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Title: Fe(III) Reduction and U(VI) Immobilization by Paenibacillus sp. Strain 300A, Isolated from Hanford 300A Subsurface Sediments

Abstract

A facultative iron-reducing (Fe(III)-reducing) Paenibacillus sp. strain was isolated from Hanford 300A subsurface sediment biofilms that was capable of reducing soluble Fe(III) complexes (Fe(III)-NTA and Fe(III)-citrate) but unable to reduce poorly crystalline ferrihydrite (Fh). However, Paenibacillus sp. 300A was capable of reducing Fh in the presence of low concentrations (2 µM) of either of electron transfer mediators (ETMs) flavin mononucleotide (FMN) or anthraquinone-2,6-disulfonate (AQDS). Maximum initial Fh reduction rates were observed at catalytic concentrations (<10 µM) of either FMN or AQDS. Higher FMN concentrations inhibited Fh reduction, while increased AQDS concentrations did not. We found that Paenibacillus sp. 300A also could reduce Fh in the presence of natural ETMs from Hanford 300A subsurface sediments. In the absence of ETMs, Paenibacillus sp. 300A was capable of immobilizing U(VI) through both reduction and adsorption. The relative contributions of adsorption and microbial reduction to U(VI) removal from the aqueous phase were ~7:3 in PIPES and ~1:4 in bicarbonate buffer. Our study demonstrated that Paenibacillus sp. 300A catalyzes Fe(III) reduction and U(VI) immobilization and that these reactions benefit from externally added or naturally existing ETMs in 300A subsurface sediments.

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1059185
Report Number(s):
PNNL-SA-90509
34942; KP1704020
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Applied and Environmental Microbiology, 78(22):8001-8009
Additional Journal Information:
Journal Name: Applied and Environmental Microbiology, 78(22):8001-8009
Country of Publication:
United States
Language:
English
Subject:
Paenibacillus; Hanford sediments, U(VI) immobilization; Environmental Molecular Sciences Laboratory

Citation Formats

Ahmed, B., Cao, B., McLean, Jeffrey S., Ica, Tuba, Dohnalkova, Alice, Istanbullu, Ozlem, Paksoy, Akin, Fredrickson, Jim K., and Beyenal, Haluk. Fe(III) Reduction and U(VI) Immobilization by Paenibacillus sp. Strain 300A, Isolated from Hanford 300A Subsurface Sediments. United States: N. p., 2012. Web. doi:10.1128/AEM.01844-12.
Ahmed, B., Cao, B., McLean, Jeffrey S., Ica, Tuba, Dohnalkova, Alice, Istanbullu, Ozlem, Paksoy, Akin, Fredrickson, Jim K., & Beyenal, Haluk. Fe(III) Reduction and U(VI) Immobilization by Paenibacillus sp. Strain 300A, Isolated from Hanford 300A Subsurface Sediments. United States. doi:10.1128/AEM.01844-12.
Ahmed, B., Cao, B., McLean, Jeffrey S., Ica, Tuba, Dohnalkova, Alice, Istanbullu, Ozlem, Paksoy, Akin, Fredrickson, Jim K., and Beyenal, Haluk. Wed . "Fe(III) Reduction and U(VI) Immobilization by Paenibacillus sp. Strain 300A, Isolated from Hanford 300A Subsurface Sediments". United States. doi:10.1128/AEM.01844-12.
@article{osti_1059185,
title = {Fe(III) Reduction and U(VI) Immobilization by Paenibacillus sp. Strain 300A, Isolated from Hanford 300A Subsurface Sediments},
author = {Ahmed, B. and Cao, B. and McLean, Jeffrey S. and Ica, Tuba and Dohnalkova, Alice and Istanbullu, Ozlem and Paksoy, Akin and Fredrickson, Jim K. and Beyenal, Haluk},
abstractNote = {A facultative iron-reducing (Fe(III)-reducing) Paenibacillus sp. strain was isolated from Hanford 300A subsurface sediment biofilms that was capable of reducing soluble Fe(III) complexes (Fe(III)-NTA and Fe(III)-citrate) but unable to reduce poorly crystalline ferrihydrite (Fh). However, Paenibacillus sp. 300A was capable of reducing Fh in the presence of low concentrations (2 µM) of either of electron transfer mediators (ETMs) flavin mononucleotide (FMN) or anthraquinone-2,6-disulfonate (AQDS). Maximum initial Fh reduction rates were observed at catalytic concentrations (<10 µM) of either FMN or AQDS. Higher FMN concentrations inhibited Fh reduction, while increased AQDS concentrations did not. We found that Paenibacillus sp. 300A also could reduce Fh in the presence of natural ETMs from Hanford 300A subsurface sediments. In the absence of ETMs, Paenibacillus sp. 300A was capable of immobilizing U(VI) through both reduction and adsorption. The relative contributions of adsorption and microbial reduction to U(VI) removal from the aqueous phase were ~7:3 in PIPES and ~1:4 in bicarbonate buffer. Our study demonstrated that Paenibacillus sp. 300A catalyzes Fe(III) reduction and U(VI) immobilization and that these reactions benefit from externally added or naturally existing ETMs in 300A subsurface sediments.},
doi = {10.1128/AEM.01844-12},
journal = {Applied and Environmental Microbiology, 78(22):8001-8009},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {11}
}