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Martinez-Alesón García P, García-Balboa C, López-Rodas V, Costas E, Baselga-Cervera B. Settling selection of Chlamydomonas reinhardtii for samarium uptake. JOURNAL OF PHYCOLOGY 2024; 60:755-767. [PMID: 38738959 DOI: 10.1111/jpy.13461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 03/07/2024] [Accepted: 04/06/2024] [Indexed: 05/14/2024]
Abstract
Samarium (Sm) is a rare-earth element recently included in the list of critical elements due to its vital role in emerging new technologies. With an increasing demand for Sm, microbial bioremediation may provide a cost-effective and a more ecologically responsible alternative to remove and recover Sm. We capitalized on a previously selected Chlamydomonas reinhardtii strain tolerant to Sm (1.33 × 10-4 M) and acidic pH and carried out settling selection to increase the Sm uptake performance. We observed a rapid response to selection in terms of cellular phenotype. Cellular size decreased and circularity increased in a stepwise manner with every cycle of selection. After four cycles of selection, the derived CSm4 strain was significantly smaller and was capable of sequestrating 41% more Sm per cell (1.7 × 10-05 ± 1.7 × 10-06 ng) and twice as much Sm in terms of wet biomass (4.0 ± 0.4 mg Sm · g-1) compared to the ancestral candidate strain. The majority (~70%) of the Sm was bioaccumulated intracellularly, near acidocalcisomes or autophagic vacuoles as per TEM-EDX microanalyses. However, Sm analyses suggest a stronger response toward bioabsorption resulting from settling selection. Despite working with Sm and pH-tolerant strains, we observed an effect on fitness and photosynthesis inhibition when the strains were grown with Sm. Our results clearly show that phenotypic selection, such as settling selection, can significantly enhance Sm uptake. Laboratory selection of microalgae for rare-earth metal bioaccumulation and sorption can be a promising biotechnological approach.
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Affiliation(s)
- Paloma Martinez-Alesón García
- Pharmaceutical and Health Sciences Department, Faculty of Pharmacy, University San Pablo CEU, Madrid, Spain
- Animal Science (Genetics), School of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Camino García-Balboa
- Animal Science (Genetics), School of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Victoria López-Rodas
- Animal Science (Genetics), School of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Eduardo Costas
- Animal Science (Genetics), School of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Beatriz Baselga-Cervera
- Ecology, Evolution and Behavior Department, University of Minnesota, St. Paul, Minnesota, USA
- Minnesota Center for Philosophy of Science, University of Minnesota, Minneapolis, Minnesota, USA
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2
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Li S, Yang B, Wang M, Zhang R, Chen K, He Z, Shi H, Chen S. Environmental quality standards for agricultural land in China: What should be improved on derivation methodology? JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 324:116334. [PMID: 36352708 DOI: 10.1016/j.jenvman.2022.116334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 08/31/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
Soil pollution has caused increasingly widespread attention in China. The environmental risk threshold of pollutants is a yardstick to measure soil environmental quality. For decades, plenty of research on soil environmental quality standards (SEQSs) has been carried out, providing scientific basis for the investigation and supervision of soil environmental quality. This paper summaries the development of SEQSs in China, the corresponding influencing factors and methodology of SEQSs derivation. In the current version of SEQSs (GB15618-2018), the thresholds of soil pollutants are derived by the methods of environmental risk assessment, which are more methodologically scientific than geochemical method and ecological effect method used in the previous version (GB15618-1995). Abundant toxicology data on related species is required for risk assessment of soil pollution using extrapolation; however, basic toxicological data is insufficient and few valid data is available at present. Besides, the inadequate consideration on influencing factors for the derivation of soil pollutant threshold would affect the scientificity and rationality of SEQSs, such as biotic factors (species type, test endpoint etc.) and abiotic factors (aging effect, leaching effect, synergistic or antagonistic effects of elements etc.). These problems should be paid close attention in future research on soil environmental quality standards. The contents summarized in this review may provide reference for decision-making on supervision of soil environmental quality and point out important directions for future studies.
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Affiliation(s)
- Shanshan Li
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China
| | - Bing Yang
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China
| | - Meng Wang
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/ Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China
| | - Rong Zhang
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China
| | - Kun Chen
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China
| | - Zexin He
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China
| | - Huading Shi
- Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, 100012, PR China.
| | - Shibao Chen
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/ Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, PR China.
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3
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Kochoni E, Doose C, Gonzalez P, Fortin C. Role of iron in gene expression and in the modulation of copper uptake in a freshwater alga: Insights on Cu and Fe assimilation pathways. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 305:119311. [PMID: 35439593 DOI: 10.1016/j.envpol.2022.119311] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/21/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
Metal uptake and toxicity can generally be related to its aqueous speciation and to the presence of competitive ions as described by the biotic ligand model. Beyond these simple chemical interactions at the surface of aquatic organisms, several internal biological feedback mechanisms can also modulate metal uptake. This is particularly important for essential elements for which specific transport systems were developed over the course of evolution. Based on the results of short-term Cu2+ uptake experiments and on the analysis of the expression of certain genes involved in Cu and Fe homeostasis, we studied the effects of Fe3+ on Cu2+ uptake by the freshwater green alga Chlamydomonas reinhardtii. We observed a significant increase in Cu2+ uptake rate in algal cells acclimated to a low Fe3+ medium up to 4.7 times greater compared to non-acclimated algal cells. The overexpression of the ferroxidase FOX1 and permease FTR1 genes suggests an activation of the high affinity Fe3+ assimilation system, which could constitute a plausible explanation for the increase in Cu2+ uptake rate in acclimatized algae. We show that Fe availability can have a significant impact on Cu uptake. Our observations reinforce the importance of considering physiological factors to better predict metal bioavailability.
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Affiliation(s)
- Emeric Kochoni
- EcotoQ, Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC, G1K 9A9, Canada
| | - Caroline Doose
- Laboratoire de Biologie des Organismes et des écosystèmes Aquatiques, Muséum National d'Histoire Naturelle, Station Marine Concarneau, 29900, Concarneau, France
| | - Patrice Gonzalez
- Université de Bordeaux, CNRS, EPOC, EPHE, UMR 5805, 33600, Pessac, France
| | - Claude Fortin
- EcotoQ, Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC, G1K 9A9, Canada.
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4
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Aharchaou I, Bahloul F, Fortin C. Competition Among Trivalent Elements (Al, Eu, Fe, Gd, Nd, Tm, and Y) for Uptake in Algae and Applicability of the Biotic Ligand Model. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2021; 81:612-620. [PMID: 33219836 DOI: 10.1007/s00244-020-00786-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
Rare earth elements (REE) are essential in many new technologies. While anthropogenic dispersion of REE into the environment are expected in the future, their biogeochemical fate and interactions at biological interfaces are still largely unexplored. Due to their chemical nature (generally trivalent and hard metals), REE can potentially compete among themselves or with other ubiquitous trivalent metals for uptake sites at the surface of aquatic organisms. In the current study, the bioavailability and uptake of gadolinium (Gd) was assessed in the green alga, Chlamydomonas reinhardtii, while in the presence of various trivalent elements (Al, Eu, Fe, Nd, Tm, and Y). In the absence of competitors, Gd uptake was well described by a Michaelis-Menten equation with an affinity constant (KGd) of 107.1 and a maximum internalization flux (Jmax) of 1.95 ± 0.09 × 10-2 amol µm-2 min-1. Neither Al(III) nor Fe(III) had notable effects on Gd uptake in the conditions tested; however, Gd uptake was reduced with increasing concentrations of other REE. These had binding constants with uptake sites very similar to that of Gd (KNd, Y, Tm, Eu = 107.0). Our results suggest that the different REE likely share common transport sites and that the biotic ligand model (BLM) can be used to predict their uptake.
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Affiliation(s)
- I Aharchaou
- ÉcotoQ, Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC, G1K 9A9, Canada
| | - F Bahloul
- ÉcotoQ, Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC, G1K 9A9, Canada
| | - C Fortin
- ÉcotoQ, Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC, G1K 9A9, Canada.
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5
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Laderriere V, Le Faucheur S, Fortin C. Exploring the role of water chemistry on metal accumulation in biofilms from streams in mining areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 784:146986. [PMID: 33894602 DOI: 10.1016/j.scitotenv.2021.146986] [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: 02/26/2021] [Revised: 04/03/2021] [Accepted: 04/04/2021] [Indexed: 06/12/2023]
Abstract
Biofilms play a key role in aquatic ecosystems. They are ubiquitous, even in the most contaminated ecosystems, and have great potential as biomonitors of exposure to contaminants such as metals. Freshwater biofilms and surface waters were sampled in two active mining areas of Canada: in the northern part of Nunavik (Quebec) and in the Greater Sudbury area (Ontario). Significant linear relationships were found between both total dissolved and free metal ion concentrations with biofilm metal contents for Cu and Ni, but not for Cd. When pH was below 6, biofilms accumulated less metals than at higher pHs. These results confirm that protons have a protective effect, leading to lower internalized metal concentrations. When considering only the sites where pH was above 6, the linear relationships between metal concentrations in water and in biofilms were improved for all three studied metals. The presence of metal ions could also modify the internalization of a given metal. To further study the role of cations as competitors to Cu, Ni and Cd uptake, relationships between the ratio of biofilm metal contents (Cu, Ni and Cd) on the ambient free metal ion concentrations were built as a function of potential cation competitors, such as major cations and metals. Surprisingly, our data suggest that calcium plays a minor role in preventing metal accumulation as compared to magnesium and possibly other metals. At a global scale, metal accumulation remained highly consistent between the two studied regions and over the sampling period, despite differences in ambient physicochemical water characteristics, climate or types of ecosystems. Metal bioaccumulation is thus a promising biomarker to assess metal bioavailability in a mining context. Nevertheless, more data are still required to further highlight the contribution of each competitor in metal accumulation by biofilms and to be able to build a unifying predictive model.
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Affiliation(s)
- Vincent Laderriere
- Institut national de la recherche scientifique, Centre Eau Terre Environnement, 490 rue de la Couronne, Québec, Canada
| | - Séverine Le Faucheur
- Université de Pau et des Pays de l'Adour, e2s-UPPA, IPREM, 2 avenue Pierre Angot, Pau, France
| | - Claude Fortin
- Institut national de la recherche scientifique, Centre Eau Terre Environnement, 490 rue de la Couronne, Québec, Canada.
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6
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Gong B, He E, Xia B, Ying R, Peijnenburg WJGM, Liu Y, Qiu H. Bioavailability and phytotoxicity of rare earth metals to Triticum aestivum under various exposure scenarios. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 205:111346. [PMID: 32977285 DOI: 10.1016/j.ecoenv.2020.111346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
It is a daunting challenge to predict toxicity and accumulation of rare earth metals (REMs) in different exposure scenarios (e.g., varying water chemistry and metal combinations). Herein, we investigated the toxicity and uptake of La and Ce in the presence of various levels of Ca, Mg, Na, K, and at different pH values, as well as the combined effects of La and Ce in wheat Triticum aestivum. Major cations (Ca2+ and Mg2+) significantly mitigated the toxicity and accumulation of La3+/Ce3+. Toxicity and uptake of La, Ce, and La-Ce mixtures could be well quantified by the multi-metal biotic ligand model (BLM) and by the Langmuir-type uptake model with the consideration of the competitive effects of Ca2+ and Mg2+, with more than 85.1% of variations explained. The derived binding constants of Ca, Mg, La, and Ce to wheat root were respectively 3.87, 3.59, 6.97, and 6.48 on the basis of toxicity data, and 3.23, 2.84, 6.07, and 5.27 on the basis of uptake data. The use of the alternative WHAM-Ftox approach, requiring fewer model parameters than the BLM but with similar Akaike information criterion (AIC) values, successfully predicted the toxicity and accumulation of La/Ce as well as toxicity of La-Ce mixtures, with at least 76.4% of variations explained. However, caution should be taken when using this approach to explain the uptake of La-Ce mixtures. Our results provided promising tools for delineating REMs toxicity/uptake in the presence of other toxicity-modifying factors or in mixture scenarios.
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Affiliation(s)
- Bing Gong
- School of Geographic Sciences, East China Normal University, Shanghai, 200241, China; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Erkai He
- School of Geographic Sciences, East China Normal University, Shanghai, 200241, China.
| | - Bing Xia
- Anhui Academy of Environmental Science Research, Hefei, 230051, China
| | - Rongrong Ying
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Willie J G M Peijnenburg
- Institute of Environmental Sciences, Leiden University, Leiden, 2333CC, the Netherlands; National Institute of Public Health and the Environment, Center for the Safety of Substances and Products, Bilthoven 3720 BA, the Netherlands
| | - Yang Liu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China
| | - Hao Qiu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
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7
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Aharchaou I, Beaubien C, Campbell PGC, Fortin C. Lanthanum and Cerium Toxicity to the Freshwater Green Alga Chlorella fusca: Applicability of the Biotic Ligand Model. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2020; 39:996-1005. [PMID: 32135577 DOI: 10.1002/etc.4707] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/11/2019] [Accepted: 03/04/2020] [Indexed: 05/25/2023]
Abstract
The environmental risk assessment of rare earth elements (REEs) requires data on their potential toxicity. In the present study, the toxicity of lanthanum (La) and cerium (Ce) was studied in relation to metal speciation in solution. For both La and Ce, the use of organic ligands demonstrated that the calculated free ion concentration was a good indicator of toxicity. Whether in the absence or presence of organic ligands, when based on free ion concentrations, the obtained half-maximal effective concentrations were similar. When all generated data were pooled, Ce and La showed identical toxicity thresholds after 120 h of exposure with free ion concentration-based median effective concentration values (95% confidence intervals) of 0.48 (0.38-0.60) µM and 0.47 (0.36-0.61) µM for La3+ and Ce3+ , respectively. The inhibition of algal growth was also correlated with the intracellular lanthanide concentrations, regardless of the ligand used. Finally, increasing the ambient calcium concentration protected the test algae by reducing the amount of lanthanide internalized into the cells. These results suggest that, at constant pH (5.5), REE accumulation and toxicity are linked to the free ion concentration and ambient calcium concentration, as predicted by the biotic ligand model. Environ Toxicol Chem 2020;39:996-1005. © 2020 SETAC.
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Affiliation(s)
- Imad Aharchaou
- EcotoQ, Institut national de la Recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
| | - Cédrick Beaubien
- EcotoQ, Institut national de la Recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
| | - Peter G C Campbell
- EcotoQ, Institut national de la Recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
| | - Claude Fortin
- EcotoQ, Institut national de la Recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
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8
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Aziz N, Butt A, Elsheikha HM. Antioxidant enzymes as biomarkers of Cu and Pb exposure in the ground spiders Lycosa terrestris and Pardosa birmanica. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 190:110054. [PMID: 31864121 DOI: 10.1016/j.ecoenv.2019.110054] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/07/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
Heavy metal exposure induces oxidative stress in terrestrial organisms, which they counteract via activation of antioxidant biomarkers. The present study investigated the effects of copper (Cu) and lead (Pb) on the total antioxidant capacity (TAC) and antioxidant enzymes such as Catalase (CAT), Glutathione reductase (GR), Superoxide dismutase (SOD) and Glutathione peroxidase (GPX) in two spider species, namely Lycosa terrestris and Pardosa birmanica. The spiders were exposed to Cu and Pb separately (10 ppm) or in combination (10 ppm each) via two different exposure routes (i.e. food and soil) for 10, 20 and 40 days. The results showed that metal accumulation and antioxidant biomarker responses in spiders were metal- and species-dependent. Also, the levels of all antioxidant biomarkers increased significantly with increasing exposure time and metal load in the bodies of spiders via both exposure routes. The significant inhibition of TAC and antioxidant enzyme activities was only observed in single Pb treatment through soil exposure. In L. terrestris, the activities of detoxification enzymes and TAC were significantly enhanced on single Cu exposure than Pb via both exposure routes. However, in P. birmanica consistent variation among antioxidant parameters were observed depending on the metal load and exposure routes. The combined metal exposure caused more pronounced increase in the level of antioxidants compared to single metal exposure in both species, mainly via food exposure. These results suggest that the antioxidant enzymes and TAC are sensitive to single and combined metal exposure via both uptake routes. These data show that antioxidant parameters can be used potential biomarkers of oxidative stress associated with metal exposure and for monitoring environmental health using spiders as bioindicators.
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Affiliation(s)
- Nida Aziz
- Department of Zoology, University of the Punjab, Lahore, Pakistan; Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - Abida Butt
- Department of Zoology, University of the Punjab, Lahore, Pakistan.
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
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Li L, Zhang Y, Ippolito JA, Xing W, Qiu K, Yang H. Lead smelting effects heavy metal concentrations in soils, wheat, and potentially humans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113641. [PMID: 31767230 DOI: 10.1016/j.envpol.2019.113641] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 11/08/2019] [Accepted: 11/16/2019] [Indexed: 05/09/2023]
Abstract
Cadmium, Cu, Pb and Zn concentrations and distribution in soil, wheat, and the potential for human heavy metal accumulation near a Pb smelting affected area were investigated. Farm land soil, wheat grain and scalp hair samples were collected from three villages (named QD, GF and BS) with increasing distance from a large Pb smelter in China. Soil Cd and Pb concentrations exceeded national standards 46-100% of the time, depending on location. Soil and wheat grain Cd, Cu, Pb and Zn concentrations increased as distance to the smelter decreased. Similarly, greater Cd, Cu and Pb concentrations were present in human scalp hair for those residents living closest to the smelter. Decreasing trends existed for hair-to-wheat grain ratios for Cd and Pb as distance to the smelter increased. Results suggest that as distance to the smelter decreases, human heavy metal absorption via the consumption of metal-contaminated food products (e.g., wheat) increases.
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Affiliation(s)
- Liping Li
- School of Chemistry and the Environment, Henan University of Technology, Zhengzhou, Henan, 450001, China.
| | - Yuqing Zhang
- School of Chemistry and the Environment, Henan University of Technology, Zhengzhou, Henan, 450001, China
| | - James A Ippolito
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523-1170, USA
| | - Weiqin Xing
- School of Chemistry and the Environment, Henan University of Technology, Zhengzhou, Henan, 450001, China
| | - Kunyan Qiu
- Key Laboratory for Monitoring and Remediation of Heavy Metal Polluted Soils of Henan Province, Jiyuan, Henan, 459000, China
| | - Hao Yang
- School of Chemistry and the Environment, Henan University of Technology, Zhengzhou, Henan, 450001, China
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10
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Wang WX, Tan QG. Applications of dynamic models in predicting the bioaccumulation, transport and toxicity of trace metals in aquatic organisms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 252:1561-1573. [PMID: 31277025 DOI: 10.1016/j.envpol.2019.06.043] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/08/2019] [Accepted: 06/11/2019] [Indexed: 06/09/2023]
Abstract
This review evaluates the three dynamic models (biokinetic model: BK, physiologically based pharmacokinetic model: PBPK, and toxicokinetic-toxicodynamic model: TKTD) in our understanding of the key questions in metal ecotoxicology in aquatic systems, i.e., bioaccumulation, transport and toxicity. All the models rely on the first-order kinetics principle of metal uptake and elimination. The BK model basically treats organisms as a single compartment, and is both physiologically and geochemically based. With a good understanding of each kinetic parameter, bioaccumulation of metals in any aquatic organisms can be studied holistically and mechanistically. Modeling efforts are not merely restrained from the prediction of metal accumulation in the tissues, but instead provide the direction of the key processes that need to be addressed. PBPK is more physiologically based since it mainly addresses the transportation, transformation and distribution of metals in the organisms. It can be treated conceptually as a multi-compartmental kinetic model, whereas the physiology is driving the development of any good PBPK model which is no generic for aquatic animals and contaminants. There are now increasingly applications of the PBPK modeling specifically in metal studies, which reveal many important processes that are impossible to be teased out by direct experimental measurements without adequate modeling. TKTD models further focus on metal toxicity in addition to metal bioaccumulation. The TK part links exposure and bioaccumulation, while the TD part links bioaccumulation and toxic effects. The separation of TK and TD makes it possible to model processes, e.g., toxicity modification by environmental factors, interaction between different metals, at both the toxicokinetic and toxicodynamic levels. TKTD models provide a framework for making full use of metal toxicity data, and thus provide more information for environmental risk assessments. Overall, the three models reviewed here will continue to provide guiding principles in our further studies of metal bioaccumulation and toxicity in aquatic organisms.
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Affiliation(s)
- Wen-Xiong Wang
- Department of Ocean Science, The Hong Kong University of Science and Technology (HKUST), Clearwater Bay, Kowloon, Hong Kong; HKUST Shenzhen Research Institute, Shenzhen, 518057, China.
| | - Qiao-Guo Tan
- Center for Marine Environmental Chemistry and Toxicology, Key Laboratory of the Coastal and Wetland Ecosystems of Ministry of Education, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
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11
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Crémazy A, Brix KV, Wood CM. Using the Biotic Ligand Model framework to investigate binary metal interactions on the uptake of Ag, Cd, Cu, Ni, Pb and Zn in the freshwater snail Lymnaea stagnalis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 647:1611-1625. [PMID: 30180365 DOI: 10.1016/j.scitotenv.2018.07.455] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 06/08/2023]
Abstract
There is growing interest in the development of mechanistically-based models, such as the Biotic Ligand Model (BLM), for assessing the environmental risk of metal mixtures. However, the derivation of such models requires insights into the mechanisms of multimetal interactions that are often lacking for aquatic organisms. In the present study, we investigated how binary mixtures of six metals (Ag, Cd, Cu, Ni, Pb and Zn) interact for uptake in the great pond snail Lymnaea stagnalis, a freshwater species particularly sensitive to metals in chronic exposure. For each metal, short-term (2-3 h) uptake experiments on juvenile snails were performed with the metal alone and in combination with a second metal, at concentrations encompassing the chronic toxicity concentration range. These experiments showed significant binary metal interactions for 7 out of 15 mixtures. Most interactions were inhibitory in nature, not reciprocal and caused by either Ag or Cu. They led to relative changes of uptake that did not exceed 50% within the range of metal chronic toxicity. The BLM proved to be successful at explaining most of the interactions, via competitive inhibition. This study is in support of using bioavailability-based models, such as the BLM, to model metal mixture interactions in L. stagnalis.
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Affiliation(s)
- Anne Crémazy
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | | | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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12
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Lavoie M, Duval JFL, Raven JA, Maps F, Béjaoui B, Kieber DJ, Vincent WF. Carbonate Disequilibrium in the External Boundary Layer of Freshwater Chrysophytes: Implications for Contaminant Uptake. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9403-9411. [PMID: 30016087 DOI: 10.1021/acs.est.8b00843] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The interplay between biological and chemical reactions in the freshwater phytoplankton phycosphere and the resulting modulations of contaminant speciation and uptake is poorly characterized. Here we modeled the effect of algal C and N uptake on carbonate cycling and speciation of selected contaminants in the phycosphere (external boundary layer) of chrysophytes, a key phytoplankton group in oligotrophic systems. We calculated an enrichment in H+ concentration relative to that in the bulk solution (pH 7.0) of approximately 40% or a depletion of approximately 30% for NH4+ or NO3--grown cells, respectively, at the algal membrane surface of a 5-μm radius cell. Such changes are mainly due to direct H+ uptake or release at the plasmalemma if NO3- or NH4+ is the N source, respectively. Due to these pH changes in the external boundary layer, competition between H+ and metals for uptake is enhanced, for NH4+-grown cells which contributes to a decrease in potential metal uptake. Our model suggests that the uptake of protonated weakly acidic organic acids (HA) is greater in NH4+-grown cells compared to that in NO3--grown cells. The account of chemical reactions in the algal external boundary layer could improve ecological risk assessments for a wide range of contaminants.
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Affiliation(s)
- Michel Lavoie
- Québec-Océan, Takuvik Unité Mixte Internationale (Université Laval-CNRS) and Département de Biologie , Université Laval , Québec , Québec G1V 0A6 , Canada
| | - Jérôme F L Duval
- CNRS, LIEC (Laboratoire Interdisciplinaire des Environnements Continentaux), UMR7360 , Vandoeuvre-lès-Nancy F-54501 , France
- Université de Lorraine, LIEC, UMR7360 , Vandoeuvre-lès-Nancy F-54501 , France
| | - John A Raven
- Division of Plant Science , University of Dundee at the James Hutton Institute , Invergowrie, Dundee DD2 5DA , United Kingdom
- Functional Plant Biology and Climate Change Cluster (C3) , University of Technology Sydney , Ultimo , New South Wales 2007 , Australia
| | - Frédéric Maps
- Québec-Océan, Takuvik Unité Mixte Internationale (Université Laval-CNRS) and Département de Biologie , Université Laval , Québec , Québec G1V 0A6 , Canada
| | - Béchir Béjaoui
- Laboratoire Milieu Marin (LMM) , Institut National des Sciences et Technologies de la Mer , 28, rue du 2 mars 1934 , 2025 , Salammbô , Tunisie
| | - David J Kieber
- Department of Chemistry , State University of New York, College of Environmental Science and Forestry , Syracuse , New York 13210 , United States
| | - Warwick F Vincent
- Québec-Océan, Takuvik Unité Mixte Internationale (Université Laval-CNRS) and Département de Biologie , Université Laval , Québec , Québec G1V 0A6 , Canada
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13
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Yu Z, Wei H, Hao R, Chu H, Zhu Y. Physiological changes in Chlamydomonas reinhardtii after 1000 generations of selection of cadmium exposure at environmentally relevant concentrations. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:923-933. [PMID: 29725674 DOI: 10.1039/c8em00106e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cadmium (Cd) is a nonessential and toxic trace element widely existing in waters through various anthropogenic activities such as mining and waste disposal. The physiological responses of aquatic organisms to long-term Cd exposure at environmentally relevant concentrations are still not well explored. In the present study, two strains of unicellular green algae Chlamydomonas reinhardtii, a walled strain CC125 and a wall-less strain CC406 were selected to investigate the physiological changes of aquatic organisms after long-term Cd exposure at environmentally relevant concentrations (4.92 and 49.2 μg L-1). After about 1000 generations of selection, all of the two strains showed higher intracellular lipid peroxidation and lower photosynthetic activities, and failed to evolve specific adaptation to high levels of Cd (4.92 mg L-1) compared to the control. However, short-term low dose Cd exposure exerted hormetic effects on C. reinhardtii and the hormetic stimulation of growth rate, chlorophyll contents and photochemical activities at the lower concentration of Cd (4.92 μg L-1) groups were more pronounced than those at higher ones (49.2 μg L-1). Taken together, this study confirmed that long-term exposure to Cd at environmentally relevant concentrations which were regarded as nontoxic in acute experiments would produce toxic effects on C. reinhardtii and should be paid more attention.
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Affiliation(s)
- Zhen Yu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
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14
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Rowell JA, Fillion MA, Smith S, Wilkinson KJ. Determination of the speciation and bioavailability of samarium to Chlamydomonas reinhardtii in the presence of natural organic matter. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:1623-1631. [PMID: 29396990 DOI: 10.1002/etc.4106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/22/2017] [Accepted: 01/31/2018] [Indexed: 06/07/2023]
Abstract
As technological interest and environmental emissions of the rare earth elements increase, it is becoming more important to assess their potential environmental impact. Samarium (Sm) is a lanthanide of intermediate molar mass that is used in numerous high-technology applications including wind turbines, solar panels, and electric vehicles. The present study relates the speciation of Sm determined in the presence of natural organic matter (NOM) to its bioavailability to the unicellular green alga Chlamydomonas reinhardtii. The free ion concentration was determined using a cation exchange resin (ion exchange technique) in dynamic mode and compared with thermodynamic modeling. Short-term biouptake experiments were performed in the presence of 4 types of NOM: Suwannee River fulvic acids, Pahokee Peat fulvic acids, Suwannee River humic acids, and a Luther Marsh dissolved organic matter isolate (90-95% humic acids). It was clearly shown that even a small amount of NOM (0.5 mg C L-1 ) resulted in a significant decrease (10 times) in the Sm internalization fluxes. Furthermore, complexation with humic acids (and the corresponding reduction in Sm bioavailability) was stronger than that with fulvic acids. The results showed that the experimentally measured (free) Sm was a better predictor of Sm internalization than either the total concentrations or the free ion concentrations obtained using thermodynamic modeling. Environ Toxicol Chem 2018;37:1623-1631. © 2018 SETAC.
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Affiliation(s)
- Justine-Anne Rowell
- Biophysical Environmental Chemistry Group, Department of Chemistry, University of Montreal, Montreal, Quebec, Canada
| | - Marc-Alexandre Fillion
- Biophysical Environmental Chemistry Group, Department of Chemistry, University of Montreal, Montreal, Quebec, Canada
| | - Scott Smith
- Department of Chemistry, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - Kevin J Wilkinson
- Biophysical Environmental Chemistry Group, Department of Chemistry, University of Montreal, Montreal, Quebec, Canada
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15
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Pérez E, Hoang TC. Chronic toxicity of binary-metal mixtures of cadmium and zinc to Daphnia magna. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:2739-2749. [PMID: 28430390 DOI: 10.1002/etc.3830] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/09/2017] [Accepted: 04/19/2017] [Indexed: 06/07/2023]
Abstract
The present study characterized the chronic effect of binary-metal mixtures of cadmium (Cd) and zinc (Zn) on Daphnia magna. The titration design was chosen to characterize the 21-d chronic effects of the binary-metal mixtures on survival, growth, reproduction, and metal accumulation in D. magna. Using this design, increasing concentrations of Zn (10, 20, 40, 80, 120, 160, and 200 μg/L) were titrated against a constant concentration of 1.5 μg/L Cd. The results demonstrated that Cd was highly toxic to D. magna. In a mixture with Cd and Zn, sublethal concentrations of 10 and 20 μg/L Zn were insufficient to protect D. magna from chronic Cd toxicity, whereas mixtures containing 40, 80, and 120 μg/L Zn provided strong protective effects to D. magna at all endpoints and resulted in less-than-additive effects. At higher Zn concentrations, such as 160 and 200 μg/L, Zn appeared to contribute to the toxicity. The less-than-additive effects observed in the Cd-Zn mixture can be explained by the decrease in body Cd concentration when the Zn concentration was increased in the exposure media. Embryos analyzed for morphological alterations in the Cd-Zn mixtures demonstrated severe developmental defects. The effect of Cd on undeveloped embryos while both Zn and Cd are present in the organisms raises a question of whether the competitive binding mechanism of Zn and Cd is still happening at the cellular level in the organisms. The results of the present study are useful for development of the biotic ligand model and environmental quality guidelines for metal mixtures. Environ Toxicol Chem 2017;36:2739-2749. © 2017 SETAC.
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Affiliation(s)
- Edgar Pérez
- Institute of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois, USA
| | - Tham C Hoang
- Institute of Environmental Sustainability, Loyola University Chicago, Chicago, Illinois, USA
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16
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Wang Y, Zhang C, Zheng Y, Ge Y. Bioaccumulation kinetics of arsenite and arsenate in Dunaliella salina under different phosphate regimes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:21213-21221. [PMID: 28733823 DOI: 10.1007/s11356-017-9758-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 07/11/2017] [Indexed: 05/05/2023]
Abstract
Dunaliella salina is a potential candidate for the phycoremediation of saline water contaminated with arsenic (As) due to its strong tolerance of salt and this toxic metalloid. However, the efficiency of As removal by this microalga varies under different phosphate regimes and the underlying mechanisms remain unresolved. Therefore, more detailed studies are needed to optimize As remediation using D. salina. Here, we investigated the dynamic processes of arsenite (As(III)) and arsenate (As(V)) uptake, transformation, and excretion by D. salina under phosphate-deficient (-P) and phosphate-enriched (+P) conditions through short-term and long-term uptake experiments. In the short-term uptake experiment, the absorption of As(III) or As(V) by D. salina was significantly suppressed by an increased phosphate supply. The V max values for As(III) and As(V) decreased by 2- and 2.5-fold, respectively, under +P conditions, although the Michaelis constants (K m ) were similar irrespective of the phosphate supply. Long-term uptake experiments also revealed enhanced As(III)/As(V) absorption and efflux rates and As(V) reduction by D. salina under -P conditions. This study quantified the kinetic processes of As metabolism in D. salina. More importantly, the results imply that the optimal As remediation by this microalga may be achieved by regulating the phosphate level in the culture.
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Affiliation(s)
- Ya Wang
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
- Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Chunhua Zhang
- Demonstration Laboratory of Element and Life Science Research, Laboratory Centre of Life Science, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanheng Zheng
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ying Ge
- Jiangsu Provincial Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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17
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Jakob L, Bedulina DS, Axenov-Gribanov DV, Ginzburg M, Shatilina ZM, Lubyaga YA, Madyarova EV, Gurkov AN, Timofeyev MA, Pörtner HO, Sartoris FJ, Altenburger R, Luckenbach T. Uptake Kinetics and Subcellular Compartmentalization Explain Lethal but Not Sublethal Effects of Cadmium in Two Closely Related Amphipod Species. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7208-7218. [PMID: 28493692 DOI: 10.1021/acs.est.6b06613] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Eulimnogammarus cyaneus and Eulimnogammarus verrucosus, closely related amphipod species endemic to Lake Baikal, differ with respect to body size (10- to 50-fold lower fresh weights of E. cyaneus) and cellular stress response (CSR) capacity, potentially causing species-related differences in uptake, internal sequestration, and toxic sensitivity to waterborne cadmium (Cd). We found that, compared to E. verrucosus, Cd uptake rates, related to a given exposure concentration, were higher, and lethal concentrations (50%; LC50) were 2.3-fold lower in E. cyaneus (4 weeks exposure; 6 °C). Upon exposures to species-specific subacutely toxic Cd concentrations (nominal LC1; E. cyaneus: 18 nM (2.0 μg L-1); E. verrucosus: 115 nM (12.9 μg L-1); 4 weeks exposure; 6 °C), Cd amounts in metal sensitive tissue fractions (MSF), in relation to fresh weight, were similar in both species (E. cyaneus: 0.25 ± 0.06 μg g-1; E. verrucosus: 0.26 ± 0.07 μg g-1), whereas relative Cd amounts in the biologically detoxified heat stable protein fraction were 35% higher in E. cyaneus. Despite different potencies in detoxifying Cd, body size appears to mainly explain species-related differences in Cd uptake and sensitivities. When exposed to Cd at LC1 over 4 weeks, only E. verrucosus continuously showed 15-36% reduced oxygen consumption rates indicating metabolic depression and pointing to particular sensitivity of E. verrucosus to persisting low-level toxicant pressure.
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Affiliation(s)
- Lena Jakob
- Department of Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research , Am Handelshafen 12, 27570 Bremerhaven, Germany
- Faculty of Biology and Chemistry, University of Bremen , Leobener Straße, 28359 Bremen, Germany
| | - Daria S Bedulina
- Institute of Biology, Irkutsk State University , Karl Marx street 1, 664003 Irkutsk, Russia
| | | | - Michael Ginzburg
- Department of Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research , Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Zhanna M Shatilina
- Institute of Biology, Irkutsk State University , Karl Marx street 1, 664003 Irkutsk, Russia
| | - Yulia A Lubyaga
- Institute of Biology, Irkutsk State University , Karl Marx street 1, 664003 Irkutsk, Russia
| | - Ekaterina V Madyarova
- Institute of Biology, Irkutsk State University , Karl Marx street 1, 664003 Irkutsk, Russia
| | - Anton N Gurkov
- Institute of Biology, Irkutsk State University , Karl Marx street 1, 664003 Irkutsk, Russia
| | - Maxim A Timofeyev
- Institute of Biology, Irkutsk State University , Karl Marx street 1, 664003 Irkutsk, Russia
| | - Hans-O Pörtner
- Department of Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research , Am Handelshafen 12, 27570 Bremerhaven, Germany
- Faculty of Biology and Chemistry, University of Bremen , Leobener Straße, 28359 Bremen, Germany
| | - Franz J Sartoris
- Department of Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research , Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Rolf Altenburger
- Department of Bioanalytical Ecotoxicology, UFZ - Helmholtz Centre for Environmental Research , Permoserstraße 15, 04318 Leipzig, Germany
| | - Till Luckenbach
- Department of Bioanalytical Ecotoxicology, UFZ - Helmholtz Centre for Environmental Research , Permoserstraße 15, 04318 Leipzig, Germany
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18
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Tan QG, Yang G, Wilkinson KJ. Biotic ligand model explains the effects of competition but not complexation for Sm biouptake by Chlamydomonas reinhardtii. CHEMOSPHERE 2017; 168:426-434. [PMID: 27810543 DOI: 10.1016/j.chemosphere.2016.10.051] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/01/2016] [Accepted: 10/13/2016] [Indexed: 06/06/2023]
Abstract
The applicability of the biotic ligand model (BLM) was tested with respect to the biouptake of the lanthanide Sm by the freshwater green alga, Chlamydomonas reinhardtii. In the absence of organic ligands, Sm uptake was well described by the Michaelis-Menten equation, consistent with the BLM assumption of single transporter, with the maximum influx rate (Jmax) of 1.5 × 10-14 mol cm-2 s-1 and a binding constant (KSm) of 107.0 M-1. The addition of organic ligands (i.e., malic acid, diglycolic acid and citric acid) decreased Sm influx rates, however, the decreases were much less than that predicted by the BLM, possibly due to the direct contribution of the Sm complexes. Competition effects of two major cations (Ca2+ and Mg2+) and three lanthanide cations (La3+, Ce3+ and Eu3+) were successfully modeled by the BLM, with binding constants corresponding to KCa = 104.0 M-1, KMg = 102.7 M-1, KLa = 106.8 M-1, KCe = 106.9 M-1 and KEu = 107.0 M-1. The binding constants and Jmax were very similar among the four investigated lanthanides and varied progressively with atomic number; therefore, the results obtained in the present study can probably be extrapolated to other rare earth metals.
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Affiliation(s)
- Qiao-Guo Tan
- College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China; Department of Chemistry, University of Montreal, P.O. Box 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7, Canada
| | - Guang Yang
- Department of Chemistry, University of Montreal, P.O. Box 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7, Canada; College of Urban Construction, Hebei University of Engineering, Handan, Hebei, China
| | - Kevin J Wilkinson
- Department of Chemistry, University of Montreal, P.O. Box 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7, Canada.
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Nagai T, De Schamphelaere KAC. The effect of binary mixtures of zinc, copper, cadmium, and nickel on the growth of the freshwater diatom Navicula pelliculosa and comparison with mixture toxicity model predictions. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2016; 35:2765-2773. [PMID: 27043471 DOI: 10.1002/etc.3445] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/03/2015] [Accepted: 03/30/2016] [Indexed: 06/05/2023]
Abstract
The authors investigated the effect of binary mixtures of zinc (Zn), copper (Cu), cadmium (Cd), and nickel (Ni) on the growth of a freshwater diatom, Navicula pelliculosa. A 7 × 7 full factorial experimental design (49 combinations in total) was used to test each binary metal mixture. A 3-d fluorescence microplate toxicity assay was used to test each combination. Mixture effects were predicted by concentration addition and independent action models based on a single-metal concentration-response relationship between the relative growth rate and the calculated free metal ion activity. Although the concentration addition model predicted the observed mixture toxicity significantly better than the independent action model for the Zn-Cu mixture, the independent action model predicted the observed mixture toxicity significantly better than the concentration addition model for the Cd-Zn, Cd-Ni, and Cd-Cu mixtures. For the Zn-Ni and Cu-Ni mixtures, it was unclear which of the 2 models was better. Statistical analysis concerning antagonistic/synergistic interactions showed that the concentration addition model is generally conservative (with the Zn-Ni mixture being the sole exception), indicating that the concentration addition model would be useful as a method for a conservative first-tier screening-level risk analysis of metal mixtures. Environ Toxicol Chem 2016;35:2765-2773. © 2016 SETAC.
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Affiliation(s)
- Takashi Nagai
- National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki, Japan.
- Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University, Ghent, Belgium.
| | - Karel A C De Schamphelaere
- Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University, Ghent, Belgium
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Chen WY, Chen TY, Hsieh NH, Ju YT. Site-specific water quality criteria for lethal/sublethal protection of freshwater fish exposed to zinc in southern Taiwan. CHEMOSPHERE 2016; 159:412-419. [PMID: 27337432 DOI: 10.1016/j.chemosphere.2016.06.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/18/2016] [Accepted: 06/06/2016] [Indexed: 06/06/2023]
Abstract
There were considerable concerns about the zinc (Zn) pollution caused by electroplating, chemical, and computer-related high-tech industrial discharges in Kaohsiung Rivers situated at south Taiwan. There is, however, a lack of site-specific water chemistry based toxicity assessment and little is known about the sublethal toxicity on freshwater fish. This study proposes an integrated framework to link experimental and mechanistic model-based data analysis of lethal and sublethal Zn toxicities for grass carp (Ctenopharyn odon idellus) populations for providing the site-specific Zn water quality threshold in Kaohsiung Rivers. A biotic ligand model (BLM) that relates toxicity impairment of physiological active sites impacted by Zn species was used to elucidate the site-specific water chemistry affecting the bioavailability and biological response of grass carp exposed to Zn. Results indicated that 96-h LC50 for mortality and 28-d EC50 for growth inhibition were 474.7 ± 1.3 (mean ± SE) and 149 ± 23.5 μg L(-1), respectively. Here the BLM-based predicted steady-state LC50s for mortality were 2110.7, 818.2, 1303.6, 563.3, and 497.1 μg L(-1), whereas measured steady-state EC50s for growth inhibition were 726.8, 326.2, 373.4, 193.9, and 170.5 μg L(-1) for the Agongdian, Houling, Love, Fengshan, and Gaoping Rivers, respectively. A positive correlation between Mg(2+) and EC50 values were found in both acute (r = 0.94, p < 0.01) and chronic (r = 0.97, p < 0.01) Zn exposures. This study suggests that the use of site-specific water chemistry data and ecophysiological traits would enhance the predictive capacities to assess the potential effect of metal toxicity posed to aquatic organisms.
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Affiliation(s)
- Wei-Yu Chen
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, ROC.
| | - Tzu-Yin Chen
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, ROC
| | - Nan-Hung Hsieh
- Institute of Labor, Occupational Safety and Health, Ministry of Labor, New Taipei City 22143, Taiwan, ROC
| | - Yi-Ting Ju
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, ROC
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Mera R, Torres E, Abalde J. Isobolographic analysis of the interaction between cadmium (II) and sodium sulphate: toxicological consequences. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:2264-2278. [PMID: 26658783 DOI: 10.1007/s11356-015-5909-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/01/2015] [Indexed: 06/05/2023]
Abstract
Sulphate is an essential nutrient for autotrophic organisms and has been shown to have important implications in certain processes of tolerance to cadmium toxicity. Sodium sulphate is the main salt of sulphate in the natural environments. The concentration of this salt is increasing in the aquatic environments due to environmental pollution. The aim of this study was to investigate, using an analysis of isobolograms, the type and the degree of the interaction between Cd(II) and sodium sulphate in the freshwater microalga Chlamydomonas moewusii. Two blocks of experiments were performed, one at sub-optimal sodium sulphate concentrations (<14.2 mg/L) and the other at supra-optimal concentrations (>14.2 mg/L). Three fixed ratios (2:1, 1:1, and 1:2) of the individual EC50 for cadmium and sodium sulphate were used within each block. The isobolographic analysis of interaction at sub-optimal concentrations showed a stronger antagonistic effect with values of interaction index (γ) between 1.46 and 3.4. However, the isobologram with sodium sulphate at supra-optimal concentrations revealed a slight but significant synergistic effect between both chemicals with an interaction index between 0.54 and 0.64. This synergic effect resulted in the potentiation of the toxic effects of cadmium, synergy that was related to the increase of the ionic strength and of two species of cadmium, CdSO4 (aq), and Cd(SO4)2(2-) , in the medium. Results of the current study suggest that sodium sulphate is able to perform a dual antagonist/synergist effect on cadmium toxicity. This role was concentration dependent.
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Affiliation(s)
- Roi Mera
- Laboratorio de Microbiología, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidade da Coruña, Campus da Zapateira s/n, 15071, La Coruña, Spain
| | - Enrique Torres
- Laboratorio de Microbiología, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidade da Coruña, Campus da Zapateira s/n, 15071, La Coruña, Spain.
| | - Julio Abalde
- Laboratorio de Microbiología, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidade da Coruña, Campus da Zapateira s/n, 15071, La Coruña, Spain
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22
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Paquet N, Lavoie M, Maloney F, Duval JFL, Campbell PGC, Fortin C. Cadmium accumulation and toxicity in the unicellular alga Pseudokirchneriella subcapitata: Influence of metal-binding exudates and exposure time. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2015; 34:1524-32. [PMID: 25662885 DOI: 10.1002/etc.2927] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/10/2014] [Accepted: 02/02/2015] [Indexed: 05/09/2023]
Abstract
Predicting metal availability and toxicity for chronic (several hours or days) metal exposure scenarios, even for unicellular algae, is a major challenge to existing toxicity models. This is because several factors affecting metal uptake and toxicity, such as the release of metal-binding exudates, changes in the kinetics of metal uptake and toxicity over time, and algal physiological acclimation to internalized metals, are still poorly understood. The present study assessed the influence of these factors on Cd uptake and toxicity in laboratory batch cultures of the freshwater alga Pseudokirchneriella subcapitata. To do so, changes in the free Cd(2+) concentrations caused by the release of metal-binding algal exudates were monitored, (109)Cd accumulation in algal cells was measured, and Cd-induced inhibition of algal growth as a function of exposure time (from 12 h to 96 h) was followed. Results indicate that metal-binding exudates may decrease the proportion of the free Cd(2+) ion in solution up to 2-fold, a decrease that affects Cd uptake and toxicity. Pseudokirchneriella subcapitata has the capacity to decrease net Cd uptake rate on short time scales (<24 h), but this reduction in the Cd uptake rate disappeared after 24 h, and Cd toxicity occurred at relatively high Cd concentrations in solution. These data illustrate some of the pitfalls of standard algal toxicity assays, which were designed for acute exposures, and suggest how robust chronic bioassays might be developed.
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Affiliation(s)
- Nathalie Paquet
- Institut national de la recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
- Centre d'expertise en analyse environnementale du Québec, Ministère du développement durable, de l'Environnement et de la Lutte contre les changements climatiques, Québec, Québec, Canada
| | - Michel Lavoie
- Institut national de la recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
- Québec-Océan and Takuvik Joint Université Laval/CNRS Research Units, Département de Biologie, Université Laval, Québec, Québec, Canada
| | - Frédéric Maloney
- Institut national de la recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
- Administration portuaire de Québec, Québec, Québec, Canada
| | - Jérôme F L Duval
- Laboratoire interdisciplinaire des Environnements Continentaux (LIEC, UMR7360), CNRS-Université de Lorraine, Vandoeuvre-lès-Nancy, F-54501, France
| | - Peter G C Campbell
- Institut national de la recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
| | - Claude Fortin
- Institut national de la recherche scientifique, Centre Eau Terre Environnement (INRS-ETE), Québec, Québec, Canada
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Duval JFL, Paquet N, Lavoie M, Fortin C. Dynamics of Metal Partitioning at the Cell-Solution Interface: Implications for Toxicity Assessment under Growth-Inhibiting Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:6625-6636. [PMID: 25945520 DOI: 10.1021/acs.est.5b00594] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Metal toxicity toward microorganisms is usually evaluated by determining growth inhibition. To achieve a mechanistic interpretation of such toxic effects, the intricate coupling between cell growth kinetics and metal partitioning dynamics at the cell-solution interface over time must be considered on a quantitative level. A formalism is elaborated to evaluate cell-surface-bound, internalized, and extracellular metal fractions in the limit where metal uptake kinetics is controlled by internalization under noncomplexing medium conditions. Cell growth kinetics is tackled using the continuous logistic equation modified to include growth inhibition by metal accumulation to intracellular or cell surface sites. The theory further includes metal-proton competition for adsorption at cell-surface binding sites, as well as possible variation of cell size during exposure to metal ions. The formalism elucidates the dramatic impacts of initial cell concentration on metal bioavailability and toxicity over time, in agreement with reported algae bioassays. It further highlights that appropriate definition of toxicity endpoints requires careful inspection of the ratio between exposure time scale and time scale of metal depletion from bulk solution. The latter depends on metal internalization-excretion rate constants, microorganism growth, and the extent of metal adsorption on nonspecific, transporter, and growth inhibitory sites. As an application of the theory, Cd toxicity in the algae Pseudokirchneriella subcapitata is interpreted from constrained modeling of cell growth kinetics and of interfacial Cd-partitioning dynamics measured under various exposure conditions.
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Affiliation(s)
- Jérôme F L Duval
- †Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS, UMR7360, Vandoeuvre-lès-Nancy, F-54501, France
- ‡Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Université de Lorraine, UMR7360, Vandoeuvre-lès-Nancy, F-54501, France
| | - Nathalie Paquet
- §Centre Eau Terre Environnement (INRS-ETE), Institut National de la Recherche Scientifique, 490 de la Couronne, Québec G1K 9A9, Canada
| | - Michel Lavoie
- §Centre Eau Terre Environnement (INRS-ETE), Institut National de la Recherche Scientifique, 490 de la Couronne, Québec G1K 9A9, Canada
| | - Claude Fortin
- §Centre Eau Terre Environnement (INRS-ETE), Institut National de la Recherche Scientifique, 490 de la Couronne, Québec G1K 9A9, Canada
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24
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Ma J, Cai H, He C, Zhang W, Wang L. A hemicellulose-bound form of silicon inhibits cadmium ion uptake in rice (Oryza sativa) cells. THE NEW PHYTOLOGIST 2015; 206:1063-1074. [PMID: 25645894 DOI: 10.1111/nph.13276] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 12/12/2014] [Indexed: 05/06/2023]
Abstract
Silicon (Si) alleviates cadmium (Cd) toxicity in rice (Oryza sativa). However, the chemical mechanisms at the single-cell level are poorly understood. Here, a suspension of rice cells exposed to Cd and/or Si treatments was investigated using a combination of plant cell nutritional, molecular biological, and physical techniques including in situ noninvasive microtest technology (NMT), polymerase chain reaction (PCR), inductively coupled plasma mass spectroscopy (ICP-MS), and atomic force microscopy (AFM) in Kelvin probe mode (KPFM). We found that Si-accumulating cells had a significantly reduced net Cd(2+) influx, compared with that in Si-limited cells. PCR analyses of the expression levels of Cd and Si transporters in rice cells showed that, when the Si concentration in the medium was increased, expression of the Si transporter gene Low silicon rice 1 (Lsi1) was up-regulated, whereas expression of the gene encoding the transporter involved in the transport of Cd, Natural resistance-associated macrophage protein 5 (Nramp5), was down-regulated. ICP-MS results revealed that 64% of the total Si in the cell walls was bound to hemicellulose constituents following the fractionation of the cell walls, and consequently inhibited Cd uptake. Furthermore, AFM in KPFM demonstrated that the heterogeneity of the wall surface potential was higher in cells cultured in the presence of Si than in those cultured in its absence, and was homogenized after the addition of Cd. These results suggest that a hemicellulose-bound form of Si with net negative charges is responsible for inhibition of Cd uptake in rice cells by a mechanism of [Si-hemicellulose matrix]Cd complexation and subsequent co-deposition.
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Affiliation(s)
- Jie Ma
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hongmei Cai
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Congwu He
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
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25
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Meyer JS, Ranville JF, Pontasch M, Gorsuch JW, Adams WJ. Acute toxicity of binary and ternary mixtures of Cd, Cu, and Zn to Daphnia magna. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2015; 34:799-808. [PMID: 25336231 DOI: 10.1002/etc.2787] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/17/2014] [Accepted: 10/19/2014] [Indexed: 06/04/2023]
Abstract
Standard static-exposure acute lethality tests were conducted with Daphnia magna neonates exposed to binary or ternary mixtures of Cd, Cu, and Zn in moderately hard reconstituted water that contained 3 mg dissolved organic carbon/L added as Suwannee River fulvic acid. These experiments were conducted to test for additive toxicity (i.e., the response to the mixture can be predicted by combining the responses obtained in single-metal toxicity tests) or nonadditive toxicity (i.e., the response is less than or greater than additive). Based on total metal concentrations (>90% dissolved) the toxicity of the tested metal mixtures could be categorized into all 3 possible additivity categories: less-than-additive toxicity (e.g., Cd-Zn and Cd-Cu-Zn mixtures and Cd-Cu mixtures when Cu was titrated into Cd-containing waters), additive toxicity (e.g., some Cu-Zn mixtures), or more-than-additive toxicity (some Cu-Zn mixtures and Cd-Cu mixtures when Cd was titrated into Cu-containing waters). Exposing the organisms to a range of sublethal to supralethal concentrations of the titrated metal was especially helpful in identifying nonadditive interactions. Geochemical processes (e.g., metal-metal competition for binding to dissolved organic matter and/or the biotic ligand, and possibly supersaturation of exposure waters with the metals in some high-concentration exposures) can explain much of the observed metal-metal interactions. Therefore, bioavailability models that incorporate those geochemical (and possibly some physiological) processes might be able to predict metal mixture toxicity accurately.
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Affiliation(s)
- Joseph S Meyer
- ARCADIS U.S., Lakewood, Colorado, USA; Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado, USA
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26
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Zhao CM, Wilkinson KJ. Biotic ligand model does not predict the bioavailability of rare Earth elements in the presence of organic ligands. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2207-14. [PMID: 25611881 DOI: 10.1021/es505443s] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Due to their distinct physicochemical properties, rare earth elements (REEs) are critical to high-tech and clean-energy industries; however, their bioavailability is still largely unexplored. In this paper, the bioavailability of several REEs has been carefully examined for the freshwater alga, Chlamydomonas reinhardtii. In the presence of organic ligands (L), the biouptake of REEs was much higher than that predicted by the biotic ligand model (BLM). Enhancement of the biouptake flux was observed for six ligands (metal = thulium) and six REEs (ligand = citric acid), indicating that this could be a common feature for these metals. In order to explore the mechanism for the enhanced uptake, Tm internalization was carefully evaluated. The Tm internalization flux (Jint) followed first-order (Michaelis-Menten) kinetics with a calculated maximum internalization flux (Jmax) of (1.1 ± 0.08) × 10(-14) mol · cm(-2) · s(-1) and an affinity constant for the reaction of the metal with the transport sites (KTm-R) of 10(7.1) M(-1). In the presence of citric acid, malic acid, or NTA, the Jint for Tm was more than 1 order of magnitude higher than that predicted by the BLM when algae were exposed to a constant 10(-9) M Tm(3+). The bioavailability of the metal complexes could not be explained by a piggyback internalization (through an anion channel) or the contribution of labile complexes. The enhanced biouptake was attributed to the formation of a ternary Tm complex {L-Tm-R} at the metal transport site. In the natural environment where organic ligands are ubiquitous, classic models are unlikely to predict the bioavailability of REEs to aquatic organisms.
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Affiliation(s)
- Chun-Mei Zhao
- Biophysical Environmental Chemistry Group, Department of Chemistry, University of Montreal , C.P. 6128 Succursale Centre-Ville, Montreal, Quebec H3C 3J7, Canada
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27
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Ardestani MM, van Straalen NM, van Gestel CAM. The relationship between metal toxicity and biotic ligand binding affinities in aquatic and soil organisms: a review. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 195:133-47. [PMID: 25217851 DOI: 10.1016/j.envpol.2014.08.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 08/14/2014] [Accepted: 08/18/2014] [Indexed: 05/04/2023]
Abstract
The biotic ligand model (BLM) is a theoretical, potentially mechanistic approach to assess metal bioavailability in soil and aquatic systems. In a BLM, toxicity is linked to the fraction of biotic ligand occupied, which in turn, depends on the various components of the solution, including activity of the metal. Bioavailability is a key factor in determining toxicity and uptake of metals in organisms. In this study, the present status of BLM development for soil and aquatic organisms is summarized. For all species and all metals, toxicity was correlated with the conditional biotic ligand binding constants. For almost all organisms, values for Ag, Cu, and Cd were higher than those for Zn and Ni. The constants derived for aquatic systems seem to be equally valid for soil organisms, but in the case of soils, bioavailability from the soil solution is greatly influenced by the presence of the soil solid phase.
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Affiliation(s)
- Masoud M Ardestani
- Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
| | - Nico M van Straalen
- Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
| | - Cornelis A M van Gestel
- Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
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28
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Yang G, Tan QG, Zhu L, Wilkinson KJ. The role of complexation and competition in the biouptake of europium by a unicellular alga. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2014; 33:2609-2615. [PMID: 25132226 DOI: 10.1002/etc.2722] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 05/18/2014] [Accepted: 08/07/2014] [Indexed: 06/03/2023]
Abstract
Short-term (60 min) europium (Eu) biouptake fluxes by the freshwater green alga Chlamydomonas reinhardtii were investigated in the presence and absence of ligands (e.g., malic acid and citric acid) and a second rare earth metal, samarium (Sm). Data were interpreted in the context of the biotic ligand model, which uses experimentally determined stability constants to take into account the competition and complexation of the metal of interest. In the absence of ligands or competitors, Eu biouptake was well described by a Michaelis-Menten equation with the maximal uptake flux (Jmax ) and Michaelis-Menten constant (Km ) of Jmax = 1.7 × 10(-14) mol cm(-2) s(-1) and Km = 10(-7.0) M (corresponding to an affinity constant of 10(7.0) M(-1) ). Biouptake of Eu (or Sm) decreased as the concentration of a competing rare earth element (i.e., Sm or Eu) increased, as predicted by the biotic ligand model. On the other hand, when hydrophilic complexes were formed with citric and malic acid, Eu biouptake was much greater than predicted on the basis of free ion concentrations alone. Overall, the results showed that for C. reinhardtii the rare earth elements were likely to share a common biouptake pathway; biouptake of one rare earth element was reduced when another was present, and rare earth element complexes were bioavailable.
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Affiliation(s)
- Guang Yang
- Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin, China; Department of Chemistry, Biophysical Environmental Chemistry Group, University of Montreal, Montreal, Quebec, Canada
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29
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Lavoie M, Campbell PGC, Fortin C. Predicting cadmium accumulation and toxicity in a green alga in the presence of varying essential element concentrations using a biotic ligand model. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:1222-1229. [PMID: 24341312 DOI: 10.1021/es402630z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This study refines the Biotic Ligand Model (BLM) approach by integrating the modulating effects of various essential elements on cadmium (Cd) uptake kinetics in the freshwater alga Chlamydomonas reinhardtii. The algae were first acclimated to a low (LM) or high trace metal (HM) medium as well as to low or high free Cd(2+) and Co(2+) concentrations. The short-term Cd transport capacity and affinity were then quantified in exposure media in which essential trace metals and calcium concentrations were manipulated. The results show that after acclimation to the LM medium, exposure to high free Ca(2+) decreases the capacity of the Cd transport system. Also, acclimation to high (10(-9) M free Co(2+)) or low (10(-11) M free Co(2+)) did not significantly affect Cd uptake rates. When all essential trace metals were simultaneously increased in the acclimation (and exposure) medium, the capacity of the transport system decreased by ∼ 60%, a decrease close to that due to high [Zn(2+)] alone, suggesting that Zn is the main trace metal modulator of the Cd transporter capacity. Changes in Cd toxicity (growth inhibition) in the presence of different essential trace metal concentrations were strongly related to the steady-state concentration of intracellular cadmium, regardless of the cell's nutritional state. Our BLM incorporating the physiological effects of Ca(2+) and other trace metals predicts steady-state Cd accumulation in the presence of varying concentrations of essential elements at 7 nM free Cd(2+), but predictions over a wide range of free [Cd(2+)] proved to be more difficult.
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Affiliation(s)
- Michel Lavoie
- Institut National de la Recherche Scientifique, Centre Eau Terre Environnement (INRS-ETE) , 490 de la Couronne, Québec, G1K 9A9 Québec, Canada
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30
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Lead (Pb) and copper (Cu) share a common uptake transporter in the unicellular alga Chlamydomonas reinhardtii. Biometals 2014; 27:173-81. [DOI: 10.1007/s10534-013-9699-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 12/27/2013] [Indexed: 12/29/2022]
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31
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Ou-Yang HL, Kong XZ, Lavoie M, He W, Qin N, He QS, Yang B, Wang R, Xu FL. Photosynthetic and cellular toxicity of cadmium in Chlorella vulgaris. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:2762-2770. [PMID: 23966280 DOI: 10.1002/etc.2362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 01/18/2013] [Accepted: 08/14/2013] [Indexed: 06/02/2023]
Abstract
The toxic effects of cadmium (Cd) on the green alga Chlorella vulgaris were investigated by following the response to Cd of various toxicity endpoints (cell growth, cell size, photochemical efficiency of PSII in the light or Φ(PSII), maximal photochemical efficiency or Fv/Fm, chlorophyll a fluorescence, esterase activity, and cell viability). These toxicity endpoints were studied in laboratory batch cultures of C. vulgaris over a long-term 96-h exposure to different Cd concentrations using flow cytometry and pulse amplitude modulated fluorometry. The sequence of sensitivity of these toxicity endpoints was: cell yield >> Φ(PSII) ≈ esterase activity > Fv/Fm > chlorophyll a fluorescence ≈ cell viability. It is shown that cell apoptosis or cell death only accounted for a minor part of the reduction in cell yield even at very high algistatic free Cd²⁺ concentrations, and other mechanisms such as blocked cell divisions are major contributors to cell yield inhibition. Furthermore, cadmium may affect both the electron donors and acceptors of the electron transport chain at high free Cd²⁺ concentration. Finally, the resistance of cells to cell death was size-dependent; medium-sized cells had the highest toxicity threshold. The present study brings new insights into the toxicity mechanisms of Cd in C. vulgaris and provides a detailed comparison of the sensitivity of various Cd toxicity endpoints.
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Affiliation(s)
- Hui-Ling Ou-Yang
- MOE Laboratory for Earth Surface Process, College of Urban & Environmental Sciences, Peking University, Beijing, China
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32
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Gunawan C, Sirimanoonphan A, Teoh WY, Marquis CP, Amal R. Submicron and nano formulations of titanium dioxide and zinc oxide stimulate unique cellular toxicological responses in the green microalga Chlamydomonas reinhardtii. JOURNAL OF HAZARDOUS MATERIALS 2013; 260:984-992. [PMID: 23892165 DOI: 10.1016/j.jhazmat.2013.06.067] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 06/14/2013] [Accepted: 06/26/2013] [Indexed: 06/02/2023]
Abstract
The work investigates the eco-cytoxicity of submicron and nano TiO₂ and ZnO, arising from the unique interactions of freshwater microalga Chlamydomonas reinhardtii to soluble and undissolved components of the metal oxides. In a freshwater medium, submicron and nano TiO₂ exist as suspended aggregates with no-observable leaching. Submicron and nano ZnO undergo comparable concentration-dependent fractional leaching, and exist as dissolved zinc and aggregates of undissolved ZnO. Cellular internalisation of solid TiO₂ stimulates cellular ROS generation as an early stress response. The cellular redox imbalance was observed for both submicron and nano TiO₂ exposure, despite exhibiting benign effects on the alga proliferation (8-day EC50>100 mg TiO₂/L). Parallel exposure of C. reinhardtii to submicron and nano ZnO saw cellular uptake of both the leached zinc and solid ZnO and resulting in inhibition of the alga growth (8-day EC50≥0.01 mg ZnO/L). Despite the sensitivity, no zinc-induced cellular ROS generation was detected, even at 100 mg ZnO/L exposure. Taken together, the observations confront the generally accepted paradigm of cellular oxidative stress-mediated cytotoxicity of particles. The knowledge of speciation of particles and the corresponding stimulation of unique cellular responses and cytotoxicity is vital for assessment of the environmental implications of these materials.
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Affiliation(s)
- Cindy Gunawan
- ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, Australia.
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33
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Crémazy A, Campbell PGC, Fortin C. The biotic ligand model can successfully predict the uptake of a trivalent ion by a unicellular alga below pH 6.50 but not above: possible role of hydroxo-species. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:2408-2415. [PMID: 23360212 DOI: 10.1021/es3038388] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In many reported cases, the biotic ligand model (BLM) has been shown to predict the bioavailability of divalent metals toward aquatic biota successfully. However, studies on the bioavailability of nonessential trivalent metals, including aluminum (Al), are relatively scarce. In the present study, short-term scandium (Sc) internalization fluxes (Jint) were measured in Chlamydomonas reinhardtii in order to explore the applicability of the BLM to trivalent metals. Scandium was selected for its chemical similarities with Al and for its convenient radio-isotope (Sc-46). Apparent affinity constants of Sc(3+) with membrane transport sites (KSc-Rcell app) were surprisingly high, ranging from 10(8.08) M(-1) to 10(13.95) M(-1) over the pH range from 4.50 to 7.90. The competition of H(+) for binding with Sc(3+) transport sites explained this trend within the pH range of 4.50 to 6.00, but not from pH 6.50-7.90. In this latter pH range, predicted fluxes were smaller than observed fluxes and this divergence increased with pH, from a factor of 4 to approximately 1000. Above pH 6.50, the calculated supply of Sc(3+) to the biointerface by physical diffusion of the free Sc(3+) ion and by the dissociation of its hydroxo-complexes (ScOH(2+), Sc(OH)2(+) and Sc(OH)3) was insufficient to support the high observed internalization fluxes. We speculate that this failure of the BLM could be due to the transmembrane transport of undissociated Sc hydroxo-complexes. Scandium uptake could be modeled reasonably well using a simple semiempirical equation considering equal contributions from Sc(3+), ScOH(2+), Sc(OH)2(+), and Sc(OH)3 and no H(+) competition. Our work highlights the importance of studying the possible role of hydroxo-species in trace metal uptake.
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Affiliation(s)
- Anne Crémazy
- Institut national de la recherche scientifique, Centre Eau Terre Environnement (INRS-ETE) , 490 de la Couronne, G1K 9A9, Québec, Canada
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