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Kong D, Ma H, Zhu C, Hao Y, Li C. Unraveling the toxicity response and metabolic compensation mechanism of tannic acid-Cr(III) complex on alga Raphidocelis subcapitata. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172034. [PMID: 38657806 DOI: 10.1016/j.scitotenv.2024.172034] [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: 01/22/2024] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/26/2024]
Abstract
Due to their assembly properties and variable molecular weights, the potential biological toxicity effects of macromolecular organic ligand heavy metal complexes are more difficult to predict and their mechanisms are more complex. This study unraveled the toxicity response and metabolic compensation mechanism of tannic acid-Cr(III) (TA-Cr(III)) complex on alga Raphidocelis subcapitata using multi-omics approaches. Results showed TA-Cr(III) complex caused oxidative damage and photosystem disruption, destroying the cell morphology and inhibiting algal growth by >80 % at high exposure levels. TA-Cr(III) complex stress down-regulated proteins linked to proliferation, photosynthesis and antioxidation while upregulating carbon fixation, TCA cycle and amino acid metabolism. The increase of fumarate, citrate, isocitrate and semialdehyde succinate was validated by metabolomics analysis, which improved the TCA cycle, amino acid metabolism and carbon fixation. Activation of the above cellular processes somewhat compensated for the inhibition of algal photosynthesis by TA-Cr(III) complex exposure. In conclusion, physiological toxicity coupled with downstream metabolic compensation in response to Cr(III) complex of macromolecular was characterized in Raphidocelis subcapitata, unveiling the adaptive mechanism of algae under the stress of heavy metal complexes with macromolecular organic ligands.
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Affiliation(s)
- Deyi Kong
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi 'an 710021, PR China
| | - Hongrui Ma
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi 'an 710021, PR China.
| | - Chao Zhu
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi 'an 710021, PR China
| | - Yongyong Hao
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi 'an 710021, PR China
| | - Chengtao Li
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi 'an 710021, PR China
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Thabet J, Elleuch J, Martínez F, Abdelkafi S, Hernández LE, Fendri I. Characterization of cellular toxicity induced by sub-lethal inorganic mercury in the marine microalgae Chlorococcum dorsiventrale isolated from a metal-polluted coastal site. CHEMOSPHERE 2023; 338:139391. [PMID: 37414298 DOI: 10.1016/j.chemosphere.2023.139391] [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: 05/22/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 07/08/2023]
Abstract
Mercury (Hg) is a global pollutant that affects numerous marine aquatic ecosystems. We isolated Chlorococcum dorsiventrale Ch-UB5 microalga from coastal areas of Tunisia suffering from metal pollution and analyzed its tolerance to Hg. This strain accumulated substantial amounts of Hg and was able to remove up to 95% of added metal after 24 and 72 h in axenic cultures. Mercury led to lesser biomass growth, higher cell aggregation, significant inhibition of photochemical activity, and appearance of oxidative stress and altered redox enzymatic activities, with proliferation of starch granules and neutral lipids vesicles. Such changes matched the biomolecular profile observed using Fourier Transformed Infrared spectroscopy, with remarkable spectral changes corresponding to lipids, proteins and carbohydrates. C. dorsiventrale accumulated the chloroplastic heat shock protein HSP70B and the autophagy-related ATG8 protein, probably to counteract the toxic effects of Hg. However, long-term treatments (72 h) usually resulted in poorer physiological and metabolic responses, associated with acute stress. C. dorsiventrale has potential use for Hg phycoremediation in marine ecosystems, with the ability to accumulating energetic reserves that could be used for biofuel production, supporting the notion of using of C. dorsiventrale for sustainable green chemistry in parallel to metal removal.
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Affiliation(s)
- Jihen Thabet
- Laboratoire de Biotechnologies Végétales Appliquées à l'Amélioration des Cultures, Faculté des Sciences de Sfax, Université de Sfax, Sfax, Tunisia; Laboratory of Plant Physiology-Department of Biology, Universidad Autónoma Madrid, Darwin 2, ES28049, Madrid, Spain
| | - Jihen Elleuch
- Laboratoire de Génie Enzymatique et Microbiologie, Equipe Biotechnologie des Algues, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, Sfax, Tunisia
| | - Flor Martínez
- Laboratory of Plant Physiology-Department of Biology, Universidad Autónoma Madrid, Darwin 2, ES28049, Madrid, Spain
| | - Slim Abdelkafi
- Laboratoire de Génie Enzymatique et Microbiologie, Equipe Biotechnologie des Algues, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, Sfax, Tunisia
| | - Luis Eduardo Hernández
- Laboratory of Plant Physiology-Department of Biology, Universidad Autónoma Madrid, Darwin 2, ES28049, Madrid, Spain.
| | - Imen Fendri
- Laboratoire de Biotechnologies Végétales Appliquées à l'Amélioration des Cultures, Faculté des Sciences de Sfax, Université de Sfax, Sfax, Tunisia
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Schmollinger S, Chen S, Merchant SS. Quantitative elemental imaging in eukaryotic algae. Metallomics 2023; 15:mfad025. [PMID: 37186252 PMCID: PMC10209819 DOI: 10.1093/mtomcs/mfad025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 03/03/2023] [Indexed: 05/17/2023]
Abstract
All organisms, fundamentally, are made from the same raw material, namely the elements of the periodic table. Biochemical diversity is achieved by how these elements are utilized, for what purpose, and in which physical location. Determining elemental distributions, especially those of trace elements that facilitate metabolism as cofactors in the active centers of essential enzymes, can determine the state of metabolism, the nutritional status, or the developmental stage of an organism. Photosynthetic eukaryotes, especially algae, are excellent subjects for quantitative analysis of elemental distribution. These microbes utilize unique metabolic pathways that require various trace nutrients at their core to enable their operation. Photosynthetic microbes also have important environmental roles as primary producers in habitats with limited nutrient supplies or toxin contaminations. Accordingly, photosynthetic eukaryotes are of great interest for biotechnological exploitation, carbon sequestration, and bioremediation, with many of the applications involving various trace elements and consequently affecting their quota and intracellular distribution. A number of diverse applications were developed for elemental imaging, allowing subcellular resolution, with X-ray fluorescence microscopy (XFM, XRF) being at the forefront, enabling quantitative descriptions of intact cells in a non-destructive method. This Tutorial Review summarizes the workflow of a quantitative, single-cell elemental distribution analysis of a eukaryotic alga using XFM.
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Affiliation(s)
- Stefan Schmollinger
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA
- Departments of Molecular and Cell Biology and Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Si Chen
- X-ray Science Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Sabeeha S Merchant
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA 94720, USA
- Departments of Molecular and Cell Biology and Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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4
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Chen D, Wang G, Chen C, Feng Z, Jiang Y, Yu H, Li M, Chao Y, Tang Y, Wang S, Qiu R. The interplay between microalgae and toxic metal(loid)s: mechanisms and implications in AMD phycoremediation coupled with Fe/Mn mineralization. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131498. [PMID: 37146335 DOI: 10.1016/j.jhazmat.2023.131498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/10/2023] [Accepted: 04/24/2023] [Indexed: 05/07/2023]
Abstract
Acid mine drainage (AMD) is low-pH with high concentration of sulfates and toxic metal(loid)s (e.g. As, Cd, Pb, Cu, Zn), thereby posing a global environmental problem. For decades, microalgae have been used to remediate metal(loid)s in AMD, as they have various adaptive mechanisms for tolerating extreme environmental stress. Their main phycoremediation mechanisms are biosorption, bioaccumulation, coupling with sulfate-reducing bacteria, alkalization, biotransformation, and Fe/Mn mineral formation. This review summarizes how microalgae cope with metal(loid) stress and their specific mechanisms of phycoremediation in AMD. Based on the universal physiological characteristics of microalgae and the properties of their secretions, several Fe/Mn mineralization mechanisms induced by photosynthesis, free radicals, microalgal-bacterial reciprocity, and algal organic matter are proposed. Notably, microalgae can also reduce Fe(III) and inhibit mineralization, which is environmentally unfavorable. Therefore, the comprehensive environmental effects of microalgal co-occurring and cyclical opposing processes must be carefully considered. Using chemical and biological perspectives, this review innovatively proposes several specific processes and mechanisms of Fe/Mn mineralization that are mediated by microalgae, providing a theoretical basis for the geochemistry of metal(loid)s and natural attenuation of pollutants in AMD.
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Affiliation(s)
- Daijie Chen
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Guobao Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Chiyu Chen
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Zekai Feng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Yuanyuan Jiang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Hang Yu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Mengyao Li
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Yuanqing Chao
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Yetao Tang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Shizhong Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China.
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
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5
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Zhang B, Tang Y, Yu F, Peng Z, Yao S, Deng X, Long H, Wang X, Huang K. Translatomics and physiological analyses of the detoxification mechanism of green alga Chlamydomonas reinhardtii to cadmium toxicity. JOURNAL OF HAZARDOUS MATERIALS 2023; 448:130990. [PMID: 36860060 DOI: 10.1016/j.jhazmat.2023.130990] [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: 10/24/2022] [Revised: 02/02/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
Cadmium (Cd) is one of the most toxic pollutants found in aquatic ecosystems. Although gene expression in algae exposed to Cd has been studied at the transcriptional level, little is known about Cd impacts at the translational level. Ribosome profiling is a novel translatomics method that can directly monitor RNA translation in vivo. Here, we analyzed the translatome of the green alga Chlamydomonas reinhardtii following treatment with Cd to identify the cellular and physiological responses to Cd stress. Interestingly, we found that the cell morphology and cell wall structure were altered, and starch and high-electron-density particles accumulated in the cytoplasm. Several ATP-binding cassette transporters that responded to Cd exposure were identified. Redox homeostasis was adjusted to adapt to Cd toxicity, and GDP-L-galactose phosphorylase (VTC2), glutathione peroxidase (GPX5), and ascorbate were found to play important roles in maintaining reactive oxygen species homeostasis. Moreover, we found that the key enzyme of flavonoid metabolism, i.e., hydroxyisoflavone reductase (IFR1), is also involved in the detoxification of Cd. Thus, in this study, translatome and physiological analyses provided a complete picture of the molecular mechanisms of green algae cell responses to Cd.
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Affiliation(s)
- Baolong Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
| | - Yuxin Tang
- School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, Hubei, China
| | - Fei Yu
- School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, Hubei, China
| | - Zhao Peng
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, Hubei, China
| | - Sheng Yao
- School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, Hubei, China
| | - Xuan Deng
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
| | - Huan Long
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
| | - Xun Wang
- School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, Hubei, China
| | - Kaiyao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China.
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Aravind MK, Vignesh NS, Gayathri S, Anjitha N, Athira KM, Gunaseelan S, Arunkumar M, Sanjaykumar A, Karthikumar S, Ganesh Moorthy IM, Ashokkumar B, Pugazhendhi A, Varalakshmi P. Review on rewiring of microalgal strategies for the heavy metal remediation - A metal specific logistics and tactics. CHEMOSPHERE 2023; 313:137310. [PMID: 36460155 DOI: 10.1016/j.chemosphere.2022.137310] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 11/08/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Phycoremediation of heavy metals are gaining much attention and becoming an emerging practice for the metal removal in diverse environmental matrices. Still, the physicochemical state of metal polluted sites is often found to be complex and haphazard in nature due to the irregular discharge of wastes, that leads to the lack of conjecture on the application of microalgae for the metal bioremediation. Besides, the foresaid issues might be eventually ended up with futile effect to the polluted site. Therefore, this review is mainly focusing on interpretative assessment on pre-existing microalgal strategies and their merits and demerits for selected metal removal by microalgae through various process such as natural attenuation, nutritional amendment, chemical pretreatment, metal specific modification, immobilization and amalgamation, customization of genetic elements and integrative remediation approaches. Thus, this review provides the ideal knowledge for choosing an efficient metal remediation tactics based on the state of polluted environment. Also, this in-depth description would provide the speculative knowledge of counteractive action required for pass-over the barriers and obstacles during implementation. In addition, the most common metal removal mechanism of microalgae by adsorption was comparatively investigated with different metals through the principal component analysis by grouping various factor such as pH, temperature, initial metal concentration, adsorption capacity, removal efficiency, contact time in different microalgae. Conclusively, the suitable strategies for different heavy metals removal and addressing the complications along with their solution is comprehensively deliberated for metal removal mechanism in microalgae.
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Affiliation(s)
- Manikka Kubendran Aravind
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Nagamalai Sakthi Vignesh
- Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Santhalingam Gayathri
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Nair Anjitha
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Kottilinkal Manniath Athira
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Sathaiah Gunaseelan
- Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | - Malaisamy Arunkumar
- Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India; International Centre for Genetic Engineering and Biotechnology (ICGEB), Transcription Regulation Group, New Delhi, 110067, India
| | - Ashokkumar Sanjaykumar
- Department of Biotechnology, Bannari Amman Institute of Technology, Sathyamangalam, 638401, Tamil Nadu, India
| | - Sankar Karthikumar
- Department of Biotechnology, Kamaraj College of Engineering and Technology, Virudhunagar, 626001, Tamil Nadu, India
| | | | - Balasubramaniem Ashokkumar
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India
| | | | - Perumal Varalakshmi
- Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India.
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Thiriet-Rupert S, Gain G, Jadoul A, Vigneron A, Bosman B, Carnol M, Motte P, Cardol P, Nouet C, Hanikenne M. Long-term acclimation to cadmium exposure reveals extensive phenotypic plasticity in Chlamydomonas. PLANT PHYSIOLOGY 2021; 187:1653-1678. [PMID: 34618070 PMCID: PMC8566208 DOI: 10.1093/plphys/kiab375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/17/2021] [Indexed: 05/06/2023]
Abstract
Increasing industrial and anthropogenic activities are producing and releasing more and more pollutants in the environment. Among them, toxic metals are one of the major threats for human health and natural ecosystems. Because photosynthetic organisms play a critical role in primary productivity and pollution management, investigating their response to metal toxicity is of major interest. Here, the green microalga Chlamydomonas (Chlamydomonas reinhardtii) was subjected to short (3 d) or chronic (6 months) exposure to 50 µM cadmium (Cd), and the recovery from chronic exposure was also examined. An extensive phenotypic characterization and transcriptomic analysis showed that the impact of Cd on biomass production of short-term (ST) exposed cells was almost entirely abolished by long-term (LT) acclimation. The underlying mechanisms were initiated at ST and further amplified after LT exposure resulting in a reversible equilibrium allowing biomass production similar to control condition. This included modification of cell wall-related gene expression and biofilm-like structure formation, dynamics of metal ion uptake and homeostasis, photosynthesis efficiency recovery and Cd acclimation through metal homeostasis adjustment. The contribution of the identified coordination of phosphorus and iron homeostasis (partly) mediated by the main phosphorus homeostasis regulator, Phosphate Starvation Response 1, and a basic Helix-Loop-Helix transcription factor (Cre05.g241636) was further investigated. The study reveals the highly dynamic physiological plasticity enabling algal cell growth in an extreme environment.
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Affiliation(s)
- Stanislas Thiriet-Rupert
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000 Liège, Belgium
- Present address: Unité de Génétique des Biofilms, Département Microbiologie, Institut Pasteur, Paris, France
| | - Gwenaëlle Gain
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000 Liège, Belgium
- InBioS-PhytoSystems, Genetics and Physiology of Microalgae, University of Liège, 4000 Liège, Belgium
| | - Alice Jadoul
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000 Liège, Belgium
| | - Amandine Vigneron
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000 Liège, Belgium
| | - Bernard Bosman
- InBioS-PhytoSystems, Laboratory of Plant and Microbial Ecology, University of Liège, 4000 Liège, Belgium
| | - Monique Carnol
- InBioS-PhytoSystems, Laboratory of Plant and Microbial Ecology, University of Liège, 4000 Liège, Belgium
| | - Patrick Motte
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000 Liège, Belgium
| | - Pierre Cardol
- InBioS-PhytoSystems, Genetics and Physiology of Microalgae, University of Liège, 4000 Liège, Belgium
| | - Cécile Nouet
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000 Liège, Belgium
| | - Marc Hanikenne
- InBioS-PhytoSystems, Functional Genomics and Plant Molecular Imaging, University of Liège, 4000 Liège, Belgium
- Author for communication:
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Barón-Sola Á, Toledo-Basantes M, Arana-Gandía M, Martínez F, Ortega-Villasante C, Dučić T, Yousef I, Hernández LE. Synchrotron Radiation-Fourier Transformed Infrared microspectroscopy (μSR-FTIR) reveals multiple metabolism alterations in microalgae induced by cadmium and mercury. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126502. [PMID: 34214848 DOI: 10.1016/j.jhazmat.2021.126502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 06/13/2023]
Abstract
Toxic metals such as cadmium (Cd) and mercury (Hg) represent a threat to photosynthetic organisms of polluted aquatic ecosystems, and knowledge about mechanisms of toxicity is essential for appropriate assessment of environmental risks. We used Synchrotron Radiation-Fourier Transformed Infrared microspectroscopy (μSR-FTIR) to characterise major changes of biomolecules caused by Cd and Hg in the model green microalga Chlamydomonas reinhardtii. μSR-FTIR showed several metabolic alterations in different biochemical groups such as carbohydrates, proteins, and lipids in a time-dose dependent manner, with the strongest changes occurring at concentrations above 10 μM Cd and 15 μM Hg after short-term (24 h) treatments. This occurred in a context where metals triggered intracellular oxidative stress and chloroplast damage, along with autophagy induction by overexpressing AUTOPHAGY-RELATED PROTEIN 8 (ATG8). Thin layer chromatography analysis confirmed that toxic metals promoted remarkable changes in lipid profile, with higher degree of esterified fatty acid unsaturation as detected by gas chromatography coupled with mass spectrometry. Under Cd stress, there was specifically higher unsaturation of free fatty acids, while Hg led to stronger unsaturation in monogalactosyldiacylglycerol. μSR-FTIR spectroscopy proved as a valuable tool to identify biochemical alterations in microalgae, information that could be exploited to optimise approaches for metal decontamination.
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Affiliation(s)
- Ángel Barón-Sola
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Margarita Toledo-Basantes
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - María Arana-Gandía
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Flor Martínez
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Cristina Ortega-Villasante
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain
| | - Tanja Dučić
- CELLS ALBA, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, Barcelona, Spain
| | - Ibraheem Yousef
- CELLS ALBA, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, Barcelona, Spain
| | - Luis E Hernández
- Laboratory of Plant Physiology-Department of Biology/Research Centre for Biodiversity and Global Change, Universidad Autónoma Madrid, Darwin 2, ES28049 Madrid, Spain.
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