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Hendry MJ, Kirk L, Warner J, Shaw S, Peyton BM, Schmeling E, Barbour SL. Selenate bioreduction in a large in situ field trial. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 933:172869. [PMID: 38697548 DOI: 10.1016/j.scitotenv.2024.172869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/06/2024] [Accepted: 04/27/2024] [Indexed: 05/05/2024]
Abstract
Removing selenium (Se) from mine effluent is a common challenge. A long-term, in situ experiment was conducted to bioremediate large volumes (up to 7500 mc d-1) of Se(VI)-contaminated water (mean 87 μg L-1) by injecting the water into a saturated waste rock fill (SRF) at a coal mining operation in Elk Valley, British Columbia, Canada. To stimulate/maintain biofilm growth in the SRF, labile organic carbon (methanol) and nutrients were added to the water prior to its injection. A conservative tracer (Br-) was also added to track the migration of injected water across the SRF, identify wells with minimal dilution and used to quantify the extent of bioreduction. The evolution of the Se species through the SRF was monitored in time and space for 201 d. Selenium concentrations of <3.8 μg L-1 were attained in monitoring wells located 38 m from the injection wells after 114 to 141 d of operation. Concentrations of Se species in water samples from complementary long-term (351-498 d) column experiments using influent Se(VI) concentrations of 1.0 mg L-1 were consistent with the results of the in situ experiment. Solid samples collected at the completion of the column experiments confirmed the presence of indigenous Se-reducing bacteria and that the sequestered Se was present as insoluble Se(0), likely in Se-S ring compounds. Based on the success of this ongoing bioremediation experiment, this technology is being applied at other mine sites.
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Affiliation(s)
- M Jim Hendry
- Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2, Canada.
| | - Lisa Kirk
- Enviromin, Inc., 524 Professional Drive, Bozeman, MT 59715, USA.
| | - Jeff Warner
- Canadian Light Source Inc., University of Saskatchewan, 101 Perimeter Road, Saskatoon, SK S7N 0X4, Canada.
| | - Shannon Shaw
- SRK Consulting, 1066 W. Hastings St., Vancouver, BC V6E 3X2, Canada.
| | - Brent M Peyton
- Department of Chemical and Biological Engineering, Center for Biofilm Engineering, 305 Cobleigh Hall, Montana State University, Bozeman, MT, USA.
| | - Erin Schmeling
- Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2, Canada.
| | - S Lee Barbour
- Department of Civil and Geological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada
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2
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Palace V, Graves S, Brandt J. Guidance on assessing the potential impacts of selenium in freshwater ecosystems. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2024. [PMID: 38888255 DOI: 10.1002/ieam.4969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 05/10/2024] [Accepted: 05/21/2024] [Indexed: 06/20/2024]
Abstract
Despite decades of fate and effects studies, environmental selenium (Se) contamination and management remain an issue for many freshwater systems in North America. Several regulatory bodies have promulgated updated targets or management levels for Se; however, additional guidance on best practices for monitoring Se to protect freshwater aquatic life is warranted. In this article, we describe current approaches to assessing the ecological risks of Se in impaired freshwater systems and outline recommended methods for collecting and analyzing biological and abiotic samples and interpreting data. Because reproductive impairment of fish populations is most commonly used to determine the potential impacts of Se, several biological factors that could affect Se toxicity are explored, including diet, trophic positions, reproductive biology, body size and maturity, migratory movements, and use of seasonal habitats. Measuring Se concentrations in mature eggs is the most reliable metric for estimating potential reproductive impairment in fish populations because the range of toxicity thresholds is relatively narrow for all but a few tolerant fish species. In situations where collecting mature eggs is not feasible, we review the use of alternative fish tissue for estimating potential effects. Factors affecting Se uptake from freshwater are also considered with guidance on collecting abiotic (e.g., water and sediment) and biotic components of aquatic food webs (e.g., macroinvertebrates, biofilm). Integr Environ Assess Manag 2024;00:1-16. © 2024 SETAC.
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Affiliation(s)
- Vince Palace
- International Institute for Sustainable Development-Experimental Lakes Area, Winnipeg, Manitoba, Canada
| | | | - Jessica Brandt
- Department of Natural Resources and the Environment & Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, Connecticut, USA
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3
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Klaczek CE, Goss GG, Glover CN. Mechanistic characterization of waterborne selenite uptake in the water flea, Daphnia magna, indicates water chemistry affects toxicity in coal mine-impacted waters. CONSERVATION PHYSIOLOGY 2024; 12:coad108. [PMID: 38293640 PMCID: PMC10823350 DOI: 10.1093/conphys/coad108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 11/20/2023] [Accepted: 12/15/2023] [Indexed: 02/01/2024]
Abstract
Concentrations of selenium that exceed regulatory guidelines have been associated with coal mining activities and have been linked to detrimental effects on aquatic ecosystems and the organisms therein. Although the major route of selenium uptake in macroinvertebrates is via the diet, the uptake of waterborne selenite (HSeO3-), the prominent form at circumneutral pH, can be an important contributor to selenium body burden and thus selenium toxicity. In the current study, radiolabelled selenite (Se75) was used to characterize the mechanism of selenite uptake in the water flea, Daphnia magna. The concentration dependence (1-32 μM) of selenite uptake was determined in 1-hour uptake assays in artificial waters that independently varied in bicarbonate, chloride, sulphate, phosphate and selenate concentrations. At concentrations representative of those found in highly contaminated waters, selenite uptake was phosphate-dependent and inhibited by foscarnet, a phosphate transport inhibitor. At higher concentrations, selenite uptake was dependent on waterborne bicarbonate concentration and inhibited by the bicarbonate transporter inhibitor DIDS (4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid). These findings suggest that concentrations of phosphate in coal mining-affected waters could alter selenite uptake in aquatic organisms and could ultimately affect the toxic impacts of selenium in such waters.
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Affiliation(s)
- Chantelle E Klaczek
- Department of Biological Sciences, CW 405 Biological Sciences Bldg., University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Greg G Goss
- Department of Biological Sciences, CW 405 Biological Sciences Bldg., University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Chris N Glover
- Department of Biological Sciences, CW 405 Biological Sciences Bldg., University of Alberta, Edmonton, Alberta T6G 2E9, Canada
- Faculty of Science and Technology and Athabasca River Basin Research Institute, Athabasca University, 1 University Dr., Athabasca, Alberta T9S 3A3, Canada
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4
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Pałka I, Saniewska D, Bielecka L, Kobos J, Grzybowski W. Uptake and trophic transfer of selenium into phytoplankton and zooplankton of the southern Baltic Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 909:168312. [PMID: 37926260 DOI: 10.1016/j.scitotenv.2023.168312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/07/2023]
Abstract
Selenium (Se) is an essential trace element and displays a narrow range of concentration between essentiality and toxicity. Se plays an important role in ameliorating mercury toxicity in organisms. Despite this there are only a few reports concerning Se concentration in plankton, the first link in the trophic chain that determines the uptake and transfer of Se to subsequent trophic levels. This paper aimed to determine Se concentration in water, phytoplankton, and zooplankton in the Baltic Sea, and factors affecting Se absorption from the environment and its transfer to higher trophic levels. Sea water and plankton samples were collected from the Gulf of Gdańsk during 5 cruises (4 seasons: 2019-2022) at 4 research stations. An additional cruise was undertaken in July 2020 in the open waters of the southern Baltic Sea. The median Se concentrations in the Gulf of Gdańsk was 0.25 μg·dm-3. While the median of Se concentration in phytoplankton was 1.11 μg·g-1 and in zooplankton was 1.25 μg·g-1. The biomass of organisms in the phytoplankton and zooplankton in the Gulf of Gdańsk showed an important role in shaping Se concentration. Seasonal trends in Se concentration in zooplankton could be the result of taxa composition changes, changes to dietary intake of Se, changes in growth dilution, or potentially some combination of factors. The highest biomagnification rate occurred in the summer. In contrast, in autumn and winter, when plankton biomass was dominated by the ciliate species Mesodinium rubrum, the highest Se concentration in plankton was measured. Further scientific studies are needed into the active biocomponents of the Se concentration process, including Se speciation, to more fully understand the dynamics of Se concentrations in the pelagic food webs of this and other freshwater and marine systems.
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Affiliation(s)
- Izabela Pałka
- Institute of Oceanology, Polish Academy of Sciences, Marine Chemistry and Biochemistry Department, Powstańców Warszawy 55, 81-712 Sopot, Poland
| | - Dominika Saniewska
- University of Gdańsk, Faculty of Oceanography and Geography, Division of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
| | - Luiza Bielecka
- University of Gdańsk, Faculty of Oceanography and Geography, Division of Marine Ecosystems Functioning, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Justyna Kobos
- University of Gdańsk, Faculty of Oceanography and Geography, Division of Marine Biotechnology, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Waldemar Grzybowski
- University of Gdańsk, Faculty of Oceanography and Geography, Division of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
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5
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Martin AJ, Kuang C, Wallschläger D. Expansion of the Conceptual Model for the Accumulation of Selenium in Lentic Food Chains to Include Redox-Controlled Generation and Diffusion of Selenite and Dissolved Organo-Selenium Compounds. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2022; 41:2859-2869. [PMID: 35975431 DOI: 10.1002/etc.5465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 07/21/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
The controls governing the availability of reduced selenium (Se) species, namely selenite (Se[IV]) and dissolved organo-Se (DOSe), to primary producers at the sediment-water interface in depositional environments (i.e., lentic systems) were assessed through consideration of theoretical principles and field data. Selenite is generated in suboxic sediment porewater via the microbially mediated reduction of selenate (Se[IV]) and/or reductive dissolution of Se-bearing iron oxides. Field data for lentic environments demonstrate that the production of DOSe in sediment porewaters can also be redox- and depth-dependent. In this manner, the remobilization depths of Se(IV) and DOSe in depositional environments are dependent on the vertical redox gradient (dEh/dz), where deeper depths of remobilization are observed in less reducing sedimentary environments (lower dEh/dz). In turn, remobilization depth has a direct bearing on the concentration of dissolved Se(IV) and DOSe that may be realized at the sediment-water interface because the depth of reaction governs the diffusive path length, concentration gradient, and rate of diffusional transport toward the sediment-water interface. The principles that link sediment redox gradients, depth of remobilization, diffusive transport processes, and concentration of reduced Se species at the sediment-water interface have a direct bearing on the potential for Se uptake by primary producers in lentic food chains (e.g., phytoplankton, biofilms, bacteria). Overall, these processes complement the current conceptual "benthic detrital food chain" model that describes the accumulation of Se in lentic systems. Environ Toxicol Chem 2022;41:2859-2869. © 2022 SETAC.
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Affiliation(s)
- Alan J Martin
- Lorax Environmental Services, Vancouver, British Columbia, Canada
| | - Cheng Kuang
- Lorax Environmental Services, Vancouver, British Columbia, Canada
| | - Dirk Wallschläger
- Department of Chemistry and Biochemistry, Wilfrid Laurier University, Waterloo, Ontario, Canada
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6
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Tran TAT, Dinh QT, Zhou F, Zhai H, Xue M, Du Z, Bañuelos GS, Liang D. Mechanisms underlying mercury detoxification in soil-plant systems after selenium application: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:46852-46876. [PMID: 34254235 DOI: 10.1007/s11356-021-15048-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/17/2021] [Indexed: 05/12/2023]
Abstract
Feasible countermeasures to mitigate mercury (Hg) accumulation and its deleterious effects on crops are urgently needed worldwide. Selenium (Se) fertilizer application is a cost-effective strategy to reduce Hg concentrations, promote agro-environmental sustainability and food safety, and decrease the public health risk posed by Hg-contaminated soils and its accumulation in food crops. This holistic review focuses on the processes and detoxification mechanisms of Hg in whole soil-plant systems after Se application. The reduction of Hg bioavailability in soil, the formation of inert HgSe or/and HgSe-containing proteinaceous complexes in the rhizosphere and/or roots, and the reduction of plant root uptake and translocation of Hg in plant after Se application are systemically discussed. In addition, the positive responses in plant physiological and biochemical processes to Se application under Hg stress are presented to show the possible mechanisms for protecting the plant. However, application of high levels Se showed synergistic toxic effect with Hg and inhibited plant growth. The effectiveness of Se application methods, rates, and species on Hg detoxification is compared. This review provides a good approach for plant production in Hg-contaminated areas to meet food security demands and reduce the public health risk.
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Affiliation(s)
- Thi Anh Thu Tran
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Faculty of Natural Resources and Environmental Management, Thu Dau Mot University, Thu Dau Mot City, Binh Duong, Vietnam
| | - Quang Toan Dinh
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Department of Natural Resources and Environment of Thanh Hoa, Thanh Hoa, 400570, Vietnam
| | - Fei Zhou
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Hui Zhai
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Mingyue Xue
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zekun Du
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Gary S Bañuelos
- USDA, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA, 93648-9757, USA
| | - Dongli Liang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi, China.
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling, 712100, Shaanxi, China.
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7
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Etteieb S, Magdouli S, Komtchou SP, Zolfaghari M, Tanabene R, Brar KK, Calugaru LL, Brar SK. Selenium speciation and bioavailability from mine discharge to the environment: a field study in Northern Quebec, Canada. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:50799-50812. [PMID: 33970419 DOI: 10.1007/s11356-021-14335-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
The speciation, behaviour, and bioavailability of released selenium (Se) from mine effluent discharge to sediments and plants were assessed. Discharged mine effluent containing 65±0.9 μg/L of total Se subsequently contaminated the exposed sediment with an average total Se concentration of 321 mg/kg as well as exposed Typha latifolia plants where 534 and 92 mg/kg were found in roots and leaves, respectively. The strategy of T. latifolia in Se phytoremediation consisted of a phytostabilization and accumulation of Se predominantly in roots. Se plant root uptake was promoted by synergistic effects of Cu, Pb, Zn, and Cd while Co, Fe, Mn, Ni, Na, K, and Mg had antagonistic effects. Se plant uptake was also governed by sediment characteristics mainly pH, total Se, and iron concentration. Se speciation results demonstrated that the most accumulated Se species by T. latifolia roots were selenite and selenomethionine with average concentrations of 2.68 and 2.04 mg/kg respectively while other Se species were the most translocated (average translocation factor of 1.89). Se speciation in roots was positively correlated with sediment pH, organic matter, electrical conductivity, and iron concentration. This study confirms deploying corrective measures for mine effluent treatment before discharge in a sediment-plant environment to protect living organisms from toxic effects. T. latifolia is recommended as a Se-hyperaccumulator to be used for mine soil phytoremediation in cold regions in Canada.
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Affiliation(s)
- Selma Etteieb
- Centre technologique des résidus industriels en Abitibi Témiscamingue, 433 boulevard du collège, Rouyn-Noranda, J9X 0E1, Canada
- Centre Eau, Terre et Environnement, Institut national de la recherche scientifique, Université du Québec, 490 rue de la Couronne, Québec, G1K 9A9, Canada
| | - Sara Magdouli
- Centre technologique des résidus industriels en Abitibi Témiscamingue, 433 boulevard du collège, Rouyn-Noranda, J9X 0E1, Canada.
- Centre Eau, Terre et Environnement, Institut national de la recherche scientifique, Université du Québec, 490 rue de la Couronne, Québec, G1K 9A9, Canada.
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, M3J 1P3, Canada.
| | - Simon Pierre Komtchou
- Centre technologique des résidus industriels en Abitibi Témiscamingue, 433 boulevard du collège, Rouyn-Noranda, J9X 0E1, Canada
| | - Mehdi Zolfaghari
- Centre technologique des résidus industriels en Abitibi Témiscamingue, 433 boulevard du collège, Rouyn-Noranda, J9X 0E1, Canada
| | - Rayen Tanabene
- Centre technologique des résidus industriels en Abitibi Témiscamingue, 433 boulevard du collège, Rouyn-Noranda, J9X 0E1, Canada
| | - Kamalpreet Kaur Brar
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, M3J 1P3, Canada
| | - Luliana Laura Calugaru
- Centre technologique des résidus industriels en Abitibi Témiscamingue, 433 boulevard du collège, Rouyn-Noranda, J9X 0E1, Canada
| | - Satinder Kaur Brar
- Centre Eau, Terre et Environnement, Institut national de la recherche scientifique, Université du Québec, 490 rue de la Couronne, Québec, G1K 9A9, Canada
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, M3J 1P3, Canada
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Farell J, Wallschläger D. Gas chromatography-mass spectrometric characterization of Se nS m compounds in synthetic melts and sediments. Talanta 2019; 205:120159. [PMID: 31450391 DOI: 10.1016/j.talanta.2019.120159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 10/26/2022]
Abstract
A gas chromatography-mass spectrometry (GC-MS) method was used to characterize and identify mixed selenium-sulfur compounds with the formula SenSm in synthetic selenium-sulfur melts and selenium-impacted sediments. This method shows strong fragmentation of SenSm compounds in the electron ionization source, which makes conclusive identification of discrete compounds difficult. Despite these limitations, three SenSm compounds (SeS4, SeS5, and SeS6) were identified conclusively in synthetic samples, and several others were shown to be mixed SeS compounds, without being able to determine a molecular formula. Three selenium-impacted sediments from sites containing similar total selenium concentrations (11.0-18.5 ppm) were extracted with carbon disulfide (CS2); each of the three sediments contained at least 12 SenSm compounds, ten of which were common to all three sediments. Two of the compounds identified in the synthetic samples were also found in all three sediments, SeS4 and SeS5, and a third, SeS6 was found in one sediment sample. This is the first time that cyclic SenSm compounds have been confirmed to exist in the environment.
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Affiliation(s)
- Jana Farell
- Water Quality Center, Trent University, Canada.
| | - Dirk Wallschläger
- Water Quality Center, Trent University, Canada; Environmental and Resource Science Program, and Department of Chemistry, Trent University, 1600 West Bank Drive, Peterborough, Ontario, K9J 7B8, Canada
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Genome-resolved metagenomics links microbial dynamics to failure and recovery of a bioreactor removing nitrate and selenate from mine-influenced water. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.107297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Markwart B, Liber K, Xie Y, Raes K, Hecker M, Janz D, Doig LE. Selenium oxyanion bioconcentration in natural freshwater periphyton. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 180:693-704. [PMID: 31146156 DOI: 10.1016/j.ecoenv.2019.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 04/22/2019] [Accepted: 05/01/2019] [Indexed: 06/09/2023]
Abstract
Selenium (Se) enrichment has been demonstrated to vary by several orders of magnitude among species of planktonic algae. This is a substantial source of uncertainty when modelling Se biodynamics in aquatic systems. In addition, Se bioconcentration data are largely lacking for periphytic species of algae, and for multi-species periphyton biofilms, adding to the challenge of modelling Se transfer in periphyton-based food webs. To better predict Se dynamics in periphyton dominated, freshwater ecosystems, the goal of this study was to assess the relative influence of periphyton community composition on the uptake of waterborne Se oxyanions. Naturally grown freshwater periphyton communities, sampled from five different water bodies, were exposed to environmentally relevant concentrations of selenite [Se(IV)] or selenate [Se(VI)] (nominal concentrations of 5 and 25 μg Se L-1) under similar, controlled laboratory conditions for a period of 8 days. Unique periphyton assemblages were derived from the five different field sites, as confirmed by light microscopy and targeted DNA sequencing of the plastid 23S rRNA gene in algae. Selenium accumulation demonstrated a maximum of 23.6-fold difference for Se(IV) enrichment and 2.1-fold difference for Se(VI) enrichment across the periphyton/biofilm assemblages tested. The assemblage from one field site demonstrated both high accumulation of Se(IV) and iron, and was subjected to additional experimentation to elucidate the mechanism(s) of Se accumulation. Selenite accumulation (at nominal concentrations of 5 and 25 μg Se L-1 and mean pH of 7.5 across all treatment replicates) was assessed in both unaltered and heat-killed periphyton, and in periphyton from the same site grown without light to exclude phototrophic organisms. Following an exposure length of 8 days, all periphyton treatments showed similar levels of Se accumulation, indicating that much of the apparent uptake of Se(IV) was due to non-biological processes (i.e., surface adsorption). The results of this study will help reduce uncertainty in the prediction of Se dynamics and food-chain transfer in freshwater environments. Further exploration of the ecological consequences of extracellular adsorption of Se(IV) to periphyton, rather than intracellular absorption, is recommended to further refine predictions related to Se biodynamics in freshwater food webs.
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Affiliation(s)
- Blue Markwart
- Toxicology Center, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Karsten Liber
- Toxicology Center, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, 117 Science Place, Saskatoon, SK, S7N 5C8, Canada.
| | - Yuwei Xie
- Toxicology Center, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Katherine Raes
- Toxicology Center, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
| | - Markus Hecker
- Toxicology Center, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, 117 Science Place, Saskatoon, SK, S7N 5C8, Canada
| | - David Janz
- Toxicology Center, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada; Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4, Canada
| | - Lorne E Doig
- Toxicology Center, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3, Canada
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11
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Farell J, Wallschläger D. Determination of Se 8 in sediments by gas chromatography-mass spectrometry. Talanta 2018; 190:188-192. [PMID: 30172497 DOI: 10.1016/j.talanta.2018.07.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/22/2018] [Accepted: 07/24/2018] [Indexed: 11/16/2022]
Abstract
A gas chromatography-mass spectrometry (GC-MS) method was developed to analyze cyclooctaselenium (Se8) in sediments after extraction with carbon disulfide (CS2). The method suffers from some analytical complications, most notably a poor peak shape for Se8, manifesting in a broad peak (2 min) with strong fronting, and a decrease in Se8 retention time with decreasing concentration. Detailed analysis of the mass spectral data suggests that (thermal) decomposition of Se8 on the GC column is responsible for both of these phenomena. Despite these limitations, GC-MS with selected ion monitoring (SIM) yielded a sufficiently low detection limit, 10 µg/kg (dw), to analyze Se8 in selenium-impacted sediments. The CS2 extraction appears to be selective enough to allow the determination of Se8 in sediments without further cleanup when GC-SIM-MS is used for analysis. One selenium-impacted sediment contained 7.1 mg/kg (dw) Se8, corresponding to 41% of its total selenium and as much as 50% of its total elemental selenium. This is the first time that Se8 has been positively identified in the environment. Preliminary results also indicated the presence of mixed Se-S rings in this sediment.
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Affiliation(s)
- Jana Farell
- Environmental and Life Sciences Graduate Program, and Department of Chemistry, Trent University, 1600 West Bank Drive, Peterborough, Ontario, Canada K9J 7B8.
| | - Dirk Wallschläger
- Water Quality Centre, Environmental and Resource Science Program, and Department of Chemistry, Trent University, 1600 West Bank Drive, Peterborough, Ontario, Canada K9J 7B8
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12
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Boyer A, Hatat-Fraile M, Passeport E. Biogeochemical Controls on Strontium Fate at the Sediment-Water Interface of Two Groundwater-Fed Wetlands with Contrasting Hydrologic Regimes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8365-8372. [PMID: 29933694 DOI: 10.1021/acs.est.8b01876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Radioactive strontium (Sr) is a common groundwater contaminant at many nuclear sites. Its natural retention in groundwater-fed wetlands is an attractive remediation strategy. However, at present, the biogeochemical mechanisms controlling Sr transport at the sediment-water interface are poorly understood. In this field study, Sr fate was investigated in two wetlands with contrasting vegetation and hydrologic regimes. The marsh was an open-water wetland with constant water table and no emergent vegetation. The swamp was vegetated with fluctuating water levels and a thick mat of submerged cattail litter in the water column. High-resolution porewater Sr concentrations and solid-phase sediment Sr species revealed distinct profiles between the two wetlands. The marsh exhibited a strongly reduced environment and sharp concentration peaks at the sediment-water interface. In contrast, the smaller concentration gradients of the swamp resulted in a reduced flux of Sr to the surface water. The organic fraction of the sediment dominated Sr retention compared to the inorganic iron and manganese oxides. However, the marsh had a significant fraction of recalcitrant Sr presumably due to its incorporation into sulfur and/or carbonate minerals. These results suggest that vegetated wetlands with fluctuating hydrologic regimes could act as efficient sinks for Sr pollution.
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Affiliation(s)
- Antoine Boyer
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , 200 College Street , Toronto , M5S 3E5 , Canada
| | - Mélisa Hatat-Fraile
- Department of Civil and Mineral Engineering , University of Toronto , 35 St George St. , Toronto , M5S 1A4 , Canada
| | - Elodie Passeport
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , 200 College Street , Toronto , M5S 3E5 , Canada
- Department of Civil and Mineral Engineering , University of Toronto , 35 St George St. , Toronto , M5S 1A4 , Canada
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Martin AJ, Fraser C, Simpson S, Belzile N, Chen YW, London J, Wallschläger D. Hydrological and biogeochemical controls governing the speciation and accumulation of selenium in a wetland influenced by mine drainage. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:1824-1838. [PMID: 29480546 DOI: 10.1002/etc.4123] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/15/2018] [Accepted: 02/23/2018] [Indexed: 06/08/2023]
Abstract
Controls governing the speciation and accumulation of Se in a 3.7-ha marsh influenced by mine drainage were assessed through examination of water balance, water quality, sediment, and plant tissue components. Over the 8-mo study period (April through November, 2009), mean monthly flows ranged from 1600 to 2300 m3 d-1 (hydraulic retention time of 1-3 d). Total Se concentrations in the marsh outflow were lower than the inflow by 0.4 to 6.2 μg L-1 (mean difference = 3.3 μg L-1 ), illustrating Se removal. The Se accumulation pathways are illustrated by elevated concentrations of Se in sediments (3-35 mg kg-1 dry wt) as well as in below-ground (2-41 mg kg-1 dry wt; mean = 10 mg kg-1 dry wt) and above-ground (0.8-6.3 mg kg-1 dry wt; mean = 2 mg kg-1 dry wt) emergent plant tissues. Redox stratification in the shallow water column had a marked effect on Se speciation and behavior, illustrating bottom water removal of dissolved selenate in suboxic horizons and increased mobility of dissolved organo-Se. Mass balance data yielded inflow and outflow loading rates for Se of 27 and 23 g d-1 , respectively (net accumulation rate of 4 g d-1 or 0.11 mg m2 d-1 ). The rate of accumulation as calculated from the mass balance agrees with independently measured rates of Se accumulation in sediments for the site (3.6-8.1 g d-1 or 0.10-0.22 mg m-2 d-1 ). Environ Toxicol Chem 2018;37:1824-1838. © 2018 SETAC.
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Affiliation(s)
- Alan J Martin
- Lorax Environmental Services, Vancouver, British Columbia, Canada
| | - Colin Fraser
- Lorax Environmental Services, Vancouver, British Columbia, Canada
| | | | | | - Y-W Chen
- Laurentian University, Sudbury, Ontario, Canada
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Subedi G, Taylor J, Hatam I, Baldwin SA. Simultaneous selenate reduction and denitrification by a consortium of enriched mine site bacteria. CHEMOSPHERE 2017; 183:536-545. [PMID: 28570897 DOI: 10.1016/j.chemosphere.2017.05.144] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/23/2017] [Accepted: 05/24/2017] [Indexed: 06/07/2023]
Abstract
Increasing selenium concentrations in aquatic environments downstream of mine sites is of great concern due to selenium's bioaccumulation propensity and teratogenic toxicity. Removal of selenium from mine influenced water is complicated by the presence of nitrate, which is also elevated in mine influenced water due to the use of explosives in mining. In many biological treatment processes, nitrate as a thermodynamically more preferable electron acceptor inhibits selenate reduction. Here we report on an enrichment of a bacterial assemblage from a mine impacted natural marsh sediment that was capable of simultaneous selenate reduction and denitrification. Selenate reduction followed first order kinetics with respect to the concentration of total dissolved selenium. The kinetic rate constant was independent of initial nitrate concentration over the range 3-143 mg L-1-NO3--N. The initial concentration of selenate inhibited selenate reduction kinetics over the range 1-24 mg-Se L-1. Dominant taxa that grew in selenate only medium were classified in the genera Pseudomonas, Lysinibacillus and Thauera. When nitrate was introduced in addition to selenate, previously rare taxa that became dominant were relatives of Exiguobacterium, Tissierella and Clostridium. Open reading frames (ORFs) associated with dissimilatory denitrification were identified for Pseudomonas, Thauera and Clostridium. In addition, ORFs were found that were homologous with known selenate reductase subunits (SerA and SerB). These findings suggest that native mine site bacteria can be used for removing selenate and nitrate from mine wastewater.
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Affiliation(s)
- Gaurav Subedi
- Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Jon Taylor
- Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Ido Hatam
- Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Susan A Baldwin
- Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, British Columbia, V6T 1Z3, Canada.
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15
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Tang W, Dang F, Evans D, Zhong H, Xiao L. Understanding reduced inorganic mercury accumulation in rice following selenium application: Selenium application routes, speciation and doses. CHEMOSPHERE 2017; 169:369-376. [PMID: 27886539 DOI: 10.1016/j.chemosphere.2016.11.087] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 11/04/2016] [Accepted: 11/15/2016] [Indexed: 05/09/2023]
Abstract
Selenium (Se) has recently been demonstrated to reduce inorganic mercury (IHg) accumulation in rice plants, while its mechanism is far from clear. Here, we aimed at exploring the potential effects of Se application routes (soil or foliar application with Se), speciation (selenite and selenate), and doses on IHg-Se antagonistic interactions in soil-rice systems. Results of our pot experiments indicated that soil application but not foliar application could evidently reduce tissue IHg concentrations (root: 0-48%, straw: 15-58%, and brown rice: 26-74%), although both application routes resulted in comparable Se accumulation in aboveground tissues. Meanwhile, IHg distribution in root generally increased with amended Se doses in soil, suggesting antagonistic interactions between IHg and Se in root. These results provided initial evidence that IHg-Se interactions in the rhizosphere (i.e., soil or rice root), instead of those in the aboveground tissues, could probably be more responsible for the reduced IHg bioaccumulation following Se application. Furthermore, Se dose rather than Se speciation was found to be more important in controlling IHg accumulation in rice. Our findings regarding the importance of IHg-Se interactions in the rhizosphere, together with the systematic investigation of key factors affecting IHg-Se antagonism and IHg bioaccumulation, advance our understanding of Hg dynamics in soil-rice systems.
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Affiliation(s)
- Wenli Tang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
| | - Fei Dang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China.
| | - Douglas Evans
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China; Environmental and Resource Studies Program (ERS), Trent University, Peterborough, Ontario, Canada.
| | - Huan Zhong
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China; Environmental and Life Sciences Program (EnLS), Trent University, Peterborough, Ontario, Canada.
| | - Lin Xiao
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
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Zhang J, Liu J. DFT studies on structural properties and electron density topologies of the iron selenides Fe m Se n (1 ≤ m, n ≤ 4). RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2016. [DOI: 10.1134/s0036024416130094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Wang YJ, Dang F, Zhao JT, Zhong H. Selenium inhibits sulfate-mediated methylmercury production in rice paddy soil. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 213:232-239. [PMID: 26901075 DOI: 10.1016/j.envpol.2016.02.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 02/11/2016] [Accepted: 02/11/2016] [Indexed: 06/05/2023]
Abstract
There is increasing interest in understanding factors controlling methylmercury (MeHg) production in mercury-contaminated rice paddy soil. Sulfate has been reported to affect MeHg biogeochemistry under anoxic conditions, and recent studies revealed that selenium (Se) could evidently reduce MeHg production in paddy soil. However, the controls of sulfate and Se on net MeHg production in paddy soil under fluctuating redox conditions remain largely unknown. Microcosm experiments were conducted to explore the effects of sulfate and Se on net MeHg production in rice paddy soil. Soil was added with 0-960 mg/kg sulfate, in the presence or absence of 3.0 mg/kg selenium (selenite or selenate), and incubated under anoxic (40 days) or suboxic conditions (5 days), simulating fluctuating redox conditions in rice paddy field. Sulfate addition moderately affected soil MeHg concentrations under anoxic conditions, while reoxidation resulted in evidently higher (18-40%) MeHg levels in sulfate amended soils than the control. The observed changes in net MeHg production were related to dynamics of sulfate and iron. However, Se could inhibit sulfate-mediated MeHg production in the soils: Se addition largely reduced net MeHg production in the soils (23-86%, compared to the control), despite of sulfate addition. Similarly, results of the pot experiments (i.e., rice cultivation in amended soils) indicated that soil MeHg levels were rather comparable in Se-amended soils during rice growth period, irrespective of added sulfate doses. The more important role of Se than sulfate in controlling MeHg production was explained by the formation of HgSe nanoparticles irrespective of the presence of sulfate, confirmed by TEM-EDX and XANES analysis. Our findings regarding the effects of sulfate and Se on net MeHg production in rice paddy soil together with the mechanistic explanation of the processes advance our understanding of MeHg dynamics and risk in soil-rice systems.
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Affiliation(s)
- Yong-Jie Wang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Fei Dang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China
| | - Jia-Ting Zhao
- Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Laboratory of Metallomics and Metalloproteomics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Huan Zhong
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China; Environmental and Life Sciences Program (EnLS), Trent University, Peterborough, Ontario, Canada.
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18
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Ponton DE, Hare L. Using Sulfur Stable Isotopes to Understand Feeding Behavior and Selenium Concentrations in Yellow Perch (Perca flavescens). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:7633-7640. [PMID: 26020463 DOI: 10.1021/acs.est.5b00718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We measured selenium (Se) concentrations in yellow perch (Perca flavescens) muscle and their prey collected from four Se-contaminated lakes located near metal smelters in the eastern Canadian cities of Sudbury and Rouyn-Noranda. Yellow perch Se concentrations were related to their weight in two of the four lakes. Measurements of sulfur stable isotopes (δ(34)S) in yellow perch muscle and stomach contents showed that larger fish tended to feed less on zooplankton and more on benthic invertebrates than did smaller fish. Because Se concentrations are lower and δ(34)S signatures are higher in zooplankton than in sediment-feeding invertebrates, there was an inverse relationship between animal Se concentrations and δ(34)S signatures in all of our study lakes. δ(34)S signatures were highly effective in characterizing these food web relationships. Selenium concentrations in yellow perch were 1.6 times those of its prey, which indicates that Se is biomagnified by this fish in our study lakes. Estimated Se concentrations in yellow perch gonads suggest that in two of our study lakes one-third of fish are at risk of reproductive toxicity.
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Affiliation(s)
- Dominic E Ponton
- Institut national de la recherche scientifique, Centre - Eau Terre Environnement (INRS-ETE), Université du Québec, 490 rue de la Couronne, Quebec City, QC, Canada G1K 9A9
| | - Landis Hare
- Institut national de la recherche scientifique, Centre - Eau Terre Environnement (INRS-ETE), Université du Québec, 490 rue de la Couronne, Quebec City, QC, Canada G1K 9A9
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19
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Li DB, Cheng YY, Wu C, Li WW, Li N, Yang ZC, Tong ZH, Yu HQ. Selenite reduction by Shewanella oneidensis MR-1 is mediated by fumarate reductase in periplasm. Sci Rep 2014; 4:3735. [PMID: 24435070 PMCID: PMC3894562 DOI: 10.1038/srep03735] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 12/05/2013] [Indexed: 11/09/2022] Open
Abstract
In situ reduction of selenite to elemental selenium (Se(0)), by microorganisms in sediments and soils is an important process and greatly affects the environmental distribution and the biological effects of selenium. However, the mechanism behind such a biological process remains unrevealed yet. Here we use Shewanella oneidensis MR-1, a widely-distributed dissimilatory metal-reducing bacterium with a powerful and diverse respiration capability, to evaluate the involvement of anaerobic respiration system in the microbial selenite reduction. With mutants analysis, we identify fumarate reductase FccA as the terminal reductase of selenite in periplasm. Moreover, we find that such a reduction is dependent on central respiration c-type cytochrome CymA. In contrast, nitrate reductase, nitrite reductase, and the Mtr electron transfer pathway do not work as selenite reductases. These findings reveal a previously unrecognized role of anaerobic respiration reductases of S. oneidensis MR-1 in selenite reduction and geochemical cycles of selenium in sediments and soils.
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Affiliation(s)
- Dao-Bo Li
- 1] School of Earth and Space Sciences [2] Department of Chemistry [3]
| | | | | | | | | | - Zong-Chuang Yang
- School of Life Sciences, University of Science & Technology of China, Hefei, 230026, China
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20
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Liu YT, Chen TY, Mackebee WG, Ruhl L, Vengosh A, Hsu-Kim H. Selenium speciation in coal ash spilled at the Tennessee Valley Authority Kingston site. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:14001-9. [PMID: 24266628 DOI: 10.1021/es4041557] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Selenium (Se) in coal ash spills poses a threat to adjacent ecosystems because of its potential to mobilize and bioaccumulate in aquatic organisms. Given that the mobility and bioavailability of Se is controlled by its valence states, we aimed to define Se speciation in coal ash solids and examine the relationships between Se speciation and the magnitude of its mobilization from coal ash. We used coal ash samples from the Tennessee Valley Authority (TVA)-Kingston fossil plant and the site of a coal ash spill that occurred in 2008 in Tennessee. Results of X-ray absorption spectroscopic analyses showed that Se in coal ash samples was a mixture of elemental Se(0) and Se oxyanions. The amount of leachable Se increased with an increase of pH from 3 to 13. At the natural pH of coal ash samples (from pH 7.6 to 9.5), the leachable Se was comprised of Se oxyanions, mainly selenite. This was observed by both direct quantification of Se oxyanions in the leachate and the corresponding loss of Se oxyanions in the solid phase. At pH 12, however, the Se release appeared to derive from both desorption of Se oxyanions and oxidative dissolution of elemental Se(0). Our results indicate that Se oxyanions are the most labile species; however, the magnitude of Se mobilization will increase if the waste material is subjected to alkaline conditions.
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Affiliation(s)
- Yu-Ting Liu
- Department of Civil and Environmental Engineering, 121 Hudson Hall, Box 90287, Duke University , Durham, North Carolina 27708, United States
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21
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Franz ED, Wiramanaden CIE, Gallego-Gallegos M, Tse JJ, Phibbs J, Janz DM, Pickering IJ, Liber K. An in situ assessment of selenium bioaccumulation from water-, sediment-, and dietary-exposure pathways using caged Chironomus dilutus larvae. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:2836-2848. [PMID: 23996699 DOI: 10.1002/etc.2382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/07/2013] [Accepted: 08/22/2013] [Indexed: 06/02/2023]
Abstract
An in situ caging study was conducted downstream of a metal mine in northern Canada to determine the significance of surface water versus sediment exposure on selenium (Se) bioaccumulation in the benthic invertebrate Chironomus dilutus. Laboratory-reared C. dilutus larvae were exposed to either site-specific whole-sediment and surface water or surface water only for 10 d at sites with differing sediment and Se characteristics. Results showed elevated whole-body Se concentrations in C. dilutus larvae when exposed to sediment and water, compared with larvae exposed to Se in the surface water only at concentrations ranging from <1 µg Se/L to 12 µg Se/L. In response to these findings, a second in situ experiment was conducted to investigate the importance of dietary Se (biofilm and detritus) versus whole-sediment-exposure pathways. Larvae exposed to sediment detritus had the highest Se concentrations after 10 d of exposure (15.6 ± 1.9 µg/g dry wt) compared with larvae exposed to whole-sediment (12.9 ± 1.7 µg/g dry wt) or biofilm (9.9 ± 1.6 µg/g dry wt). Detritus and biofilm appear to be enriched sources of organic Se, which are more bioaccumulative than inorganic Se. Midge larvae from the reference treatment contained elevated concentrations of diselenides (i.e., selenocystine), while larvae from the biofilm treatment had the highest concentrations of selenomethionine-like compounds, which may be a biomarker of elevated Se exposures derived from anthropogenic sources. Whenever possible, Se concentrations in the organic fraction of sediment should be measured separately from whole-sediment Se and used for more accurate ecological risk assessments of potential Se impacts on aquatic ecosystems.
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Affiliation(s)
- Eric D Franz
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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22
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Misra S, Kwong RWM, Niyogi S. Transport of selenium across the plasma membrane of primary hepatocytes and enterocytes of rainbow trout. ACTA ACUST UNITED AC 2012; 215:1491-501. [PMID: 22496285 DOI: 10.1242/jeb.062307] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Transport of essential solutes across biological membranes is one of the fundamental characteristics of living cells. Although selenium is an essential micronutrient, little is known about the cellular mechanisms of chemical species-specific selenium transport in fish. We report here the kinetic and pharmacological transport characteristics of selenite and its thiol (glutathione and l-cysteine) derivatives in primary cultures of hepatocytes and isolated enterocytes of rainbow trout. Findings from the current study suggest an apparent low-affinity linear transport system for selenite in both cell types. However, we recorded high-affinity Hill kinetics (K(d)=3.61±0.28 μmol l(-1)) in enterocytes exposed to selenite in the presence of glutathione. The uptake of selenite in the presence of thiols was severalfold higher than uptake of selenite alone (at equimolar concentration) in both hepatocytes and enterocytes. Cellular accumulation of selenium was found to be energy independent. Interestingly, we observed a decrease in selenite transport with increasing pH, whereas selenite uptake increased with increasing pH in the presence glutathione in both cell types. The cellular uptake of selenite demonstrated a pronounced competitive interaction with a structurally similar compound, sulfite. The uptake of selenite as well as its thiol derivatives was found to be sensitive to the anion transport blocker DIDS, irrespective of the cell type. Inorganic mercury (Hg(2+)) elicited an inhibition of selenite transport in both cell types, but augmented the transport of reduced forms of selenite in hepatocytes. Based on the substrate choice and comparable pharmacological properties, we advocate that multiple anion transport systems are probably involved in the cellular transport of selenite in fish.
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Affiliation(s)
- Sougat Misra
- Department of Biology, 112 Science Place, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 5E2
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Couture RM, Sekowska A, Fang G, Danchin A. Linking selenium biogeochemistry to the sulfur-dependent biological detoxification of arsenic. Environ Microbiol 2012; 14:1612-23. [DOI: 10.1111/j.1462-2920.2012.02758.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Orr PL, Wiramanaden CIE, Paine MD, Franklin W, Fraser C. Food chain model based on field data to predict westslope cutthroat trout (Oncorhynchus clarkii lewisi) ovary selenium concentrations from water selenium concentrations in the Elk Valley, British Columbia. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2012; 31:672-680. [PMID: 22189838 DOI: 10.1002/etc.1730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 07/20/2011] [Accepted: 11/03/2011] [Indexed: 05/31/2023]
Abstract
Previous studies conducted in the Elk River watershed showed that selenium concentrations are higher in aquatic biota in lentic compared to lotic habitats of the system having similar water selenium concentrations. Studies have also shown that water selenium concentrations have increased over time (~10% per year) and recent annual average concentrations have ranged up to 0.044 mg/L in areas downstream from mine discharges. For the present study, trophic transfer of selenium was characterized in lotic versus lentic habitats using concentrations measured in field-collected samples and assuming a three-step food chain of water to the base of the food web (biofilm), to benthic invertebrates, and then to westslope cutthroat trout (WCT) ovaries. Food chain models were developed for each habitat type (lotic and lentic) by combining linear regression equations for the three transfer relationships, allowing for prediction of fish ovary concentrations from water concentrations. Greater accumulation of selenium in lentic areas was mostly attributable to greater uptake at the base of the food chain compared to lotic areas. Enrichment/trophic transfer factors for selenium at all levels of the lotic and lentic food chains decreased and then became near constant as exposure concentrations increased. The lotic model predicted little increase in WCT ovary selenium concentrations over an eightfold increase in water concentrations (~0.005-0.040 mg/L), accounting for the lack of observed increase in within-area fish tissue concentrations over time despite increasing trends in water concentrations.
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Affiliation(s)
- P L Orr
- Minnow Environmental, Georgetown, Ontario, Canada.
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25
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Franz ED, Wiramanaden CIE, Janz DM, Pickering IJ, Liber K. Selenium bioaccumulation and speciation in Chironomus dilutus exposed to water-borne selenate, selenite, or seleno-DL-methionine. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:2292-2299. [PMID: 21766323 DOI: 10.1002/etc.624] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/06/2011] [Accepted: 06/03/2011] [Indexed: 05/31/2023]
Abstract
The objective of the present study was to describe the uptake and elimination kinetics of selenium (Se) administered in the forms of selenate, selenite, and selenomethionine (seleno-DL-methionine) in different life stages of the midge Chironomus dilutus, and to determine the relationship between Se bioavailability and Se speciation using X-ray absorption spectroscopy (XAS). Midge larvae exposed to 4.3 µg/L as dissolved selenate for 10 d of had negligible accumulation of Se (indistinguishable from control organisms). However, larvae rapidly accumulated Se over 10 d of exposure to 3.8 and 1.8 µg/L selenite and seleno-DL-methionine (Se-met), respectively. Most Se accumulated by larvae exposed to selenite or Se-met was retained after 10 d of elimination in clean water. When additional midge larvae were exposed to Se until emergence, Se accumulated during the larval stage was largely retained in the adults. Although a strong correlation was found between the adult whole-body Se concentration and the Se concentration in the exuvia after emergence, only a minor loss of Se occurred in the shed exuvia compared with larvae and adult whole-body concentrations. X-ray absorption spectroscopy analysis showed that organic selenides and diselenides, modeled as Se-met and selenocystine, respectively, were the dominant forms of Se in both the larval and adult insect stages. The proportion and concentration of organic selenides (selenomethionine) increased in larvae and adults exposed to Se-met and selenite compared with larvae exposed to selenate, whereas the concentration of diselenides (selenocystine) remained relatively constant for all treatments.
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Affiliation(s)
- Eric D Franz
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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