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Title: Uranium Biomineralization As a Result of Bacterial Phosphatase Activity: Insights From Bacterial Isolates From a Contaminated Subsurface

Abstract

Uranium contamination is an environmental concern at the Department of Energy's Field Research Center in Oak Ridge, Tennessee. In this study, we investigated whether phosphate biomineralization, or the aerobic precipitation of U(VI)-phosphate phases facilitated by the enzymatic activities of microorganisms, offers an alternative to the more extensively studied anaerobic U(VI) bioreduction. Three heterotrophic bacteria isolated from FRC soils were studied for their ability to grow and liberate phosphate in the presence of U(VI) and an organophosphate between pH 4.5 and 7.0. The objectives were to determine whether the strains hydrolyzed sufficient phosphate to precipitate uranium, to determine whether low pH might have an effect on U(VI) precipitation, and to identify the uranium solid phase formed during biomineralization. Two bacterial strains hydrolyzed sufficient organophosphate to precipitate 73-95% total uranium after 120 h of incubation in simulated groundwater. The highest rates of uranium precipitation and phosphatase activity were observed between pH 5.0 and 7.0. EXAFS spectra identified the uranyl phosphate precipitate as an autunite/meta-autunite group mineral. The results of this study indicate that aerobic heterotrophic bacteria within a uranium-contaminated environment that can hydrolyze organophosphate, especially in low pH conditions, may play an important role in the bioremediation of uranium.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
918961
Report Number(s):
SLAC-REPRINT-2007-215
TRN: US0806267
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Environ.Sci.Tech.41:5701-5707,2007
Additional Journal Information:
Journal Volume: 41
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; BACTERIA; BIOREMEDIATION; CONTAMINATION; INCUBATION; MICROORGANISMS; PHOSPHATASES; PHOSPHATES; PRECIPITATION; SOILS; SPECTRA; STRAINS; URANIUM; URANYL PHOSPHATES; Other,OTHER

Citation Formats

Beazley, M J, Martinez, R J, Sobecky, P A, Webb, S M, Taillefert, M, and /Georgia Tech /SLAC, SSRL. Uranium Biomineralization As a Result of Bacterial Phosphatase Activity: Insights From Bacterial Isolates From a Contaminated Subsurface. United States: N. p., 2007. Web. doi:10.1021/es070567g.
Beazley, M J, Martinez, R J, Sobecky, P A, Webb, S M, Taillefert, M, & /Georgia Tech /SLAC, SSRL. Uranium Biomineralization As a Result of Bacterial Phosphatase Activity: Insights From Bacterial Isolates From a Contaminated Subsurface. United States. doi:10.1021/es070567g.
Beazley, M J, Martinez, R J, Sobecky, P A, Webb, S M, Taillefert, M, and /Georgia Tech /SLAC, SSRL. Wed . "Uranium Biomineralization As a Result of Bacterial Phosphatase Activity: Insights From Bacterial Isolates From a Contaminated Subsurface". United States. doi:10.1021/es070567g.
@article{osti_918961,
title = {Uranium Biomineralization As a Result of Bacterial Phosphatase Activity: Insights From Bacterial Isolates From a Contaminated Subsurface},
author = {Beazley, M J and Martinez, R J and Sobecky, P A and Webb, S M and Taillefert, M and /Georgia Tech /SLAC, SSRL},
abstractNote = {Uranium contamination is an environmental concern at the Department of Energy's Field Research Center in Oak Ridge, Tennessee. In this study, we investigated whether phosphate biomineralization, or the aerobic precipitation of U(VI)-phosphate phases facilitated by the enzymatic activities of microorganisms, offers an alternative to the more extensively studied anaerobic U(VI) bioreduction. Three heterotrophic bacteria isolated from FRC soils were studied for their ability to grow and liberate phosphate in the presence of U(VI) and an organophosphate between pH 4.5 and 7.0. The objectives were to determine whether the strains hydrolyzed sufficient phosphate to precipitate uranium, to determine whether low pH might have an effect on U(VI) precipitation, and to identify the uranium solid phase formed during biomineralization. Two bacterial strains hydrolyzed sufficient organophosphate to precipitate 73-95% total uranium after 120 h of incubation in simulated groundwater. The highest rates of uranium precipitation and phosphatase activity were observed between pH 5.0 and 7.0. EXAFS spectra identified the uranyl phosphate precipitate as an autunite/meta-autunite group mineral. The results of this study indicate that aerobic heterotrophic bacteria within a uranium-contaminated environment that can hydrolyze organophosphate, especially in low pH conditions, may play an important role in the bioremediation of uranium.},
doi = {10.1021/es070567g},
journal = {Environ.Sci.Tech.41:5701-5707,2007},
number = ,
volume = 41,
place = {United States},
year = {2007},
month = {10}
}