.Y.) (2014-05-03)

Theodore M Flynn, Edward J O'Loughlin, Bhoopesh Mishra, Thomas J DiChristina, Kenneth M Kemner

ABSTRACT

Microbial reduction of ferric iron [Fe(III)] is an important biogeochemical process in anoxic aquifers. Depending on groundwater pH, dissimilatory metal-reducing bacteria can also respire alternative electron acceptors to survive, including elemental sulfur (S(0)). To understand the interplay of Fe/S cycling under alkaline conditions, we combined thermodynamic geochemical modeling with bioreactor experiments using Shewanella oneidensis MR-1. Under these conditions, S. oneidensis can enzymatically reduce S(0) but not goethite (α-FeOOH). The HS(-) produced subsequently reduces goethite abiotically. Because of the prevalence of alkaline conditions in many aquifers, Fe(III) reduction may thus proceed via S(0)-mediated electron-shuttling pathways.

MATERIALS

Product Number

Brand

Product Description

GF62374765

Iron, foil, 25mm disks, thickness 0.075mm, hard, 99.5%

GF66169020

Iron, foil, not light tested, 50x50mm, thickness 0.001mm, 99.85%

GF35765826

Iron, tube, 100mm, outside diameter 3.18mm, inside diameter 1.96mm, wall thickness 0.61mm, as drawn, 99.5%

GF88665452

Iron, rod, 100mm, diameter 4.8mm, as drawn, 98+%

GF95735571

Iron, tube, 1000mm, outside diameter 8.0mm, inside diameter 5mm, wall thickness 1.5mm, annealed, 99.5%

GF32338717

Iron, foil, 150x150mm, thickness 1.83mm, Quarter hard, 99.5%

GF20981358

Iron, rod, 50mm, diameter 12.7mm, as drawn, 99.95%

GF68187189

Iron, foil, 10mm disks, thickness 0.004mm, 99.99+%

GF12054024

Iron, rod, 500mm, diameter 19mm, as drawn, soft ingot 99.8%

GF17042082

Iron, tube, 200mm, outside diameter 4.0mm, inside diameter 3.6mm, wall thickness 0.2mm, as drawn, 99.5%

GF45478604

Iron, tube, 200mm, outside diameter 6.35mm, inside diameter 5.35mm, wall thickness 0.5mm, as drawn, 99.8%

GF03605802

Iron, foil, 0.5m coil, thickness 0.5mm, coil width 49mm, armco« soft ingot 99.8+%

GF97078281

Iron, tube, 500mm, outside diameter 1.65mm, inside diameter 0.89mm, wall thickness 0.38mm, as drawn, 99.8+%

GF16157190

Iron, foil, 10mm disks, thickness 0.009mm, 99.85%

GF05071081

Iron, foil, 50x50mm, thickness 0.20mm, hard, 99.5%

GF15436469

Iron, foil, 25x25mm, thickness 2mm, as rolled, 99.99+%

GF55566816

Iron, tube, 500mm, outside diameter 1.0mm, inside diameter 0.8mm, wall thickness 0.1mm, as drawn, 99.5%

GF47173260

Iron, rod, 100mm, diameter 8.0mm, as drawn, 99.99+%

GF92236428

Iron, tube, 500mm, outside diameter 12.7mm, inside diameter 9.5mm, wall thickness 1.6mm, annealed, 99.5%

GF94244339

Iron, tube, 500mm, outside diameter 2.38mm, inside diameter 1.6mm, wall thickness 0.39mm, as drawn, 99.8+%

GF83094824

Iron, rod, 300mm, diameter 6.0mm, as drawn, 99.99+%

GF45684232

Iron, rod, 25mm, diameter 10.0mm, as drawn, 99.99+%

GF38919279

Iron, tube, 200mm, outside diameter 20.0mm, inside diameter 16mm, wall thickness 2.0mm, annealed, 99.5%

GF85519299

Iron, foil, 300x300mm, thickness 1.0mm, as rolled, 99.5%

GF82007029

Iron, rod, 100mm, diameter 30mm, as drawn, armcO« soft ingot 99.8%

GF24256649

Iron, foil, 10mm disks, thickness 0.007mm, 99.85%

GF59202176

Iron, foil, 10m coil, thickness 0.038mm, hard, 99.5%

GF69332519

Iron, foil, 50x50mm, thickness 0.25mm, as rolled, 99.99+%

GF23825493

Iron, rod, 200mm, diameter 50mm, as drawn, armcO« soft ingot 99.8%

GF34939345

Iron, tube, 200mm, outside diameter 12.0mm, inside diameter 9mm, wall thickness 1.5mm, annealed, 99.5%