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Arsenite [As(III)]-oxidizing bacteria play important roles in reducing arsenic [As] toxicity and mobility in As-contaminated
areas. As-resistant bacteria were isolated from the soils of two abandoned mines in the Republic of Korea. The isolated bacteria
showed relatively high resistances to As(III) up to 26 mM. The PCR-based 16S rRNA analysis revealed that the isolated As-resistant
bacteria were close relatives to Serratia marcescensa, Pseudomonas putida, Pantoea agglomerans, and Alcaligenes sp. Among the five As-resistant bacterial isolates, Alcaligenes sp. strain RS-19 showed the highest As(III)-oxidizing activity in batch tests, completely oxidizing 1 mM of As(III) to As(V)
within 40 h during heterotrophic growth. This study suggests that the indigenous bacteria have evolved to retain the ability
to resist toxic As in the As-contaminated environments and moreover to convert the species to a less toxic form [e.g., from
As(III) to As(V)] and also contribute the biogeochemical cycling of As by being involved in speciation of As. 相似文献
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Lee Seyong Ko Il-Won Yoon In-Ho Kim Dong-Wook Kim Kyoung-Woong 《Environmental geochemistry and health》2019,41(1):469-480
Environmental Geochemistry and Health - Colloid mobilization is a significant process governing colloid-associated transport of heavy metals in subsurface environments. It has been studied for the... 相似文献
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Jin-Soo Chang In-Ho Yoon Ji-Hoon Lee Ki-Rak Kim Jeongyi An Kyoung-Woong Kim 《Environmental geochemistry and health》2010,32(2):95-105
Arsenic is subject to microbial interactions, which support a wide range of biogeochemical transformations of elements in
natural environments such as wetlands. The arsenic detoxification potential of the bacterial strains was investigated with
the arsenite oxidation gene, aox genotype, which were isolated from the natural and constructed wetlands. The isolates were able to grow in the presence of
10 mM of sodium arsenite (As(III) as NaAsO2) and 1 mM of d+glucose. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that these isolated strains resembled members
of the genus that have arsenic-resistant systems (Acinetobacter sp., Aeromonas sp., Agrobacterium sp., Comamonas sp., Enterobacter sp., Pantoea sp., and Pseudomonas sp.) with sequence similarities of 81–98%. One bacterial isolate identified as Pseudomonas stutzeri strain GIST-BDan2 (EF429003) showed the activity of arsenite oxidation and existence of aoxB and aoxR gene, which could play an important role in arsenite oxidation to arsenate. This reaction may be considered as arsenic detoxification
process. The results of a batch test showed that P. stutzeri GIST-BDan2 (EF429003) completely oxidized in 1 mM of As(III) to As(V) within 25–30 h. In this study, microbial activity was
evaluated to provide a better understanding of arsenic biogeochemical cycle in both natural and constructed wetlands, where
ecological niches for microorganisms could be different, with a specific focus on arsenic oxidation/reduction and detoxification. 相似文献
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In-Ho Yoon Deok Hyun Moon Kyoung-Woong Kim Keun-Young Lee Ji-Hoon Lee Min Gyu Kim 《Journal of environmental management》2010,91(11):2322-2328
In this study, the mechanism for the stabilization/solidification (S/S) of arsenic (As)-contaminated soils with Portland cement (PC), and cement kiln dust (CKD) using 1 N HCl extraction fluid, X-ray powder diffraction (XRPD), X-ray absorption near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS) spectroscopy was investigated. The degree of As immobilization after stabilization was assessed using a 1 N HCl extraction on the basis of the Korean Standard Test (KST). After 1 day of curing with 30 wt% PC and 7 days of curing with 50 wt% CKD, the concentration of As leached from the amended soils was less than the Korean countermeasure standard (3 mg L?1). The As concentrations in the leachate treated with PC and CKD were significantly decreased at pH > 3, indicating that pH had a prevailing influence on As mobility. XRPD results indicated that calcium arsenite (Ca–As–O) and sodium calcium arsenate hydrate (NaCaAsO4·7.5H2O) were present in the PC- and CKD-treated slurries as the key phases responsible for As(III) and As(V) immobilization, respectively. The XANES spectroscopy confirmed that the As(III) and As(V) oxidation states of the PC and CKD slurry samples were consistent with the speciated forms in the crystals identified by XRPD. EXAFS spectroscopy showed As–Ca bonding in the As(III)-PC and As(III)-CKD slurries. The main mechanism for the immobilization of As-contaminated soils with PC and CKD was strongly associated with the bonding between As(III) or As(V) and Ca. 相似文献
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