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Díaz S, Aguilera Á, de Figueras CG, de Francisco P, Olsson S, Puente-Sánchez F, González-Pastor JE. Heterologous Expression of the Phytochelatin Synthase CaPCS2 from Chlamydomonas acidophila and Its Effect on Different Stress Factors in Escherichia coli. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19137692. [PMID: 35805349 PMCID: PMC9265389 DOI: 10.3390/ijerph19137692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/19/2022] [Accepted: 06/21/2022] [Indexed: 11/19/2022]
Abstract
Phytochelatins (PCs) are cysteine-rich small peptides, enzymatically synthesized from reduced glutathione (GSH) by cytosolic enzyme phytochelatin synthase (PCS). The open reading frame (ORF) of the phytochelatin synthase CaPCS2 gene from the microalgae Chlamydomonas acidophila was heterologously expressed in Escherichia coli strain DH5α, to analyze its role in protection against various abiotic agents that cause cellular stress. The transformed E. coli strain showed increased tolerance to exposure to different heavy metals (HMs) and arsenic (As), as well as to acidic pH and exposure to UVB, salt, or perchlorate. In addition to metal detoxification activity, new functions have also been reported for PCS and PCs. According to the results obtained in this work, the heterologous expression of CaPCS2 in E. coli provides protection against oxidative stress produced by metals and exposure to different ROS-inducing agents. However, the function of this PCS is not related to HM bioaccumulation.
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Affiliation(s)
- Silvia Díaz
- Department of Genetics, Physiology and Microbiology, Faculty of Biology, C. José Antonio Novais, 12, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
- Correspondence:
| | - Ángeles Aguilera
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Carolina G. de Figueras
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Patricia de Francisco
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
| | - Sanna Olsson
- Department of Forest Ecology and Genetics, Forest Research Centre (INIA, CSIC), Carretera de La Coruña, km 7.5, 28040 Madrid, Spain;
| | - Fernando Puente-Sánchez
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, 756 51 Uppsala, Sweden;
| | - José Eduardo González-Pastor
- Department of Molecular Biology, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain; (Á.A.); (C.G.d.F.); (P.d.F.); (J.E.G.-P.)
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Is Genetic Engineering a Route to Enhance Microalgae-Mediated Bioremediation of Heavy Metal-Containing Effluents? MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27051473. [PMID: 35268582 PMCID: PMC8911655 DOI: 10.3390/molecules27051473] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/19/2022]
Abstract
Contamination of the biosphere by heavy metals has been rising, due to accelerated anthropogenic activities, and is nowadays, a matter of serious global concern. Removal of such inorganic pollutants from aquatic environments via biological processes has earned great popularity, for its cost-effectiveness and high efficiency, compared to conventional physicochemical methods. Among candidate organisms, microalgae offer several competitive advantages; phycoremediation has even been claimed as the next generation of wastewater treatment technologies. Furthermore, integration of microalgae-mediated wastewater treatment and bioenergy production adds favorably to the economic feasibility of the former process—with energy security coming along with environmental sustainability. However, poor biomass productivity under abiotic stress conditions has hindered the large-scale deployment of microalgae. Recent advances encompassing molecular tools for genome editing, together with the advent of multiomics technologies and computational approaches, have permitted the design of tailor-made microalgal cell factories, which encompass multiple beneficial traits, while circumventing those associated with the bioaccumulation of unfavorable chemicals. Previous studies unfolded several routes through which genetic engineering-mediated improvements appear feasible (encompassing sequestration/uptake capacity and specificity for heavy metals); they can be categorized as metal transportation, chelation, or biotransformation, with regulation of metal- and oxidative stress response, as well as cell surface engineering playing a crucial role therein. This review covers the state-of-the-art metal stress mitigation mechanisms prevalent in microalgae, and discusses putative and tested metabolic engineering approaches, aimed at further improvement of those biological processes. Finally, current research gaps and future prospects arising from use of transgenic microalgae for heavy metal phycoremediation are reviewed.
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Tripathi S, Poluri KM. Heavy metal detoxification mechanisms by microalgae: Insights from transcriptomics analysis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 285:117443. [PMID: 34090077 DOI: 10.1016/j.envpol.2021.117443] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/07/2021] [Accepted: 05/20/2021] [Indexed: 05/20/2023]
Abstract
Heavy metal pollution in ecosystem is a global threat. The associated toxicity and carcinogenic nature of heavy metals/metalloids such as mercury, cadmium, lead, and arsenic are imposing a severe risk to both ecological diversity and human lives. Harnessing the adaptive feature of microalgae for remediating toxic heavy metal has reached a milestone in past few decades. Transcriptomics analyses have provided mechanistic insights to map the dynamics of cellular events under heavy metal stress, thus deciphering the strategic responses of microalgae. Here, the present review comprehensively addresses the elicited molecular responses of microalgae to detoxify the heavy metal stress. The review highlights the intricate role of biochemical components and signaling networks mediating stress responsive transitions of microalgae at physiological level. Furthermore, the differential gene expression signifying the transporters involved in uptake, distribution/sequestration, and efflux of heavy metal has also been reviewed. In a nutshell, this study provided a comprehensive understanding of the molecular mechanisms adopted by microalgae at transcriptome level to nullify the oxidative stress while detoxifying the heavy metals.
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Affiliation(s)
- Shweta Tripathi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India
| | - Krishna Mohan Poluri
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India; Centre for Transportation Systems, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India.
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Danouche M, El Ghachtouli N, El Arroussi H. Phycoremediation mechanisms of heavy metals using living green microalgae: physicochemical and molecular approaches for enhancing selectivity and removal capacity. Heliyon 2021; 7:e07609. [PMID: 34355100 PMCID: PMC8322293 DOI: 10.1016/j.heliyon.2021.e07609] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/02/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022] Open
Abstract
Heavy metal (HM) contamination of water bodies is a serious global environmental problem. Because they are not biodegradable, they can accumulate in food chains, causing various signs of toxicity to exposed organisms, including humans. Due to its effectiveness, low cost, and ecological aspect, phycoremediation, or the use of microalgae's ecological functions in the treatment of HMs contaminated wastewater, is one of the most recommended processes. This study aims to examine in depth the mechanisms involved in the phycoremediation of HMs by microalgae, it also provides an overview of the prospects for improving the productivity, selectivity, and cost-effectiveness of this bioprocess through physicochemical and genetic engineering applications. Firstly, this review proposes a detailed examination of the biosorption interactions between cell wall functional groups and HMs, and their complexation with extracellular polymeric substances released by microalgae in the extracellular environment under stress conditions. Subsequently, the metal transporters involved in the intracellular bioaccumulation of HMs as well as the main intracellular mechanisms including compartmentalization in cell organelles, enzymatic biotransformation, or photoreduction of HMs were also extensively reviewed. In the last section, future perspectives of physicochemical and genetic approaches that could be used to improve the phytoremediation process in terms of removal efficiency, selectivity for a targeted metal, or reduction of treatment time and cost are discussed, which paves the way for large-scale application of phytoremediation processes.
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Affiliation(s)
- Mohammed Danouche
- Green Biotechnology Center, Moroccan Foundation for Advanced Science, Innovation and Research (MAScIR), Rabat, Morocco
- Microbial Biotechnology and Bioactive Molecules Laboratory, Sciences and Technologies Faculty, Sidi Mohamed Ben Abdellah University, Fez, Morocco
| | - Naïma El Ghachtouli
- Microbial Biotechnology and Bioactive Molecules Laboratory, Sciences and Technologies Faculty, Sidi Mohamed Ben Abdellah University, Fez, Morocco
| | - Hicham El Arroussi
- Green Biotechnology Center, Moroccan Foundation for Advanced Science, Innovation and Research (MAScIR), Rabat, Morocco
- AgroBioScience (AgBS), Mohammed VI Polytechnic University (UM6P), Benguerir, Morocco
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Mavrakis E, Mavroudakis L, Lydakis-Simantiris N, Pergantis SA. Investigating the Uptake of Arsenate by Chlamydomonas reinhardtii Cells and its Effect on their Lipid Profile using Single Cell ICP–MS and Easy Ambient Sonic-Spray Ionization–MS. Anal Chem 2019; 91:9590-9598. [DOI: 10.1021/acs.analchem.9b00917] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Emmanouil Mavrakis
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Voutes Campus, Heraklion 70013, Greece
| | - Leonidas Mavroudakis
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Voutes Campus, Heraklion 70013, Greece
| | - Nikos Lydakis-Simantiris
- Laboratory of Environmental Chemistry and of Biochemical Processes, Department of Agriculture, Hellenic Mediterranean University, Chania 73133, Greece
| | - Spiros A. Pergantis
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Voutes Campus, Heraklion 70013, Greece
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Chen L, Zhang L. Arsenic speciation in Asiatic algae: Case studies in Asiatic continent. ARSENIC SPECIATION IN ALGAE 2019. [DOI: 10.1016/bs.coac.2019.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Wang Y, Zhang C, Zheng Y, Ge Y. Phytochelatin synthesis in Dunaliella salina induced by arsenite and arsenate under various phosphate regimes. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 136:150-160. [PMID: 27865115 DOI: 10.1016/j.ecoenv.2016.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/04/2016] [Accepted: 11/07/2016] [Indexed: 06/06/2023]
Abstract
This study investigated the dynamic variations in thiol compounds, including cysteine (Cys), glutathione (GSH), and phytochelatins (PCs), in Dunaliella salina samples exposed to arsenite [As(III)] and arsenate [As(V)] under various phosphate (PO43-) regimes. Our results showed that GSH was the major non-protein sulfhydryl compound in D. salina cells. As(III) and As(V) induced PC syntheses in D. salina. PC2, PC3, and PC4 were all found in algal cells; the PC concentrations decreased gradually while exposed to As for 3 d. The synthesis of PC2-3 was significantly affected by As(III) and As(V) concentrations in the cultures. More PCs were detected in the As(V)-treated algal cells compared with the As(III) treatment. PC levels increased with As(III)/As(V) amount in the medium, but remained stable after 112μgL-1 As(V) exposure. In contrast, significant (p<0.001) positive correlations were observed between PC synthesis and intracellular As(III) content or As accumulation in As(III)-treated algal cells during the 72-h exposure. PO43- had a significant influence on the PC synthesis in algal cells, irrespective of the As-treated species. Reductions in As uptake and subsequent PC synthesis by D. salina were observed as the PO43- concentration in the growth medium increased. L-Buthionine sulfoximine (BSO) differentially influenced PC synthesis in As-treated D. salina under different extracellular PO43- regimes. Overall, our data demonstrated that the production of GSH and PCs was affected by PO43- and that these thiols played an important role in As detoxification by D. salina.
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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 Quality and Safety, 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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Koechler S, Bertin PN, Plewniak F, Baltenweck R, Casiot C, Heipieper HJ, Bouchez O, Arsène-Ploetze F, Hugueney P, Halter D. Arsenite response in Coccomyxa sp. Carn explored by transcriptomic and non-targeted metabolomic approaches. Environ Microbiol 2016; 18:1289-300. [PMID: 26769162 DOI: 10.1111/1462-2920.13227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 12/20/2015] [Accepted: 01/12/2016] [Indexed: 12/17/2022]
Abstract
Arsenic is a toxic metalloid known to generate an important oxidative stress in cells. In the present study, we focused our attention on an alga related to the genus Coccomyxa, exhibiting an extraordinary capacity to resist high concentrations of arsenite and arsenate. The integrated analysis of high-throughput transcriptomic data and non-targeted metabolomic approaches highlighted multiple levels of protection against arsenite. Indeed, Coccomyxa sp. Carn induced a set of transporters potentially preventing the accumulation of this metalloid in the cells and presented a distinct arsenic metabolism in comparison to another species more sensitive to that compound, i.e. Euglena gracilis, especially in regard to arsenic methylation. Interestingly, Coccomyxa sp. Carn was characterized by a remarkable accumulation of the strong antioxidant glutathione (GSH). Such observation could explain the apparent low oxidative stress in the intracellular compartment, as suggested by the transcriptomic analysis. In particular, the high amount of GSH in the cell could play an important role for the tolerance to arsenate, as suggested by its partial oxidation into oxidized glutathione in presence of this metalloid. Our results therefore reveal that this alga has acquired multiple and original defence mechanisms allowing the colonization of extreme ecosystems such as acid mine drainages.
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Affiliation(s)
- Sandrine Koechler
- Génétique Moléculaire, Génomique et Microbiologie, Département Microorganismes, Génomes, Environnement UMR7156 Université de Strasbourg/CNRS, 28 rue Goethe, 67083, Strasbourg Cedex, France
| | - Philippe N Bertin
- Génétique Moléculaire, Génomique et Microbiologie, Département Microorganismes, Génomes, Environnement UMR7156 Université de Strasbourg/CNRS, 28 rue Goethe, 67083, Strasbourg Cedex, France
| | - Frédéric Plewniak
- Génétique Moléculaire, Génomique et Microbiologie, Département Microorganismes, Génomes, Environnement UMR7156 Université de Strasbourg/CNRS, 28 rue Goethe, 67083, Strasbourg Cedex, France
| | - Raymonde Baltenweck
- Unité Mixte de Recherche Santé de la Vigne et Qualité du Vin, Equipe Métabolisme secondaire de la vigne INRA, 68021, Colmar, France
| | - Corinne Casiot
- Hydrosciences Montpellier, UMR 5569 (CNRS, IRD, UM1, UM2), Université Montpellier 2, Place E. Bataillon, 34095, Montpellier Cedex 05, France
| | - Hermann J Heipieper
- Helmholtz Centre for Environmental Research - UFZ, Department Environmental Biotechnology, Permoserstr. 15, Leipzig, Germany
| | - Olivier Bouchez
- GeT-PlaGe (Plateforme Génomique) Campus INRA, 24 Chemin de Borde Rouge - Auzeville CS 52627, 31326, Castanet-Tolosan, France
| | - Florence Arsène-Ploetze
- Génétique Moléculaire, Génomique et Microbiologie, Département Microorganismes, Génomes, Environnement UMR7156 Université de Strasbourg/CNRS, 28 rue Goethe, 67083, Strasbourg Cedex, France
| | - Philippe Hugueney
- Unité Mixte de Recherche Santé de la Vigne et Qualité du Vin, Equipe Métabolisme secondaire de la vigne INRA, 68021, Colmar, France
| | - David Halter
- Unité Mixte de Recherche Santé de la Vigne et Qualité du Vin, Equipe Métabolisme secondaire de la vigne INRA, 68021, Colmar, France
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Roncarati F, Sáez CA, Greco M, Gledhill M, Bitonti MB, Brown MT. Response differences between Ectocarpus siliculosus populations to copper stress involve cellular exclusion and induction of the phytochelatin biosynthetic pathway. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 159:167-75. [PMID: 25546007 DOI: 10.1016/j.aquatox.2014.12.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/09/2014] [Accepted: 12/10/2014] [Indexed: 06/04/2023]
Abstract
Some populations of brown seaweed species inhabit metal-polluted environments and can develop tolerance to metal stress, but the mechanisms by which this is accomplished are still to be elucidated. To address this, the responses of two strains of the model brown alga Ectocarpus siliculosus isolated from sites with different histories of metal contamination exposed to total copper (CuT) concentrations ranging between 0 and 2.4 μM for 10 days were investigated. The synthesis of the metal-chelator phytochelatin (PCs) and relative levels of transcripts encoding the enzymes γ-glutamylcysteine synthetase (γ-GCS), glutathione synthase (GS) and phytochelatin synthase (PCS) that participate in the PC biosynthetic pathway were measured, along with the effects on growth, and adsorption and uptake of Cu. Growth of strain LIA, from a pristine site in Scotland, was inhibited to a greater extent, and at lower concentrations, than that of Es524, isolated from a Cu-contaminated site in Chile. Concentrations of intra-cellular Cu were higher and the exchangeable fraction was lower in LIA than Es524, especially at the highest exposure levels. Total glutathione concentrations increased in both strains with Cu exposure, whereas total PCs levels were higher in Es524 than LIA; PC2 and PC3 were detected in Es524 but PC2 only was found in LIA. The greater production and levels of polymerisation of PCs in Es524 can be explained by the up-regulation of genes encoding for key enzymes involved in the synthesis of PCs. In Es524 there was an increase in the transcripts of γ-GCS, GS and PCS, particularly under high Cu exposure, whereas in LIA4 transcripts of γ-GCS1 increased only slightly, γ-GCS2 and GS decreased and PCS did not change. The consequences of higher intra-cellular concentrations of Cu, lower production of PCs, and lower expression of enzymes involved in GSH-PCs synthesis may be contributing to an induced oxidative stress condition in LIA, which explains, at least in part, the observed sensitivity of LIA to Cu. Therefore, responses to Cu exposure in E. siliculosus relate to the contamination histories of the locations from where the strains were isolated and differences in Cu exclusion and PCs production are in part responsible for the development of intra-specific resistance.
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Affiliation(s)
- Francesca Roncarati
- School of Marine Science and Engineering, Faculty of Science and Environment, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK
| | - Claudio A Sáez
- School of Marine Science and Engineering, Faculty of Science and Environment, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK; Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, casilla 40 correo 33, Santiago, Chile; Departamento de Medio Ambiente, Facultad de Ingeniería, Universidad de Playa Ancha, Casilla 34-V, Valparaíso, Chile
| | - Maria Greco
- Laboratory of Plant Cyto-Physiology, University of Calabria, Arcavata di Rende, Cosenza 87036, Italy
| | - Martha Gledhill
- Helmholtz Centre for Ocean Research, GEOMAR, Wischhofstrasse 1-3, Build. 12, D-24148 Kiel, Germany
| | - Maria B Bitonti
- Laboratory of Plant Cyto-Physiology, University of Calabria, Arcavata di Rende, Cosenza 87036, Italy
| | - Murray T Brown
- School of Marine Science and Engineering, Faculty of Science and Environment, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
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Mikulic P, Beardall J. Contrasting ecotoxicity effects of zinc on growth and photosynthesis in a neutrophilic alga (Chlamydomonas reinhardtii) and an extremophilic alga (Cyanidium caldarium). CHEMOSPHERE 2014; 112:402-411. [PMID: 25048933 DOI: 10.1016/j.chemosphere.2014.04.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/10/2014] [Accepted: 04/16/2014] [Indexed: 06/03/2023]
Abstract
This study aimed to determine the contrasting ecotoxicity effects of zinc on growth and photosynthesis in a neutrophilic (Chlamydomonas reinhardtii) and an extremophilic (Cyanidium caldarium) alga. Experiments were carried out to see if cells acclimated to zinc would respond differently to cells that were unexposed to zinc. The study also aimed to see if extremophiles displayed different acclimation properties to neutrophiles. Results showed that the neutrophilic alga C. reinhardtii, was more susceptible to free zinc and had a lower IC50 value than the extremophile, however its stress response protected the photosynthetic apparatus. Upon acclimation, the photosynthetic abilities of C. reinhardtii were not significantly compromised when exposed to toxic levels of free zinc. On the other hand, C. caldarium had a stress response which allowed it to tolerate significantly higher amounts of free zinc in its environment compared to C. reinhardtii , however the stress response did not protect the photosynthetic apparatus, and upon acclimation C. caldarium was no better equipped to protect its photosynthetic integrity than unexposed cells.
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Affiliation(s)
- Paulina Mikulic
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia.
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
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Walliwalagedara C, Keulen H, Willard B, Wei R. Differential Proteome Analysis of <i>Chlamydomonas reinhardtii</i> Response to Arsenic Exposure. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ajps.2012.36092] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Jiang Y, Purchase D, Jones H, Garelick H. Effects of arsenate (AS5+) on growth and production of glutathione (GSH) and phytochelatins (PCS) in Chlorella vulgaris. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2011; 13:834-844. [PMID: 21972522 DOI: 10.1080/15226514.2010.525560] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The effect of arsenate (As5+) on growth and chlorophyll a production in Chlorella vulgaris, its removal by C. vulgaris and the role of glutathione (GSH) and phytochelatins (PCs) were investigated. C. vulgaris was tolerant to As5+ at up to 200 mg/L and was capable of consistently removing around 70% of the As5+ present in growth media over a wide range of exposure concentrations. Spectral analysis revealed that PCs and their arsenic-combined complexes were absent, indicating that the high bioaccumulation and tolerance to arsenic observed was not due to intracellular chelation. In contrast, GSH was found in all samples ranging from 0.8 mg/L in the control to 6.5 mg/L in media containing 200 mg/L As5+ suggesting that GSH plays a more prominent role in the detoxification of As5+ in C. vulgaris than PC. At concentrations below 100 mg/L cell surface binding and other mechanisms may play the primary role in As5+ detoxification, whereas above this concentration As5+ begins to accumulate inside the algal cells and activates a number of intracellular cell defense mechanisms, such as increased production of GSH. The overall findings complement field studies which suggest C. vulgaris as an increasingly promising low cost As phytoremediation method for developing countries.
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Affiliation(s)
- Ying Jiang
- Department of Natural Sciences, School of Health and Social Sciences, Middlesex University, The Burroughs, London, UK
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Wang MJ, Wang WX. Cadmium sensitivity, uptake, subcellular distribution and thiol induction in a marine diatom: exposure to cadmium. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2011; 101:377-386. [PMID: 21216348 DOI: 10.1016/j.aquatox.2010.11.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Revised: 10/14/2010] [Accepted: 11/19/2010] [Indexed: 05/30/2023]
Abstract
The aims of this study were to (1) evaluate the changes in the Cd tolerance of a marine diatom after exposure under different Cd concentrations for various durations and (2) to explore the potential subcellular and biochemical mechanisms underlying these changes. The 72-h toxicity, short-term Cd uptake, subcellular Cd distribution, as well as the synthesis of phytochelatins (PCs) were measured in a marine diatom Thalassiosira nordenskioeldii after exposure to a range of free Cd ion concentrations ([Cd(2+)], 0.01-84nM) for 1-15 days. Surprisingly, the diatoms did not acquire higher resistance to Cd after exposure; instead their sensitivity to Cd increased with a higher exposed [Cd(2+)] and a longer exposure period. The underlying mechanisms could be traced to the responses of Cd cellular accumulation and the intrinsic detoxification ability of the preconditioned diatoms. Generally, exposure to a higher [Cd(2+)] and for a longer period increased the Cd uptake rate, cellular accumulation, as well as the Cd concentration in metal-sensitive fraction (MSF) in these diatoms. In contrast, although PCs were induced by the environmental Cd stress (with PC(2) being the most affected), the increased intracellular Cd to PC-SH ratio implied that the PCs' detoxification ability had reduced after Cd exposure. All these responses resulted in an elevated Cd sensitivity as exposed [Cd(2+)] and duration increased. This study shows that the physiological/biochemical and kinetic responses of phytoplankton upon metal exposure deserve further investigation.
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Affiliation(s)
- Meng-Jiao Wang
- State Key Laboratory in Marine Pollution, Section of Marine Ecology and Biotechnology, Division of Life Science, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong
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Suárez C, Torres E, Pérez-Rama M, Herrero C, Abalde J. Cadmium toxicity on the freshwater microalga Chlamydomonas moewusii Gerloff: Biosynthesis of thiol compounds. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2010; 29:2009-2015. [PMID: 20821658 DOI: 10.1002/etc.242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Cadmium (Cd) toxicity and production of different thiols (phytochelatins, glutathione, gamma-Glu-Cys and cysteine) were studied in the microalga Chlamydomonas moewusii exposed to different concentrations of this metal (1, 2, 4, 6, 8, and 10 mg/L) for 96 h. The inhibitory effect of Cd on growth was demonstrated. The value of EC50 (metal concentration which reduces the population growth to 50% of the control) obtained for this microalga was estimated at 4.1 +/- 0.8 mg/L of Cd after 96 h of exposure. The amount of thiol compounds synthesized by C. moewusii changed with Cd concentration. Cysteine concentrations were significantly higher compared to those of gamma-Glu-Cys and glutathione in all the Cd concentrations assayed. The amino acid cysteine reached its higher levels in those cultures in which a decrease in the concentration of phytochelatins (PCs) was observed. Both cysteine and glutathione concentrations showed significant differences along the Cd concentrations assayed, while the amount of gamma-Glu-Cys detected remained stable. The PCs detected were of two, three, and four subunits. The level of PC(2) was higher than that of PC(3) and PC(4). PC(4) was detected only in the cultures exposed to the Cd concentrations of 1 and 2 mg/L, in which the synthesis of phytochelatins was higher. A rapid increase in the production of PC(2) and PC(3) was observed up to a Cd concentration of 2 mg/L, after which their levels began to decrease. Phytochelatins were not detected in cultures without Cd (controls) and in those exposed to the maximum Cd concentration (10 mg/L), in which cell growth was completely inhibited.
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Affiliation(s)
- Cristina Suárez
- Laboratorio de Microbiología, Facultad de Ciencias, Universidade da Coruña, Alejandro de La Sota, No. 1. 15008. La Coruña, Spain
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Analytical approach for characterization of cadmium-induced thiol peptides—a case study using Chlamydomonas reinhardtii. Anal Bioanal Chem 2009; 395:1737-47. [DOI: 10.1007/s00216-009-2921-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/11/2009] [Accepted: 06/15/2009] [Indexed: 12/31/2022]
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16
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Huang Z, Li L, Huang G, Yan Q, Shi B, Xu X. Growth-inhibitory and metal-binding proteins in Chlorella vulgaris exposed to cadmium or zinc. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2009; 91:54-61. [PMID: 19019465 DOI: 10.1016/j.aquatox.2008.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 10/01/2008] [Accepted: 10/04/2008] [Indexed: 05/27/2023]
Abstract
Phytochelatins, with the general structure of (gamma-Glu-Cys)n-Gly (n=2-11), are usually recognized as being strongly induced by metals in microalgae and play an important role in the detoxification of heavy metals in environment. However, there have been few studies on metallothionein (MT) synthesis in Chlorella vulgaris (C. vulgaris) exposed to heavy metals. The present study describes the growth inhibition of C. vulgaris exposed to different concentrations of cadmium and zinc, and the induction of metal-binding MT-like proteins in the cells. The amounts of metal-binding proteins, induced in the alga exposed to different concentrations of Cd and Zn, were analyzed with a size-exclusion HPLC coupled to ICP-MS. After being purified with a gel filtration column (Sephadex G-75, 3.5cmx80cm) and a desalting column (G-25, 1.5cmx30cm), the isoforms and sub-isoforms of Zn-binding protein were characterized by a reverse phase-HPLC coupled to electrospray ionization and a triple quadrupole mass spectrometer (HPLC-ESI-MS/MS). In addition, the ultraviolet spectra of purified Zn-binding proteins were analyzed in media with different pH values. The results showed that the significant inhibitory effects (at p<0.05) on the cell growth were observed when excessive metals such as 80micromoll(-1) of Cd, and 60 and 80micromoll(-1) of Zn were added. The Cd/Zn-binding proteins induced in C. vulgaris exposed to Cd and Zn were referred to as Cd/Zn-MT-like proteins in which the mean molecular mass of the apo-MT-like was 6152Da. The induced Cd/Zn-MT-like proteins might be involved in the detoxification of heavy metals, such as cadmium and zinc, by the alga.
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Affiliation(s)
- Zhiyong Huang
- College of Bioengineering, Jimei University, Xiamen, 361021, P R China.
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Shibagaki N, Grossman A. The State of Sulfur Metabolism in Algae: From Ecology to Genomics. SULFUR METABOLISM IN PHOTOTROPHIC ORGANISMS 2008. [DOI: 10.1007/978-1-4020-6863-8_13] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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García-Ríos V, Freile-Pelegrín Y, Robledo D, Mendoza-Cózatl D, Moreno-Sánchez R, Gold-Bouchot G. Cell wall composition affects Cd2+ accumulation and intracellular thiol peptides in marine red algae. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2007; 81:65-72. [PMID: 17161878 DOI: 10.1016/j.aquatox.2006.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2006] [Revised: 11/03/2006] [Accepted: 11/04/2006] [Indexed: 05/12/2023]
Abstract
Two red macroalgae species, Gracilaria cornea and Chondrophycus poiteaui, were evaluated for their intra and extracellular Cd2+ accumulation capacity, photosynthetic response and thiol peptide production. Algae were exposed for 3 and 7 days to 0.1 and 1 microg CdCl2 ml(-1) (0.89 and 8.9 microM). Intracellular accumulation of Cd2+ by G. cornea was relatively low, only comprising 20% of total metal (intracellular+extracellular). In contrast, C. poiteaui accumulated intracellularly close to 100% of total Cd2+. In both species, metal uptake was dependent on the external Cd2+ concentration, metal exposure time and cell wall composition. In response to Cd2+ exposure, low amounts of thiol peptides were synthesized and the major difference between G. cornea and C. poiteaui was in the cell wall composition. The absence of insoluble polysaccharides in the cell wall of C. poiteaui suggested that this insoluble fraction might be involved in establishing an efficient barrier for the intracellular accumulation of Cd2+. This is the first study in which the cell wall composition, its influence on Cd2+ accumulation and intracellular responses in red macroalgae are evaluated.
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Affiliation(s)
- Virginia García-Ríos
- Departamento de Recursos del Mar, CINVESTAV-IPN, Unidad Mérida, Apdo. Postal 73-Cordemex, Mérida, Yucatán 97310, México
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