Reduction of uranium by Desulfovibrio desulfuricans
- Geological Survey, Reston, VA (United States)
The possibility that sulfate-reducing microorganisms contribute to U(VI) reduction in sedimentary environments was investigated. U(VI) was reduced to U(IV) when washed cells of sulfate-grown Desulfovibrio desulfuricans were suspended in a bicarbonate buffer with lactate of H{sub 2} as the electron donor. There was no U(VI) reduction in the absence of an electron donor or when the cells were killed by heat prior to the incubation. The rates of U(VI) reduction were comparable to those in respiratory Fe(III)-reducing microorganisms. Azide or prior exposure of the cells to air did not affect the ability of D. desulfuricans to reduce U(VI). Attempts to grow D. desulfuricans with U(VI) as the electron acceptor were unsuccessful. U(VI) reduction resulted in the extracellular precipitation of the U(IV) mineral uraninite. The presence of sulfate had no effect on the rate of U(VI) reduction. Sulfate and U(VI) were reduced simultaneously. Enzymatic reduction of U(VI) by D. desulfuricans was much faster than nonenzymatic reduction of U(VI) by sulfide, even when cells of D. desulfuricans were added to provide a potential catalytic surface for the nonenzymatic reaction. The results indicate that enzymatic U(VI) reduction by sulfate-reducing microorganisms may be responsible for the accumulation of U(IV) in sulfidogenic environments. Furthermore, since the reduction of U(VI) to U(IV) precipitates uranium from solution, D. desulfuricans might be a useful organism for recovering uranium from contaminated waters and waste streams.
- OSTI ID:
- 5092224
- Journal Information:
- Applied and Environmental Microbiology; (United States), Vol. 58:3; ISSN 0099-2240
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
URANIUM
BIODEGRADATION
DECONTAMINATION
DESULFOVIBRIO
ENZYME ACTIVITY
METABOLISM
REDUCTION
SULFATES
USES
WASTE WATER
ACTINIDES
BACTERIA
CHEMICAL REACTIONS
CLEANING
DECOMPOSITION
ELEMENTS
HYDROGEN COMPOUNDS
LIQUID WASTES
METALS
MICROORGANISMS
OXYGEN COMPOUNDS
SULFATE-REDUCING BACTERIA
SULFUR COMPOUNDS
WASTES
WATER
052001* - Nuclear Fuels- Waste Processing
560300 - Chemicals Metabolism & Toxicology