Detection, diversity and expression of aerobic bacterial arsenite oxidase genes

Inskeep, William P.; Macur, Richard E.; Hamamura, Natsuko; Warelow, Thomas P.; Ward, S. A.; Santini, Joanne M.

doi:10.1111/j.1462-2920.2006.01215.x

Cited by 185 publications

(165 citation statements)

References 43 publications

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“…The major groups of As oxidizing bacteria were α-Proteobacteria and β-Proteobacteria in the rhizosphere and were mainly rhizospheric microbes ( Figure S3, Supporting Information), while undefined cluster 1 and cluster 7 was enhanced on roots ( Figure S3, Supporting Information). The diversity of the aroA-like gene revealed in this study is similar to what has been observed in many other diverse environments, such as mining-impacted soils and As-contaminated lake sediments; 18,43,44 whereas in geothermal environments, aroA-like microbes were dominated by Aquificae. 18,45 Arsenic oxidation and reduction (ArsC) share some microbial groups, such as Bradyrhizobiaceae and Rhizobiaceae, and also some different groups ( Figures S1 and S3, Supporting Information).…”

Section: ■ Discussionsupporting

confidence: 86%

“…16,17 On the other hand, some heterotrophic as well as chemoautotrophic microorganisms are able to oxidize As(III) to As(V). 18 Arsenite oxidation is suggested to facilitate As sequestration in metal oxides and is often used as a tool to remediate As-contaminated waters and soils. 19 Arsenic-reducing and arsenic-oxidizing microbes often coexist in the environment, and their relative abundance and activity determine the geochemistry and fate of As in the environment.…”

Section: ■ Introductionmentioning

confidence: 99%

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Arsenic Uptake by Rice Is Influenced by Microbe-Mediated Arsenic Redox Changes in the Rhizosphere

Jia

Huang

Chen

et al. 2014

Environ. Sci. Technol.

189

119

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Arsenic (As) uptake by rice is largely determined by As speciation, which is strongly influenced by microbial activities. However, little is known about interactions between root and rhizosphere microbes, particularly on arsenic oxidation and reduction. In this study, two rice cultivars with different radial oxygen loss (ROL) ability were used to investigate the impact of microbially mediated As redox changes in the rhizosphere on As uptake. Results showed that the cultivar with higher ROL (Yangdao) had lower As uptake than that with lower ROL (Nongken). The enhancement of the rhizospheric effect on the abundance of the arsenite (As(III)) oxidase gene (aroA-like) was greater than on the arsenate (As(V)) reductase gene (arsC), and As(V) respiratory reductase gene (arrA), resulting in As oxidation and sequestration in the rhizosphere, particularly for cultivar Yangdao. The community of As(III)-oxidizing bacteria in the rhizosphere was dominated by α-Proteobacteria and β-Proteobacteria and was influenced by rhizospheric effects, rice straw application, growth stage, and cultivar. Application of rice straw into the soil increased As release and accumulation into rice plants. These results highlighted that uptake of As by rice is influenced by microbial processes, especially As oxidation in the rhizosphere, and these processes are influenced by root ROL and organic matter application. ■ INTRODUCTIONArsenic (As) contamination and its health impacts are widespread around the world. 1,2 Large areas of paddy soils are contaminated by As due to irrigation with As-tainted groundwater, mining, and other industrial activities. Rice is particularly efficient in accumulating As, compared with other cereal crops, as a result of its anaerobic growth conditions. 3 This poses potential harm to people through ingestion of rice, especially in Southeast Asia where rice is consumed as the staple food. 4−6 Rhizospheric chemical processes, such as iron oxidation−reduction and iron plaque formation on root surfaces, play an important role in affecting As uptake by rice plants, and they are largely influenced by oxygen release from rice roots. 7,8 The aerated rice rhizosphere and O 2 -releasing root surface are usually coated with iron (Fe) and manganese (Mn) oxides, while As is precipitated with these oxides mainly as arsenate (As(V)). 8,9 In addition to chemical processes, As speciation and mobility in soils, sediments, and natural water systems are mainly driven by microbial transformations. 10−12 Anaerobic bacteria containing the respiratory reductase (ArrA) can use As(V) as the terminal electron acceptor in respiration and conserve energy from this process. 13 Another pathway for microbial As(V) reduction lies in the widespread As detoxification by As(V) reductase (ArsC). 14,15 Arsenite (As(III)) is more weakly bound to most soil minerals than As(V); thus, As(V) reduction results in As release into soil solutions, especially under anaerobic conditions such as paddy soil. 16,17 On the other hand, some heterotrophic as well a...

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Section: ■ Discussionsupporting

confidence: 86%

Section: ■ Introductionmentioning

confidence: 99%

Arsenic Uptake by Rice Is Influenced by Microbe-Mediated Arsenic Redox Changes in the Rhizosphere

Jia

Huang

Chen

et al. 2014

Environ. Sci. Technol.

189

119

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“…The mixture contained 5 μL 10 × PCR buffer, 4 μL dNTP (1.5 mmol/L, final concentration), 1 μL of each primer (0.4 mmol/L, final concentration), 0.2 μL BSA (10 mg/mL), 2 μL template DNA, 0.4 μL Taq DNA polymerase (5 U/μL, Takara, China) and addition of RNase free ddH 2 O (Takara, China) to a final volume of 50 μL. Universal eubacterial primers (27F:5′-AGAGTTTGATCCTGGCTCAG-3′;1492R:5′-GGYT ACCTTGTTACGACTT-3′) (Lane, 1991) targeting 16S rRNA gene and primers (F:5′-GTSGGBTGYGGMTAYCABGYCTA-3′; R:5′-TTG TASGCBGGNCGRTTRTGRAT-3′) targeting aroA gene (Inskeep et al, 2007) were used for PCR. The occurrence of arsenate reductase gene arsC in the isolated strain was investigated using five reported primers (Bachate et al, 2009;Chang et al, 2008;Macur et al, 2004;Macy et al, 2000;Sun et al, 2004).…”

Section: Pcr Amplification Of 16s Rdna Aroa Gene and Arsc Genementioning

confidence: 99%

“…To date, all known aerobic arsenite oxidases exhibit a heterodimeric structure with molybdopterin (Mo-pterin) and Rieske-like subunits (Inskeep et al, 2007). The large subunit (AroA~90 kDa) of the arsenite oxidase is the first example of a new subgroup of the dimethylsulfoxide (DMSO) reductase family of molybdoenzymes (Ellis et al, 2001).…”

Section: As(iii)-oxidizing Bacteriamentioning

confidence: 99%

Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China

Zhang

Yin

Cai

et al. 2016

Journal of Environmental Sciences

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A mesophilic, Gram-negative, arsenite[As(III)]-oxidizing and arsenate[As(V)]-reducing bacterial strain, Pseudomonas sp. HN-2, was isolated from an As-contaminated soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri. Under aerobic conditions, this strain oxidized 92.0% (61.4 μmol/L) of arsenite to arsenate within 3 hr of incubation. Reduction of As(V) to As(III) occurred in anoxic conditions. Pseudomonas sp. HN-2 is among the first soil bacteria shown to be capable of both aerobic As(III) oxidation and anoxic As(V) reduction. The strain, as an efficient As(III) oxidizer and As(V) reducer in Pseudomonas, has the potential to impact arsenic mobility in both anoxic and aerobic environments, and has potential application in As remediation processes.

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“…As mentioned above, dominant As on iron plaque is As(V), indicating the occurrence of As(III) oxidation in the rhizosphere, but the microbial-mediated As(III) oxidation in soil is largely unknown. Bacterial As(III) oxidase genes are phylogenetically diverse and ecologically widespread [85]. Microbial oxidation of As(III) to As(V) occur under both aerobic and anaerobic soil conditions, which significantly enhance the immobilization of As in the soils, due to the fact that As(V) can more easily co-precipitate with ferric iron or be adsorbed by ferrihydrite [86].…”

Section: Interactions Of Microorganisms With Iron Oxidesmentioning

confidence: 99%

Effects of microbial processes on the fate of arsenic in paddy soil

2012

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Arsenic (As) is a metalloid toxic to organisms including humans. Arsenic in rice represents a significant exposure pathway for the general population, particularly for those subsisting on rice. Arsenic transformation, namely reduction, oxidation and methylation, in soil-rice systems has fundamental impacts on its mobility and toxicity. In addition to soil chemical properties (pH, Eh, metallic oxides, organic matter), microorganisms play critical roles in As transformation and mobility in paddy soil, such as through ArsM (As(III) S-adenosylmethyltransferase) and interactions with iron oxides or organic matters. Arsenic species in paddy soil directly influence As speciation in rice grain because the methylated As species in rice are mainly derived from microbial methylation in paddy soil. This paper aims to provide an overview on the status of the knowledge and gaps on the chemical aspects of As transformation in soil-rice system in conjunction with microbial ecology and functional genes. In addition, potential pathways (manipulation of microorganisms in paddy soil and genetic engineering) to decrease total As and/or inorganic As in rice grain are proposed.

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Detection, diversity and expression of aerobic bacterial arsenite oxidase genes

Cited by 185 publications

References 43 publications

Arsenic Uptake by Rice Is Influenced by Microbe-Mediated Arsenic Redox Changes in the Rhizosphere

Arsenic Uptake by Rice Is Influenced by Microbe-Mediated Arsenic Redox Changes in the Rhizosphere

Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China

Effects of microbial processes on the fate of arsenic in paddy soil

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