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

GF34105643

Iron, rod, 50mm, diameter 6.0mm, as drawn, 99.99+%

GF34053780

Iron, foil, 10mm disks, thickness 0.0125mm, 99.99+%

GF03382624

Iron, foil, 100x100mm, thickness 0.5mm, as rolled, 99.99+%

GF02011509

Iron, tube, 1000mm, outside diameter 6.35mm, inside diameter 5.35mm, wall thickness 0.5mm, as drawn, 99.8%

GF46709264

Iron, foil, 50x50mm, thickness 1.83mm, Quarter hard, 99.5%

GF21695722

Iron, wire reel, 2m, diameter 0.13mm, hard, 99.99+%

GF73600512

Iron, tube, 1000mm, outside diameter 12.7mm, inside diameter 9.5mm, wall thickness 1.6mm, annealed, 99.5%

GF31513418

Iron, tube, 100mm, outside diameter 1.65mm, inside diameter 0.89mm, wall thickness 0.38mm, as drawn, 99.8+%

GF13791708

Iron, rod, 50mm, diameter 8.0mm, as drawn, 99.99+%

GF00018560

Iron, foil, 10mm disks, thickness 0.015mm, 99.85%

GF35224871

Iron, rod, 500mm, diameter 3.2mm, as drawn, 98+%

GF32008979

Iron, tube, 500mm, outside diameter 10.0mm, inside diameter 7mm, wall thickness 1.5mm, annealed, 99.5%

GF96220065

Iron, foil, 25x25mm, thickness 3.1mm, as rolled, 99.95%

GF29377154

Iron, tube, 100mm, outside diameter 2.0mm, inside diameter 1.08mm, wall thickness 0.46mm, as drawn, 99.5%

GF91427003

Iron, rod, 200mm, diameter 40mm, as drawn, armcO« soft ingot 99.8%

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Iron, rod, 500mm, diameter 4.8mm, as drawn, 98+%

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Iron, tube, 200mm, outside diameter 2.0mm, inside diameter 1.08mm, wall thickness 0.46mm, as drawn, 99.5%

GF38499250

Iron, tube, 1000mm, outside diameter 4.0mm, inside diameter 3.6mm, wall thickness 0.2mm, as drawn, 99.5%

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Iron, foil, 25x25mm, thickness 1.0mm, as rolled, 99.99+%

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Iron, foil, 100x100mm, thickness 0.5mm, hard, 99.5%

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Iron, foil, 100x100mm, thickness 0.38mm, hard, 99.5%

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Iron, tube, 500mm, outside diameter 20.0mm, inside diameter 16mm, wall thickness 2.0mm, annealed, 99.5%

GF13137410

Iron, rod, 500mm, diameter 12.7mm, as drawn, 98+%

GF06171151

Iron, foil, 50x50mm, thickness 2.0mm, as rolled, 99.95%

GF58434060

Iron, foil, 10mm disks, thickness 0.006mm, 99.85%

GF38658707

Iron, foil, 100x100mm, thickness 1.83mm, Quarter hard, 99.5%

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Iron, rod, 500mm, diameter 2.0mm, as drawn, 99.99+%

GF87060371

Iron, rod, 200mm, diameter 30mm, as drawn, armcO« soft ingot 99.8%

GF39176624

Iron, tube, 200mm, outside diameter 1.65mm, inside diameter 0.89mm, wall thickness 0.38mm, as drawn, 99.8+%