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Song X, Kong F, Liu BF, Song Q, Ren NQ, Ren HY. Combined transcriptomic and metabolomic analyses of temperature response of microalgae using waste activated sludge extracts for promising biodiesel production. WATER RESEARCH 2024; 251:121120. [PMID: 38237459 DOI: 10.1016/j.watres.2024.121120] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 12/05/2023] [Accepted: 01/07/2024] [Indexed: 02/12/2024]
Abstract
Waste activated sludge (WAS) as one of the major pollutants with a significant annual production, has garnered significant attention regarding its treatment and utilization. If improperly discharged, it not only caused environmental pollution but also led to the wastage of valuable resources. In this study, the microalgae growth and lipid accumulation using waste activated sludge extracts (WASE) under different temperature conditions were investigated. The highest lipid content (59.13%) and lipid productivity (80.41 mg L-1 d-1) were obtained at cultivation temperatures of 10 and 25 °C, respectively. It was found that microalgae can effectively utilize TN/TP/NH4+-N and other nutrients of WASE. The highest utilization rates of TP, TN and NH4+-N were achieved at a cultivation temperature of 10 °C, reaching 84.97, 77.49 and 92.32%, respectively. The algal fatty acids had carbon chains predominantly ranging from C14 to C18, making them suitable for biodiesel production. Additionally, a comprehensive analysis of transcriptomics and metabolomics revealed up-regulation of genes associated with triglyceride assembly, the antioxidant system of algal cells, and cellular autophagy, as well as the accumulation of metabolites related to the tricarboxylic acid (TCA) cycle and lipids. This study offers novel insights into the microscopic mechanisms of microalgae culture using WASE and approaches for the resource utilization of sludge.
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Affiliation(s)
- Xueting Song
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
| | - Fanying Kong
- School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
| | - Qingqing Song
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China
| | - Hong-Yu Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China.
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Bamary Z, Einali A. Changes in Carbon Partitioning and Pattern of Antioxidant Enzyme Activity Induced by Arginine Treatment in the Green Microalga Dunaliella salina Under Long-Term Salinity. MICROBIAL ECOLOGY 2022; 84:198-212. [PMID: 34396460 DOI: 10.1007/s00248-021-01843-3] [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: 04/19/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
In this work, the effects of arginine (Arg) on biochemical responses and antioxidant enzyme activity in the green microalga Dunaliella salina grown at different salt concentrations were investigated. Suspensions adapted with the concentrations of 1, 2, and 3 M NaCl were treated at the exponential growth phase with a concentration of 5 mM Arg. Salt stress was associated with a large decrease in the number of cells and non-reducing sugar levels but accumulated higher amounts of chlorophyll, β-carotene, reducing sugar, starch, total protein, free amino acid, and glycerol. Increased levels of protein carbonylation, lipid peroxidation, proteolysis, hydrogen peroxide, and antioxidant enzyme activity also occurred during salinity. Arg treatment changed the pattern of biochemical responses in the cells grown at high salinity by directing carbon flow to the biosynthesis of non-reducing sugars instead of starch, lowering levels of hydrogen peroxide, and downregulating antioxidant enzyme activity, but the levels of lipid peroxidation, glycerol, and β-carotene remained nearly unchanged. These results suggest that Arg treatment alleviates salinity-induced oxidative stress in D. salina cells by modifying carbon partitioning and inducing signaling molecules rather than antioxidant enzymes.
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Affiliation(s)
- Zahra Bamary
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Alireza Einali
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran.
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3
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A chitosan-vitamin C based injectable hydrogel improves cell survival under oxidative stress. Int J Biol Macromol 2022; 202:102-111. [PMID: 35038464 DOI: 10.1016/j.ijbiomac.2022.01.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/21/2021] [Accepted: 01/06/2022] [Indexed: 11/24/2022]
Abstract
Stem cell transplantation technology provides the cell reconstruction of damaged heart a completely new therapy approach. Due to the inappropriate microenvironment such as reactive oxygen radicals caused by ischemic infarct, the survival and retention rates of cell transplantation are not desirable. A thermo sensitive chitosan-vitamin C (CSVC) hydrogel scaffold was developed to reduce oxidative stress injury after myocardial infarction, thereby increasing the cell survival rate of cell transplantation. Vitamin C was conjugated on the chitosan chain by electrostatic adsorption. Compared to chitosan, CSVC complex had a higher solubility and stronger antioxidant property. CSVC hydrogel has suitable gelation time and injectable properties. Scanning electron microscopy showed that chitosan hydrogels had three-dimensional porous structure with irregular pores interconnected throughout the construct. Live/dead and H&E staining results showed that CSVC hydrogel can support the survival and adhesion of cardiomyocytes. Compared with chitosan hydrogel, CSVC hydrogel can clearly improve the survival of cardiomyocytes and reduce the ROS level under H2O2-induced oxidative stress conditions. These results suggest that CSVC hydrogel has the potential to support the survival of cardiomyocytes in tissue engineering.
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Yadav N, Gupta N, Singh DP. Ameliorating Effect of Bicarbonate on Salinity Induced Changes in the Growth, Nutrient Status, Cell Constituents and Photosynthetic Attributes of Microalga Chlorella vulgaris. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 108:491-499. [PMID: 33594450 DOI: 10.1007/s00128-021-03135-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
The cells of Chlorella vulgaris exhibited NaCl (0-400 mM) induced decrease in the growth, protein, chlorophyll, carbohydrate and total organic carbon, whereas total lipid and proline content increased with rising level of NaCl. Addition of NaHCO3 (20 mM) exhibited antagonistic effect against the adverse effect of salinity on the growth, level of macromolecules except proline. The SEM-EDS analysis of NaCl treated cells exhibited morphological variations as well as reduced accumulation of Na and Cl due to the presence of NaHCO3. The results on chlorophyll fluorescence induction kinetics revealed NaCl induced decline in the photosynthetic performance and quantum yield, while non-photochemical quenching of chlorophyll was enhanced, particularly at lower concentrations of NaCl. Addition of NaHCO3 to NaCl treated cells exhibited further increase in the non-photochemical quenching values. Thus, these results demonstrated that adverse impact of NaCl on the C. vulgaris cells was significantly mitigated in the presence of bicarbonate.
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Affiliation(s)
- Nisha Yadav
- Department of Environmental Science, BabasahebBhimraoAmbedkar University, VidyaVihar, Raebareli Road, Lucknow, UP, 226025, India
| | - Neha Gupta
- Department of Environmental Science, BabasahebBhimraoAmbedkar University, VidyaVihar, Raebareli Road, Lucknow, UP, 226025, India
| | - D P Singh
- Department of Environmental Science, BabasahebBhimraoAmbedkar University, VidyaVihar, Raebareli Road, Lucknow, UP, 226025, India.
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Panjekobi M, Einali A. Trehalose treatment alters carbon partitioning and reduces the accumulation of individual metabolites but does not affect salt tolerance in the green microalga Dunaliella bardawil. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:2333-2344. [PMID: 34744369 PMCID: PMC8526648 DOI: 10.1007/s12298-021-01078-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/27/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
The effects of trehalose (Tre), a non-reducing disaccharide, on metabolic changes, antioxidant status, and salt tolerance in Dunaliella bardawil cells were investigated. Algal suspensions containing 1, 2, and 3 M NaCl were treated with 5 mM Tre. While the content of pigments, reducing sugars, proteins, glycerol, and ascorbate pool accumulated with increasing salinity, the content of non-reducing sugars, starch, amino acids, proline, hydrogen peroxide, and lipid peroxidation level decreased significantly. Tre-treated cells showed a decrease in pigments content, reducing sugars, starch, proteins, amino acids, proline, glycerol, and the activity of non-specific peroxidase and polyphenol oxidase, but an increase in non-reducing sugars, oxidized ascorbate, and ascorbate peroxidase activity occurred unchanged in the ascorbate pool. However, the density and fresh weight of the cells remained statistically unchanged in all Tre-treated and untreated cultures. These results suggest that D. bardawil cells potentially tolerate different salt levels by accumulating metabolites, whereas Tre treatment changes carbon partitioning and significantly reduces beneficial metabolites without altering salt tolerance. Therefore, the regulation of carbon partitioning rather than the amount of assimilated carbon may play an important role in inducing salinity tolerance of D. bardawil. However, Tre is not able to enhance the salt tolerance of halotolerants and is even economically damaging due to the reduction of unique metabolites such as glycerol and β-carotene.
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Affiliation(s)
- Mahdieh Panjekobi
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Alireza Einali
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
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Moradi Z, Madadkar Haghjou M, Zarei M, Colville L, Raza A. Synergy of production of value-added bioplastic, astaxanthin and phycobilin co-products and Direct Green 6 textile dye remediation in Spirulina platensis. CHEMOSPHERE 2021; 280:130920. [PMID: 34162106 DOI: 10.1016/j.chemosphere.2021.130920] [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: 02/01/2021] [Revised: 05/04/2021] [Accepted: 05/14/2021] [Indexed: 06/13/2023]
Abstract
Phyco-remediation of dyestuffs in textile wastewaters is of economic, industrial, and environmental importance. We evaluated the remediation of the textile dye, Direct Green 6 (DG6), by Spirulina platensis, and investigated the novel possibility that DG6 treatment enhances production of the biopolymer, polyhydroxybutyrate (PHB). We showed that both live and dead cells of Spirulina were capable of DG6 remediation, but live cells could be re-used with no loss of remediation efficiency. Furthermore, DG6 remediation by live cells resulted in increased algal biomass and trichome lengths, and stimulated production of valuable metabolites, including PHB, antioxidants, carbohydrates and pigments (phycobilins and astaxanthin). We determined the optimal conditions for DG6 remediation and an artificial neural network (ANN) accurately modeled the experimental data and predicted the concentration of dye as the most and algal turbidity as the least important parameters for DG6 removal efficiency. A DG6 concentration of 60 mg L-1 resulted in the highest simultaneous co-production of PHB (12.7 ± 1.7% DW) and increase of astaxanthin (194%), carotenoids (50%), phenol (51%), carbohydrates (27%) total phycobilin (43%), together with the enhancement of biomass and trichome lengths (95%). Oxidative stress indices and enzyme activities such as peroxidases and laccase (involved in dye removal/antioxidant functions) were also increased by dye dosage. On the basis of our results, we propose that S. platensis may use DG6 dye as a nitrogen/carbon source for co-accumulation of valuable bioplastic and metabolites.
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Affiliation(s)
- Zahra Moradi
- Department of Biology, Plant Physiology, Faculty of Science, Lorestan University, Khoramabad-Tehran Road (5th K), Iran.
| | - Maryam Madadkar Haghjou
- Department of Biology, Plant Physiology, Faculty of Science, Lorestan University, Khoramabad-Tehran Road (5th K), Iran.
| | - Mahmoud Zarei
- Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Iran.
| | - Louise Colville
- Department of Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK.
| | - Ali Raza
- Key Lab of Biology and Genetic Improvement of Oil Crops, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Wuhan, 430062, China.
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Tamaki S, Mochida K, Suzuki K. Diverse Biosynthetic Pathways and Protective Functions against Environmental Stress of Antioxidants in Microalgae. PLANTS (BASEL, SWITZERLAND) 2021; 10:1250. [PMID: 34205386 PMCID: PMC8234872 DOI: 10.3390/plants10061250] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 01/08/2023]
Abstract
Eukaryotic microalgae have been classified into several biological divisions and have evolutionarily acquired diverse morphologies, metabolisms, and life cycles. They are naturally exposed to environmental stresses that cause oxidative damage due to reactive oxygen species accumulation. To cope with environmental stresses, microalgae contain various antioxidants, including carotenoids, ascorbate (AsA), and glutathione (GSH). Carotenoids are hydrophobic pigments required for light harvesting, photoprotection, and phototaxis. AsA constitutes the AsA-GSH cycle together with GSH and is responsible for photooxidative stress defense. GSH contributes not only to ROS scavenging, but also to heavy metal detoxification and thiol-based redox regulation. The evolutionary diversity of microalgae influences the composition and biosynthetic pathways of these antioxidants. For example, α-carotene and its derivatives are specific to Chlorophyta, whereas diadinoxanthin and fucoxanthin are found in Heterokontophyta, Haptophyta, and Dinophyta. It has been suggested that AsA is biosynthesized via the plant pathway in Chlorophyta and Rhodophyta and via the Euglena pathway in Euglenophyta, Heterokontophyta, and Haptophyta. The GSH biosynthetic pathway is conserved in all biological kingdoms; however, Euglenophyta are able to synthesize an additional thiol antioxidant, trypanothione, using GSH as the substrate. In the present study, we reviewed and discussed the diversity of microalgal antioxidants, including recent findings.
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Affiliation(s)
- Shun Tamaki
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, Yokohama 230-0045, Japan; (K.M.); (K.S.)
| | - Keiichi Mochida
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, Yokohama 230-0045, Japan; (K.M.); (K.S.)
- RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
- Kihara Institute for Biological Research, Yokohama City University, Yokohama 230-0045, Japan
- School of Information and Data Sciences, Nagasaki University, Nagasaki 852-8521, Japan
| | - Kengo Suzuki
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, Yokohama 230-0045, Japan; (K.M.); (K.S.)
- euglena Co., Ltd., Tokyo 108-0014, Japan
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Bahador E, Einali A, Azizian-Shermeh O, Sangtarash MH. Metabolic responses of the green microalga Dunaliella salina to silver nanoparticles-induced oxidative stress in the presence of salicylic acid treatment. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 217:105356. [PMID: 31733504 DOI: 10.1016/j.aquatox.2019.105356] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/02/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
In the present study, the biochemical responses and antioxidant enzymes activity of the Dunaliella salina, a green microalga, to the interaction of silver nanoparticles (AgNPs) and salicylic acid (SA) were investigated. Algal suspensions in the phase of logarithmic growth were subjected to the concentrations of 0, 5, 15, and 25 pM AgNPs with or without 1 mM SA. AgNPs level of 25 pM declined cell division but highly accumulated levels of chlorophyll, β-carotene, proteins, free amino acid, carbohydrates, and hydrogen peroxide, which was associated with enhanced the activity of proteolysis, lipid peroxidation, and antioxidant enzymes. SA-treated cells at 25 pM AgNPs improved cell growth but declined the activities of antioxidant enzymes and proteolytic along with a lower accumulation of metabolites except β-carotene relative to untreated controls. These results suggest that AgNPs treatment induce oxidative stress in D. salina cells, which tolerated by alga through the metabolic modifications and accumulating β-carotene, while SA induces AgNPs tolerance by the mechanisms that direct carbon flux to growth and β-carotene biosynthesis rather than the antioxidant enzymes or osmoprotectant metabolites.
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Affiliation(s)
- Elham Bahador
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Alireza Einali
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran.
| | - Omid Azizian-Shermeh
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
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Ji X, Cheng J, Gong D, Zhao X, Qi Y, Su Y, Ma W. The effect of NaCl stress on photosynthetic efficiency and lipid production in freshwater microalga-Scenedesmus obliquus XJ002. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 633:593-599. [PMID: 29587228 DOI: 10.1016/j.scitotenv.2018.03.240] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/14/2018] [Accepted: 03/20/2018] [Indexed: 05/25/2023]
Abstract
Rapid industrialization and population growth have increased the world's energy demands, resulting in a shortage of conventional fossil fuels. Thus, there is an urgent need to develop sustainable and renewable forms of energy. Microalgae have emerged as a potential feedstock for biofuel production. Under stress conditions, lipid production is enhanced in algal cells due to changes in the lipid biosynthetic pathways that produce neutral lipids. In this study, we examined the physiological and biochemical effects of salinity stress (0.00, 0.01, 0.10, 0.15, 0.20M) on the freshwater microalga Scenedesmus obliquus XJ002. We found that the biomass and the content of chlorophyll a, b and carotenoids decreased with increasing NaCl concentration. NaCl stress damaged the oxygen evolving complex (OEC) and the PSII (photosystem II) reaction center and subsequently suppressed electron transport at the donor and receptor sides of the reaction center, influencing the absorption, transfer, and application of light energy. Additionally, the total lipid content of cells was significantly increased under NaCl stress treatment. The highest lipid content (32.26%) was found in cells cultured in the presence of 0.20M NaCl, which was about 2.52-fold higher than that of cells grown in medium lacking NaCl (12.82%). In addition to providing insight into the physiological and biochemical responses of S. obliquus XJ002 to salinity stress, these findings show that lipid production, and hence biofuel feedstock production, can be boosted by adjusting salt levels in the growth medium.
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Affiliation(s)
- Xiang Ji
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou 014010, China; School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Jie Cheng
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou 014010, China
| | - Donghui Gong
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou 014010, China
| | - Xiujuan Zhao
- School of Life Science and Technology, Inner Mongolia University of Science and Technology, Baotou 014010, China
| | - Yun Qi
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yongning Su
- Inner Mongolia Rejuve Biotech Co. Ltd, Erdos 016100, China
| | - Wenchao Ma
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
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Einali A. The induction of salt stress tolerance by propyl gallate treatment in green microalga Dunaliella bardawil, through enhancing ascorbate pool and antioxidant enzymes activity. PROTOPLASMA 2018; 255:601-611. [PMID: 28990124 DOI: 10.1007/s00709-017-1173-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 10/02/2017] [Indexed: 05/10/2023]
Abstract
The effect of propyl gallate (PG), a synthetic antioxidant, on antioxidant responses and salinity tolerance was investigated in the cells of the green microalga, Dunaliella bardawil. Algal suspensions grown at three salinity levels of 1, 2, and 3 M NaCl were incubated with 1 mM of PG. The number of cells was significantly lower in all PG-treated cells compared to untreated controls. Despite PG-induced cell death, the fresh weight of all PG-treated cells was considerably higher than controls. PG-treated cells had enhanced antioxidant capacity because of increased levels of Chlorophyll a, β-carotene, reduced ascorbate, protein, and enzymatic activities, but accumulated lower levels of malonyldialdehyde and hydrogen peroxide compared to untreated cells. The results suggest that PG acts as a signal molecule both directly by reducing of free radical oxidants and indirectly by augmenting ascorbate pool levels, β-carotene production, and antioxidant enzymes activity to boost the capacity of antioxidant systems and radical oxygen species scavenging. Therefore, induction of salt stress tolerance by PG in D. bardawil is associated with metabolic adjustments through activation or synthesis of both enzymatic and non-enzymatic molecules involved in antioxidant systems.
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Affiliation(s)
- Alireza Einali
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran.
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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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