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Title: Impact of different environmental conditions on the aggregation of biogenic U(IV) nanoparticles synthesized by Desulfovibrio alaskensis G20

This study investigates the impact of specific environmental conditions on the formation of colloidal U(IV) nanoparticles by the sulfate reducing bacteria (SRB, Desulfovibrio alaskensis G20). The reduction of soluble U(VI) to less soluble U(IV) was quantitatively investigated under growth and non-growth conditions in bicarbonate or 1,4-piperazinediethanesulfonic acid (PIPES) buffered environments. Here, the results showed that under non-growth conditions, the majority of the reduced U nanoparticles aggregated and precipitated out of solution. High resolution transmission electron microscopy revealed that only a very small fraction of cells had reduced U precipitates in the periplasmic spaces in the presence of PIPES buffer, whereas in the presence of bicarbonate buffer, reduced U was also observed in the cytoplasm with greater aggregation of biogenic U(IV) particles at higher initial U(VI) concentrations. The same experiments were repeated under growth conditions using two different electron donors (lactate and pyruvate) and three electron acceptors (sulfate, fumarate, and thiosulfate). In contrast to the results of the non-growth experiments, even after 0.2 μm filtration, the majority of biogenic U(IV) remained in the aqueous phase resulting in potentially mobile biogenic U(IV) nanoparticles. Size fractionation results showed that U(IV) aggregates were between 18 and 200 nm in diameter, and thus could be very mobile.more » The findings of this study are helpful to assess the size and potential mobility of reduced U nanoparticles under different environmental conditions, and would provide insights on their potential impact affecting U(VI) bioremediation efforts at subsurface contaminated sites.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [2]
  1. Southern Methodist Univ., Dallas, TX (United States). Dept. of Civil and Environmental Engineering
  2. South Dakota School of Mines and Technology, Rapid City, SD (United States). Dept. of Chemical and Biological Engineering
  3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). WR Wiley Environmental Molecular Sciences Lab.
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  5. Washington State Univ., Pullman, WA (United States). Dept. of Civil and Environmental Engineering
  6. Montana State Univ., Bozeman, MT (United States). Dept. of Chemical and Biological Engineering
Publication Date:
Grant/Contract Number:
AC02-05CH11231; FG02-07ER64366
Type:
Accepted Manuscript
Journal Name:
Biometals
Additional Journal Information:
Journal Volume: 29; Journal Issue: 6; Journal ID: ISSN 0966-0844
Publisher:
Springer Netherlands
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; Biogenic uranium; Mobile uraninite; Nanoparticles; Sulfate reducing bacteria; Uranium aggregates
OSTI Identifier:
1474981

Şengör, S. Sevinç, Singh, Gursharan, Dohnalkova, Alice, Spycher, Nicolas, Ginn, Timothy R., Peyton, Brent M., and Sani, Rajesh K.. Impact of different environmental conditions on the aggregation of biogenic U(IV) nanoparticles synthesized by Desulfovibrio alaskensis G20. United States: N. p., Web. doi:10.1007/s10534-016-9969-6.
Şengör, S. Sevinç, Singh, Gursharan, Dohnalkova, Alice, Spycher, Nicolas, Ginn, Timothy R., Peyton, Brent M., & Sani, Rajesh K.. Impact of different environmental conditions on the aggregation of biogenic U(IV) nanoparticles synthesized by Desulfovibrio alaskensis G20. United States. doi:10.1007/s10534-016-9969-6.
Şengör, S. Sevinç, Singh, Gursharan, Dohnalkova, Alice, Spycher, Nicolas, Ginn, Timothy R., Peyton, Brent M., and Sani, Rajesh K.. 2016. "Impact of different environmental conditions on the aggregation of biogenic U(IV) nanoparticles synthesized by Desulfovibrio alaskensis G20". United States. doi:10.1007/s10534-016-9969-6. https://www.osti.gov/servlets/purl/1474981.
@article{osti_1474981,
title = {Impact of different environmental conditions on the aggregation of biogenic U(IV) nanoparticles synthesized by Desulfovibrio alaskensis G20},
author = {Şengör, S. Sevinç and Singh, Gursharan and Dohnalkova, Alice and Spycher, Nicolas and Ginn, Timothy R. and Peyton, Brent M. and Sani, Rajesh K.},
abstractNote = {This study investigates the impact of specific environmental conditions on the formation of colloidal U(IV) nanoparticles by the sulfate reducing bacteria (SRB, Desulfovibrio alaskensis G20). The reduction of soluble U(VI) to less soluble U(IV) was quantitatively investigated under growth and non-growth conditions in bicarbonate or 1,4-piperazinediethanesulfonic acid (PIPES) buffered environments. Here, the results showed that under non-growth conditions, the majority of the reduced U nanoparticles aggregated and precipitated out of solution. High resolution transmission electron microscopy revealed that only a very small fraction of cells had reduced U precipitates in the periplasmic spaces in the presence of PIPES buffer, whereas in the presence of bicarbonate buffer, reduced U was also observed in the cytoplasm with greater aggregation of biogenic U(IV) particles at higher initial U(VI) concentrations. The same experiments were repeated under growth conditions using two different electron donors (lactate and pyruvate) and three electron acceptors (sulfate, fumarate, and thiosulfate). In contrast to the results of the non-growth experiments, even after 0.2 μm filtration, the majority of biogenic U(IV) remained in the aqueous phase resulting in potentially mobile biogenic U(IV) nanoparticles. Size fractionation results showed that U(IV) aggregates were between 18 and 200 nm in diameter, and thus could be very mobile. The findings of this study are helpful to assess the size and potential mobility of reduced U nanoparticles under different environmental conditions, and would provide insights on their potential impact affecting U(VI) bioremediation efforts at subsurface contaminated sites.},
doi = {10.1007/s10534-016-9969-6},
journal = {Biometals},
number = 6,
volume = 29,
place = {United States},
year = {2016},
month = {9}
}