pH-dependent speciation and hydrogen (H-2) control U(VI) respiration by Desulfovibrio vulgaris
| Title | pH-dependent speciation and hydrogen (H-2) control U(VI) respiration by Desulfovibrio vulgaris |
| Publication Type | Journal Article |
| Year of Publication | 2018 |
| Authors | Kushwaha, S, Marcus, AK, Rittmann, BE |
| Journal | Biotechnology and Bioengineering |
| Volume | 115 |
| Issue | 6 |
| Pagination | 1465-1474 |
| Date Published | JUN |
| Type of Article | Article |
| Abstract | In situ bioreduction of soluble hexavalent uranium U(VI) to insoluble U(IV) (as UO2) has been proposed as a means of preventing U migration in the groundwater. This work focuses on the bioreduction of U(VI) and precipitation of U(IV). It uses anaerobic batch reactors with Desulfovibrio vulgaris, a well-known sulfate, iron, and U(VI) reducer, growing on lactate as the electron donor, in the absence of sulfate, and with a 30-mM bicarbonate buffering. In the absence of sulfate, D. vulgaris reduced >90% of the total soluble U(VI) (1mM) to form U(IV) solids that were characterized by X-ray diffraction and confirmed to be nano-crystalline uraninite with crystallite size 2.8 +/- 0.2nm. pH values between 6 and 10 had minimal impact on bacterial growth and end-product distribution, supporting that the mono-nuclear, and poly-nuclear forms of U(VI) were equally bioavailable as electron acceptors. Electron balances support that H-2 transiently accumulated, but was ultimately oxidized via U(VI) respiration. Thus, D. vulgaris utilized H-2 as the electron carrier to drive respiration of U(VI). Rapid lactate utilization and biomass growth occurred only when U(VI) respiration began to draw down the sink of H-2 and relieve thermodynamic inhibition of fermentation. |
| DOI | 10.1002/bit.26579 |
| Type of Journal (Indian or Foreign) | Foreign |
| Impact Factor (IF) | 4.481 |
Divison category:
Organic Chemistry
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