1
|
Wang P, Li D, Sun M, Yin J, Zheng T. Microalgae enhanced co-metabolism of sulfamethoxazole using aquacultural feedstuff components: Co-metabolic pathways and enzymatic mechanisms. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134279. [PMID: 38613960 DOI: 10.1016/j.jhazmat.2024.134279] [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: 01/23/2024] [Revised: 02/28/2024] [Accepted: 04/09/2024] [Indexed: 04/15/2024]
Abstract
The application of antibiotics in freshwater aquaculture leads to increased contamination of aquatic environments. However, limited information is available on the co-metabolic biodegradation of antibiotics by microalgae in aquaculture. Feedstuffs provide multiple organic substrates for microalgae-mediated co-metabolism. Herein, we investigated the co-metabolism of sulfamethoxazole (SMX) by Chlorella pyrenoidosa when adding main components of feedstuff (glucose and lysine). Results showed that lysine had an approximately 1.5-fold stronger enhancement on microalgae-mediated co-metabolism of SMX than glucose, with the highest removal rate (68.77% ± 0.50%) observed in the 9-mM-Lys co-metabolic system. Furthermore, we incorporated reactive sites predicted by density functional theory calculations, 14 co-metabolites identified by mass spectrometry, and the roles of 18 significantly activated enzymes to reveal the catalytic reaction mechanisms underlying the microalgae-mediated co-metabolism of SMX. In lysine- and glucose-treated groups, five similar co-metabolic pathways were proposed, including bond breaking on the nucleophilic sulfur atom, ring cleavage and hydroxylation at multiple free radical reaction sites, together with acylation and glutamyl conjugation on electrophilic nitrogen atoms. Cytochrome P450, serine hydrolase, and peroxidase play crucial roles in catalyzing hydroxylation, bond breaking, and ring cleavage of SMX. These findings provide theoretical support for better utilization of microalgae-driven co-metabolism to reduce sulfonamide antibiotic residues in aquaculture.
Collapse
Affiliation(s)
- Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| | - Dingxin Li
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| | - Min Sun
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China.
| | - Jinbao Yin
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| | - Tianming Zheng
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| |
Collapse
|
2
|
Yu H, Fu C, Li M, Zong W. Non-negligible inhibition effect of microcystin-LR biodegradation products target to protein phosphatase 2A. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 345:123491. [PMID: 38346637 DOI: 10.1016/j.envpol.2024.123491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/27/2024] [Accepted: 02/01/2024] [Indexed: 02/16/2024]
Abstract
Though biodegradation is an important regulation pathway for microcystins (MCs) pollution, more consideration needs to be given to the potential risk associated with related biodegradation products (MC-BDPs). In this work, typical MCLR-BDPs were prepared and their toxicity was evaluated by protein phosphatases (PPs) inhibition assay. Results showed the initial ring opening of MCLR played a crucial role in detoxification. However, partial MCLR-BDPs still retained the critical structures and thus exhibited certain toxicity (2.8-43.5% of MCLR). With the aid of molecular simulation, the mechanism for the potential toxicity of BDPs targeting PP2A was elucidated. The initial ring opening made the loss of hydrogen bond Leu2←Arg89, and pi-H bond Adda5-His191, which was responsible for the significant reduction in the toxicity of MCLR-BDP. However, the key hydrogen bonds MeAsp3←Arg89, Glu6←Arg89, Adda5←Asn117, Adda5←His118, Arg4→Pro213, Arg4←Arg214, Ala1←Arg268, and Mdha7←Arg268, metal bond Glu6-Mn12+, and ionic bonds Glu6-Arg89, and Glu6-Mn22+ were preserved in varying degrees. Above preserved interactions maintained the interactions between PP2A and Mn2+ ions (reducing the exposure of Mn2+ ions). Above preserved interactions also hindered the combination of phosphate groups to Arg214 residual and thus exhibited potential toxicity.
Collapse
Affiliation(s)
- Huiqun Yu
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, Shandong 250014, China.
| | - Chunyu Fu
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, Shandong 250014, China.
| | - Mengchen Li
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, Shandong 250014, China.
| | - Wansong Zong
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, Shandong 250014, China.
| |
Collapse
|
3
|
Yu B, Zhang Y, Wu H, Yan W, Meng Y, Hu C, Liu Z, Ding J, Zhang H. Advanced oxidation processes for synchronizing harmful microcystis blooms control with algal metabolites removal: From the laboratory to practical applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167650. [PMID: 37806585 DOI: 10.1016/j.scitotenv.2023.167650] [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: 07/30/2023] [Revised: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Harmful algal blooms (HABs) in freshwater systems have become a global epidemic, leading to a series of problems related to cyanobacterial outbreaks and toxicity. Studies are needed to improve the technology used for the simultaneous removal of harmful cyanobacteria and algal metabolites. In this review, widely reported advanced oxidation processes (AOPs) strategies for removing major species Microcystis aeruginosa (M. aeruginosa) and microcystins (MCs) were screened through bibliometrics, such as photocatalysis, activated persulfate, H2O2, Ozone oxidation, ultrasonic oxidation, and electrochemical oxidation, etc. AOPs generate kinds of reactive oxygen species (ROS) to inactivate cyanobacteria and degrade cyanotoxins. A series of responses occurs in algal cells to resist the damaging effects of ROS generated by AOPs. Specifically, we reviewed laboratory research, mechanisms, practical applications, and challenges of HABs treatments in AOPs. Problems common to these technologies include the impact of algal response and metabolites, and environmental factors. This information provides guidance for future research on the removal of harmful cyanobacteria and treatment of algal metabolites using AOPs.
Collapse
Affiliation(s)
- Bingzhi Yu
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Yinan Zhang
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Huazhen Wu
- Hangzhou Huanke Environmental Consulting Co. LTD, 310010 Hangzhou, Zhejiang, China
| | - Wen Yan
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Yunjuan Meng
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Chao Hu
- School of Life and Environmental Sciences, Hangzhou Normal University, 311121 Hangzhou, Zhejiang, China
| | - Zhiquan Liu
- School of Engineering, Hangzhou Normal University, 310018 Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, 311121 Hangzhou, Zhejiang, China
| | - Jiafeng Ding
- School of Engineering, Hangzhou Normal University, 310018 Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, 311121 Hangzhou, Zhejiang, China.
| | - Hangjun Zhang
- School of Engineering, Hangzhou Normal University, 310018 Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, 311121 Hangzhou, Zhejiang, China
| |
Collapse
|
4
|
Silva TT, Jacinavicius FR, Pinto E, Borrely SI. Intracellular microcystins degradation and acute toxicity decrease towards Daphnia similis by low electron-beam irradiation doses. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.103086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|
5
|
Yu H, Cui J, Xu Y, Feng LJ, Zong W. Regulation Effectiveness and Mechanism of Biotransformation Pathway on the Toxicity of Microcystin-LR Target to Protein Phosphatase 2A. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:964. [PMID: 36673721 PMCID: PMC9859369 DOI: 10.3390/ijerph20020964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 12/29/2022] [Accepted: 12/31/2022] [Indexed: 06/17/2023]
Abstract
Biotransformation is recognized as a potential pathway to regulate the environmental risk of microcystins (MCs). To explore the regulation effectiveness and mechanism of the biotransformation pathway, six typical MCLR-biotransformation products (MCLR-BTPs) were prepared, and their inhibition effects on protein phosphatase 2A (PP2A) were evaluated. The inhibition effects of the MCLR-BTPs generally decreased with the increase in biothiol molecular weights and polarity, indicating that biotransformation was an effective pathway through which to regulate MCLR toxicity. To further explore the regulation mechanism, the key interaction processes between the MCLR/MCLR-BTPs and the PP2A were explored by homology modeling and molecular docking. The introduced biothiols blocked the covalent binding of Mdha7 to Cys269 but strengthened the hydrogen bond "Mdha7"→Arg268. The changed "Mdha7" intervened the combination of MCLR-BTPs to PP2A by weakening the hydrogen bonds Arg4←Arg214, Arg4→Pro213, Adda5←His118, and Ala1←Arg268, and the ionic bond Glu6-Mn12+. The weakening combination of the MCLR-BTPs to PP2A further attenuated the interactions between the conserved domain and the Mn2+ ions (including the ionic bonds Asp57-Mn12+ and Asp85-Mn12+ and the metal bonds Asp57-Mn12+ and Asn117-Mn12+) and increased the exposure of the Mn2+ ions. Meanwhile, the weakened hydrogen bond Arg4←Arg214 facilitated the combination of the phosphate group to Arg214 (with increased exposure). In this way, the catalytic activity of the PP2A was restored.
Collapse
Affiliation(s)
| | | | | | - Li-Juan Feng
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan 250014, China
| | - Wansong Zong
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan 250014, China
| |
Collapse
|
6
|
Yu H, Xu Y, Cui J, Zong W. Mechanism for the Potential Inhibition Effect of Microcystin-LR Disinfectant By-Products on Protein Phosphatase 2A. Toxins (Basel) 2022; 14:toxins14120878. [PMID: 36548775 PMCID: PMC9780900 DOI: 10.3390/toxins14120878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
The secondary contamination of microcystin disinfection by-products (MC-DBPs) is of concern due to the residual structure similar to their original toxin. Based on identification and preparation, the potential inhibition effect of typical MCLR-DBPs (associated with the oxidation of Adda5) on PP2A was confirmed in the sequence of MCLR > P1 > P4 > P3 ≈ P2 > P7 ≈ P6 ≈ P5 > P8. To elucidate the molecular mechanism underlying the inhibition effect, the interaction models for typical MCLR-DBPs and PP2A were constructed using a modeling-based-on-ligand-similarity approach, and the candidate interaction parameters between typical MCLR-DBPs and PP2A were obtained by molecular docking. By analyzing the correlation between inhibition data and candidate interaction parameters, the key interaction parameters were filtered as hydrogen bonds "Adda5"←Asn117, "Adda5"←His118, MeAsp3←Arg89, Arg4←Arg214, Arg4→Pro213; ionic bonds Glu6-Arg89, Asp85-Mn12+, Asp57-Mn22+; and metal bonds Glu6-Mn12+, Glu6-Mn22+. With the gradual intensification of chlorination, Adda5 was destroyed to varying degrees. The key interactions changed correspondingly, resulting in the discrepant inhibition effects of typical MCLR-DBPs on PP2A.
Collapse
|
7
|
Ma X, Chen J, Liu B, Huang Y, Tang Y, Wei Q. Removal of Microcystis aeruginosa and microcystin-LR by UV/Fenton system: characteristics and degradation pathways. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
8
|
Almuhtaram H, Hofmann R. Evaluation of ultraviolet/peracetic acid to degrade M. aeruginosa and microcystins -LR and -RR. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127357. [PMID: 34687995 DOI: 10.1016/j.jhazmat.2021.127357] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
The reactivity of peracetic acid (PAA) alone, and PAA exposed to ultraviolet radiation (UV), was investigated on Microcystis aeruginosa cells, and on microcystin-LR and -RR. Reaction rates between PAA and MC-LR (k = 3.46 M-1 s-1) and MC-RR (k = 2.67 M-1 s-1) were determined in an unbuffered acidic solution, and they are approximately 35-45 times lower than a previously reported reaction rate between MC-LR and chlorine at pH 6. Peracetic acid reacted with M. aeruginosa cells as a function of PAA and cell concentrations, with 10 mg/L PAA resulting in 1-log reduction of total MC-LR within 15 min. Advanced oxidation by UV/PAA readily degraded MC-LR and MC-RR, outperforming UV/H2O2 at pH 7.7 by > 50% on an equimolar basis. Indirect photolysis at this pH is due to •OH and organic radicals, as determined by trials in the presence of excess tert-butanol to scavenge •OH. The process is less effective when the pH departs from neutral conditions (5.9 or 10.6) due to the decreased effects of both radicals. These findings suggest that PAA alone might be a viable option for cyanobacteria and microcystins control in preoxidation applications and that UV/PAA is an effective process for degrading MC-LR and MC-RR at neutral pH.
Collapse
Affiliation(s)
- Husein Almuhtaram
- Department of Civil and Mineral Engineering, University of Toronto, Toronto, ON M5S 1A4, Canada.
| | - Ron Hofmann
- Department of Civil and Mineral Engineering, University of Toronto, Toronto, ON M5S 1A4, Canada
| |
Collapse
|
9
|
Folcik AM, Klemashevich C, Pillai SD. Response of Microcystis aeruginosa and Microcystin-LR to electron beam irradiation doses. Radiat Phys Chem Oxf Engl 1993 2021; 186:109534. [PMID: 34040287 PMCID: PMC8143040 DOI: 10.1016/j.radphyschem.2021.109534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Harmful cyanobacterial blooms (cyanoHABs) pose threats to human and animal health due to the production of harmful cyanotoxins. Microcystis aeruginosa is a common cyanobacterium associated with these blooms and is responsible for producing the potent cyclic hepatotoxin microcystin-LR (MC-LR). Concerns over the public health implications of these toxins in water supplies have increased due to rising occurrence of these blooms. High energy electron beam (eBeam) irradiation technology presents a promising strategy for the mitigation of both cyanobacterial cells and cyanotoxins within the water treatment process. However, it is imperative that both cellular and chemical responses to eBeam irradiation are understood to ensure efficient treatment. We sought to investigate the effect of eBeam irradiation on M. aeruginosa cells and MC-LR degradation. Results indicate that doses as low as 2 kGy are lethal to M. aeruginosa cells and induce cell lysis. Even lower doses are required for degradation of the parent MC-LR toxin. However, it was observed that there is a delay in cell lysis after irradiation where M. aeruginosa cells may still be metabolically active and able to synthesize microcystin. These results suggest that eBeam may be suitable for cyanoHAB mitigation in water treatment if employed following cell lysis.
Collapse
Affiliation(s)
- Alexandra M. Folcik
- Interdisciplinary Graduate Program in Toxicology, Texas A&M University, College Station, TX, USA
- National Center for Electron Beam Research, An IAEA Collaborating Centre for Electron Beam Technology, Texas A&M University, College Station, TX, USA
| | - Cory Klemashevich
- Integrated Metabolomic Analysis Core, Texas A&M University, College Station, TX, USA
| | - Suresh D. Pillai
- Interdisciplinary Graduate Program in Toxicology, Texas A&M University, College Station, TX, USA
- National Center for Electron Beam Research, An IAEA Collaborating Centre for Electron Beam Technology, Texas A&M University, College Station, TX, USA
| |
Collapse
|
10
|
Hu Z, Wang X, Zhang S, Zong W. Research on the discrepant inhibition mechanism of microcystin-LR disinfectant by-products target to protein phosphatase 1. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:45586-45595. [PMID: 33871773 DOI: 10.1007/s11356-021-12472-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
The secondary contamination for microcystin disinfection by-products (MC-DBPs) is of concern due to the residual toxic structure similar to their original toxins. To evaluate the toxicity of MC-DBPs, the discrepant inhibition mechanisms target to protein phosphatase 1 (PP1) were evaluated. Five typical MCLR-DBPs related to the oxidation of Adda5 were identified as C49H75N10O13Cl (+1Cl1OH, P1/P2), C34H54N10O12 (+2OH, P3/P4), and C49H76N10O14 (P5). Toxicity inhibition experiment on PP1 showed that the toxicity was in the sequence of MCLR > P3 > P1 > P4 > P2 > P5. Base on MOE molecular simulation, the discrepant inhibition mechanisms for MCLR and MCLR-DBPs target to PP1 were further clarified. The combination of MCLR/MCLR-DBPs to PP1 was mainly restrained by residues Adda5 and Arg4. Above key sites promoted the binding of MCLR/MCLR-DBPs to PP1 through the hydrogen bonds (H2O ← Adda5, Tyr134 → Adda5, H2O ← Arg4, Tyr134 → Arg4, Glu275 ← Arg4), ionic bonds (Asp197-Adda5, Glu275-Arg4, Asp220 → Arg4), and H-pi bonds (Trp206 ↔ Adda5, Ser129 ↔ Adda5). The oxidation of Adda5 also affected Mdha7 participated ionic bond Glu275-Mdha7 and Glu6 participated hydrogen bond H2O → Glu6. Besides, the "integral hydrogen bonds and ionic bonds" between toxin and PP1 also had important effects on the toxin toxicity. In this way, the inhibition of "Adda5 destroyed" MC-DBPs target to PP1 was regulated.
Collapse
Affiliation(s)
- Zhengxin Hu
- College of Geography and Environment, Shandong Normal University, 1# Daxue Road, Jinan, 250358, Shandong, China
| | - Xiaoning Wang
- College of Geography and Environment, Shandong Normal University, 1# Daxue Road, Jinan, 250358, Shandong, China
| | - Shuhan Zhang
- College of Geography and Environment, Shandong Normal University, 1# Daxue Road, Jinan, 250358, Shandong, China
| | - Wansong Zong
- College of Geography and Environment, Shandong Normal University, 1# Daxue Road, Jinan, 250358, Shandong, China.
| |
Collapse
|
11
|
Munoz M, Cirés S, de Pedro ZM, Colina JÁ, Velásquez-Figueroa Y, Carmona-Jiménez J, Caro-Borrero A, Salazar A, Santa María Fuster MC, Contreras D, Perona E, Quesada A, Casas JA. Overview of toxic cyanobacteria and cyanotoxins in Ibero-American freshwaters: Challenges for risk management and opportunities for removal by advanced technologies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143197. [PMID: 33160675 DOI: 10.1016/j.scitotenv.2020.143197] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/04/2020] [Accepted: 10/16/2020] [Indexed: 06/11/2023]
Abstract
The increasing occurrence of cyanobacterial blooms worldwide represents an important threat for both the environment and public health. In this context, the development of risk analysis and management tools as well as sustainable and cost-effective treatment processes is essential. The research project TALGENTOX, funded by the Ibero-American Science and Technology Program for Development (CYTED-2019), aims to address this ambitious challenge in countries with different environmental and social conditions within the Ibero-American context. It is based on a multidisciplinary approach that combines ecology, water management and technology fields, and includes research groups from Chile, Colombia, Mexico, Peru and Spain. In this review, the occurrence of toxic cyanobacteria and cyanotoxins in freshwaters from these countries are summarized. The presence of cyanotoxins has been confirmed in all countries but the information is still scarce and further monitoring is required. In this regard, remote sensing or metagenomics are good alternatives at reasonable cost. The risk management of freshwaters from those countries considering the most frequent uses (consumption and recreation) has been also evaluated. Only Spain and Peru include cyanotoxins in its drinking water legislation (only MC-LR) and thus, there is a need for regulatory improvements. The development of preventive strategies like diminishing nutrient loads to aquatic systems is also required. In the same line, corrective measures are urgently needed especially in drinking waters. Advanced Oxidation Processes (AOPs) have the potential to play a major role in this scenario as they are effective for the elimination of most cyanotoxins classes. The research on the field of AOPs is herein summarized considering the cost-effectiveness, environmental character and technical applicability of such technologies. Fenton-based processes and photocatalysis using solar irradiation or LED light represent very promising alternatives given their high cost-efficiency. Further research should focus on developing stable long-term operation systems, addressing their scale-up.
Collapse
Affiliation(s)
- Macarena Munoz
- Departamento de Ingeniería Química, Universidad Autónoma de Madrid, Madrid, Spain.
| | - Samuel Cirés
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain.
| | - Zahara M de Pedro
- Departamento de Ingeniería Química, Universidad Autónoma de Madrid, Madrid, Spain
| | - José Ángel Colina
- Departamento de Ingeniería Química, Universidad de Cartagena, Cartagena de Indias, Colombia
| | | | - Javier Carmona-Jiménez
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Angela Caro-Borrero
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Anthony Salazar
- Centro de Investigación y Tecnología de Agua - CITA, Universidad de Ingeniería y Tecnología - UTEC, Lima, Peru
| | | | - David Contreras
- Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
| | - Elvira Perona
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | - Antonio Quesada
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jose A Casas
- Departamento de Ingeniería Química, Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
12
|
Kurtz T, Zeng T, Rosario-Ortiz FL. Photodegradation of cyanotoxins in surface waters. WATER RESEARCH 2021; 192:116804. [PMID: 33494040 DOI: 10.1016/j.watres.2021.116804] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/15/2020] [Accepted: 12/31/2020] [Indexed: 06/12/2023]
Abstract
Cyanotoxin-producing harmful algal blooms (HABs) are a global occurrence and pose ecotoxicological threats to humans and animals alike. The presence of cyanotoxins can seriously harm or kill nearby wildlife and restrict a body of water's use as a drinking water supply and recreational site, making it imperative to fully understand their fate and transport in natural waters. Photodegradation contributes to the overall degradation of cyanotoxins in environmental systems, especially for those present in the photic zone of surface waters. This makes photochemical transformation mechanisms important factors to account for when assessing the persistence of cyanotoxins in environmental systems. This paper reviews current knowledge on the photodegradation rates and pathways of cyanotoxins that can occur over the course of HABs. Sensitized, or indirect, photolysis contributes to the degradation of all cyanotoxins addressed in this paper (anatoxins, cylindrospermopsins, domoic acids, microcystins, and nodularins), with hydroxyl radicals (•OH), excited triplet states formed from the absorption of light by dissolved organic matter (3DOM*), and photosynthetic pigment sensitized pathways being of primary interest. Direct photolysis pathways play a less significant role, but are still relevant for most of the cyanotoxins discussed in this paper.
Collapse
Affiliation(s)
- Tyler Kurtz
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Colorado 80309, United States; Environmental Engineering Program, University of Colorado Boulder, Colorado 80309, United States
| | - Teng Zeng
- Department of Civil and Environmental Engineering, 151 Link Hall, Syracuse University, Syracuse, NY 13244, United States
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Colorado 80309, United States; Environmental Engineering Program, University of Colorado Boulder, Colorado 80309, United States.
| |
Collapse
|
13
|
Aragão MC, Dos Reis KC, Rocha MAM, de Oliveira Guedes D, Dos Santos EC, Capelo-Neto J. Removal of Dolichospermum circinale, Microcystis aeruginosa, and their metabolites using hydrogen peroxide and visible light. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 232:105735. [PMID: 33540290 DOI: 10.1016/j.aquatox.2020.105735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/06/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
Frequent cyanobacterial blooms in reservoirs used for human supply increase the risk of noxious secondary metabolites, endangering human health and ecological balance, and requiring constant monitoring by water companies. Although hydrogen peroxide (H2O2) has been widely reported as an effective agent for the control of cyanobacteria, being Microcystis aeruginosa one of the most studied species, very limited data is available on its effects over Dolichospermum circinale. Therefore, this study aimed to evaluate the impact of H2O2 on D. circinale and comparing it to the effects over the M. aeruginosa. The treatment was performed in cyanobacterial cultures with the application of 2 and 5 mg L-1 of H2O2 under visible light. To measure the impact of the treatment, intact cells were counted and cell re-growth monitored. Geosmin and microcystin, cell pigments, color, and organic matter in water were also analyzed during the treatment. The results showed that even the smallest H2O2 concentration (2 mg L-1) was able to completely remove D. circinale cells. Although M. aeruginosa could only be completely removed using 5 mg L-1, the few cells remaining after the application of 2 mg L-1 were not viable and did not re-grew after 15 days. Total microcystin concentration increased after M. aeruginosa was exposed to H2O2, suggesting that oxidative stress may increase the detection of this metabolite when the cells are lysed. While 2 mg L-1 was able to significantly decrease total geosmin, the addition of 5 mg L-1 did not improve removal. Chlorophyll-a was readily degraded after cell rupture but the same did not happen to phycocyanin, demonstrating its high resilience to this oxidant. Color and organic matter increased for the M. aeruginosa but decreased for the D. circinale suspension, probably because the higher concentration of the M. aeruginosa yielded more extracellular content to the water which was not able to be degraded by the amount of H2O2 applied.
Collapse
Affiliation(s)
- Marianna Correia Aragão
- Federal University of Ceara, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil.
| | - Kelly Cristina Dos Reis
- Federal University of Ceara, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil.
| | - Maria Aparecida Melo Rocha
- Federal University of Ceara, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil.
| | - Dayvson de Oliveira Guedes
- Federal University of Ceara, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil.
| | - Eduardo Costa Dos Santos
- Federal University of Ceara, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil.
| | - Jose Capelo-Neto
- Federal University of Ceara, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil.
| |
Collapse
|
14
|
Ren L, Hu Z, Wang Q, Du Y, Zong W. Regulation Efficacy and Mechanism of the Toxicity of Microcystin-LR Targeting Protein Phosphatase 1 via the Biodegradation Pathway. Toxins (Basel) 2020; 12:toxins12120790. [PMID: 33322407 PMCID: PMC7764552 DOI: 10.3390/toxins12120790] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 11/16/2022] Open
Abstract
Biodegradation is important to regulate the toxicity and environmental risk of microcystins (MCs). To explore their regulation effectiveness and mechanism, typical biodegradation products originating from microcystin-LR (MCLR) were prepared and purified. The protein phosphatase 1 (PP1) inhibition experiment showed the biodegradation pathway was effective in regulating the toxicity of the biodegradation products by extending the biodegradation. With the assistance of molecular docking, the specific interaction between the toxins and PP1 was explored. The MCLR/MCLR biodegradation products combined with PP1 mainly by the aid of interactions related to the active sites Adda5, Glu6, Mdha7, and the ionic bonds/hydrogen bonds between the integral toxin and PP1. As a consequence, the interactions between Mn22+ and Asp64/Asp92 in the catalytic center were inhibited to varying degrees, resulting in the reduced toxicity of the biodegradation products. During the biodegradation process, the relevant key interactions might be weakened or even disappear, and thus the toxicity was regulated. It is worth noting that the secondary pollution of the partial products (especially for Adda5-Glu6-Mdha7-Ala1 and the linearized MCLR), which still possessed the major active sites, is of deep concern.
Collapse
|
15
|
Frame HC, Somasundar Y, Warner GR, Ryabov AD, Collins TJ. Kinetics of catalytic oxidation of the potent aquatic toxin microcystin-LR by latest generation TAML activators. J COORD CHEM 2020. [DOI: 10.1080/00958972.2020.1840562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Hannah C. Frame
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Yogesh Somasundar
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Genoa R. Warner
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA
- Department of Comparative Biosciences, University of Illinois, Urbana, IL, USA
| | | | | |
Collapse
|
16
|
Micheletto J, de Torres MA, de Paula VDCS, Cerutti VE, Pagioro TA, Cass QB, Martins LRR, de Liz MV, de Freitas AM. The solar photo-Fenton process at neutral pH applied to microcystin-LR degradation: Fe 2+, H 2O 2 and reaction matrix effects. Photochem Photobiol Sci 2020; 19:1078-1087. [PMID: 32618316 DOI: 10.1039/d0pp00050g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Microcystins are a group of cyanotoxins with known hepatotoxic effects, and their presence in drinking water represents a public health concern all over the world. The main objective of this work was to evaluate the solar photo-Fenton process at near-neutral pH in the degradation of microcystin-LR (MC-LR) under conditions close to those found in bloom episodes, with a high concentration of cell debris and natural organic matter (NOM). The influence of experimental parameters such as Fe2+ and H2O2 concentrations, reaction matrix, and the presence of scavenger ions, as well as ecotoxicity before and after treatment, was also evaluated. The reaction matrix was obtained from Microcystis aeruginosa cultivated in ASM-1 medium (ACE1 and ACE2 extracts). H2O2 and Fe2+ concentrations were optimized by 22 factorial design with the central point in a bench-scale solar reactor, using ACE1 extract, and the improved condition was applied in a compound parabolic collector (CPC) reactor, for the ACE2, natural water (RVW) and natural water with M. aeruginosa crude extract (RVCE). Matrix effect assays indicated that radical scavengers present in the medium were responsible for the decrease in the mineralization rates. The solar photo-Fenton process in the CPC reactor achieved COD (75%) and MC-LR (70%) reduction after 120 min at pH = 7.8, [H2O2]/COD = 3.18 and [H2O2]/[Fe2+] = 10 for the ACE2 sample. When the same conditions were applied to the RVCE sample, the process removed 77% of DOC and up to 99% of MC-LR after 45 min of the reaction. Sinapis alba bioassays showed that there was no increase in ecotoxicity after the solar photo-Fenton treatment. These results demonstrate the potential of the solar photo-Fenton process at neutral pH as an additional step in the treatment of natural matrices contaminated with microcystins. In addition, the work reinforces the importance of bioassays in treatment process monitoring.
Collapse
Affiliation(s)
| | | | | | - Vânia Eloiza Cerutti
- Department of Chemistry and Biology, Federal University of Technology - Paraná, Curitiba, Brazil
| | - Thomaz Aurélio Pagioro
- Department of Chemistry and Biology, Federal University of Technology - Paraná, Curitiba, Brazil
| | - Quezia Bezerra Cass
- Department of Chemistry, Federal University of Sao Carlos, Sao Carlos, Sao Paulo, Brazil
| | - Lucia Regina R Martins
- Department of Chemistry and Biology, Federal University of Technology - Paraná, Curitiba, Brazil
| | - Marcus Vinicius de Liz
- Department of Chemistry and Biology, Federal University of Technology - Paraná, Curitiba, Brazil
| | | |
Collapse
|
17
|
Jafari N, Ebrahimpour K, Abdolahnejad A, Karimi M, Ebrahimi A. Efficient degradation of microcystin-LR by BiVO 4/TiO 2 photocatalytic nanocomposite under visible light. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2019; 17:1171-1183. [PMID: 32030183 PMCID: PMC6985378 DOI: 10.1007/s40201-019-00432-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 12/23/2019] [Indexed: 05/23/2023]
Abstract
Microcystin-Leucine Arginine (MC-LR) is one of the most studied cyanotoxins due to its toxicity and abundant that cause health hazards for humans through of the drinking water. In this study, BiVO4/TiO2 nanocomposite was synthesized by hydrothermal method and employed for the removal of MC-LR. The characteristics of the catalysts were determined by FESEM, XRD and FTIR spectra. Response surface methodology (RSM) was applied to assess the effects of operating variables (pH, contact time, and catalyst dose) on the MC-LR removal. The coefficient of determination (R2) was calculated 98.7% for the response. The residual concentration of MC-LR was measured by high-performance liquid chromatography (HPLC). The results show that the highest removal efficiency of MC-LR was 98% under the optimum conditions (pH = 5, contact time = 90 min, and catalyst dose = 0.5 g/l). MC-LR decomposition efficiency by BiVO4/TiO2 nanocomposite was enhanced by pH reduction and increasing of contact time and catalyst dose. The prepared BiVO4/TiO2 nanocomposite with technological potential can be used directly in environmental preservation, specifically in the decontamination of MC-LR from aqueous solutions.
Collapse
Affiliation(s)
- Negar Jafari
- Student Research Committee, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Karim Ebrahimpour
- Environment Research Center, Research Institute for Primordial Prevention of Non-communicable disease, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ali Abdolahnejad
- Environment Research Center, Research Institute for Primordial Prevention of Non-communicable disease, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mahbobe Karimi
- Department of Chemistry, University of Isfahan, Isfahan, Iran
| | - Afshin Ebrahimi
- Environment Research Center, Research Institute for Primordial Prevention of Non-communicable disease, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
18
|
León C, Boix C, Beltrán E, Peñuela G, López F, Sancho JV, Hernández F. Study of cyanotoxin degradation and evaluation of their transformation products in surface waters by LC-QTOF MS. CHEMOSPHERE 2019; 229:538-548. [PMID: 31100625 DOI: 10.1016/j.chemosphere.2019.04.219] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 04/26/2019] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
In the present work, the degradation of three cyanotoxins from the hepatotoxins group was investigated under laboratory-controlled experiments in water samples. Surface waters spiked with microcystin-LR (MC-LR), nodularin (NOD) and cylindrospermopsin (CYN) were subjected to hydrolysis, chlorination and photo-degradation, under both sunlight (SL) and ultraviolet (UV) radiation. A total of 12 transformation products (TPs) were detected and tentatively identified by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF MS). These comprised: 6 chlorination TPs (3 from CYN and 3 from MC-LR, 2 isomers); 4 UV TPs (all from CYN); and 2 sunlight TPs (one isomer from MC-LR and another from NOD). No TPs were observed under hydrolysis conditions. The chemical structures for all TPs were tentatively proposed based on the accurate-mass QTOF MS full-spectra. Analysis of real-world samples collected from the Peñol reservoir (Antioquia, Colombia) revealed the presence of MC-LR and CYN as well as a sunlight TP identified in the laboratory experiments. Data presented in this article will assist further research on TPs potentially formed in future tertiary degradation processes applied for the removal of organic micro-pollutants in water; as well as improving available knowledge on the toxic implications of cyanobacterial toxins TPs in surface waters.
Collapse
Affiliation(s)
- Cristina León
- Grupo Diagnóstico y Control de La Contaminación (GDCON), Facultad de Ingeniería Universidad de Antioquia, Medellín, Colombia.
| | - Clara Boix
- Research Institute for Pesticides and Water (IUPA), University Jaume I. Avda, Sos Baynat, E-12071 Castellon, Spain
| | - Eduardo Beltrán
- Research Institute for Pesticides and Water (IUPA), University Jaume I. Avda, Sos Baynat, E-12071 Castellon, Spain
| | - Gustavo Peñuela
- Grupo Diagnóstico y Control de La Contaminación (GDCON), Facultad de Ingeniería Universidad de Antioquia, Medellín, Colombia
| | - Francisco López
- Research Institute for Pesticides and Water (IUPA), University Jaume I. Avda, Sos Baynat, E-12071 Castellon, Spain
| | - Juan V Sancho
- Research Institute for Pesticides and Water (IUPA), University Jaume I. Avda, Sos Baynat, E-12071 Castellon, Spain
| | - Félix Hernández
- Research Institute for Pesticides and Water (IUPA), University Jaume I. Avda, Sos Baynat, E-12071 Castellon, Spain.
| |
Collapse
|
19
|
Wan Y, Xie P, Wang Z, Ding J, Wang J, Wang S, Wiesner MR. Comparative study on the pretreatment of algae-laden water by UV/persulfate, UV/chlorine, and UV/H 2O 2: Variation of characteristics and alleviation of ultrafiltration membrane fouling. WATER RESEARCH 2019; 158:213-226. [PMID: 31035198 DOI: 10.1016/j.watres.2019.04.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/10/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
In this study, ultraviolet based advanced oxidation processes (UV-AOPs) including UV/persulfate (UV/PS), UV/chlorine, and UV/H2O2 were employed to alleviate ultrafiltration membrane fouling during the treatment of algae-laden water. The results show that UV/PS pretreatment exhibited the best performance on fouling control, followed by the UV/H2O2 pretreatment. The fouling mitigation performance improved with the increase of oxidant dose. However, UV/chlorine pretreatment aggravated membrane fouling, and the irreversible fouling resistance increased by five times compared with that of raw water. The dissolved organic carbon (DOC) in the algae-laden solution was reduced after UV/PS pretreatment, while either UV/chlorine or UV/H2O2 pretreatment had little influence on the DOC of feed water. UV/PS and UV/H2O2 pretreatments were effective in the degradation of fluorescent compounds, thus reducing the deposition of organic matter on the membrane surface. Additionally, the decreased concentration of hydrophobic organics, algal cells, and debris in feed water after UV/PS pretreatment was also contributed to the fouling alleviation. The aggravated irreversible fouling after UV/chlorine pretreatment was probably ascribed to the increased accumulation of hydrophobic fractions in the membrane pores. Modeling result indicates that membrane fouling during the filtration of raw algae-laden water was dominated by intermediate blocking and cake filtration mechanisms. Both UV/PS and UV/H2O2 pretreatments transformed the combined fouling mechanism into standard blocking, while UV/chlorine pretreatment aggravated the pore blocking in the initial filtration period.
Collapse
Affiliation(s)
- Ying Wan
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China
| | - Pengchao Xie
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China; Center for the Environmental Implications of Nanotechnology (CEINT), Duke University, Durham, 27708-0287, USA.
| | - Zongping Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China.
| | - Jiaqi Ding
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China
| | - Jingwen Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China
| | - Songlin Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan, 430074, China
| | - Mark R Wiesner
- Center for the Environmental Implications of Nanotechnology (CEINT), Duke University, Durham, 27708-0287, USA
| |
Collapse
|
20
|
Wang Q, Wang X, Zhang S, Zong W. Molecular mechanism for the discrepant inhibition of microcystins on protein phosphatase 1. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:21774-21783. [PMID: 31134550 DOI: 10.1007/s11356-019-05520-4] [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: 02/09/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Due to variable amino acid residues at positions 2 and 4, microcystins (MCs) had diversified variants with different toxicities. To evaluate the discrepant toxicity, the inhibition effects of five typical MC variants (with the changed amino acid residues at position 4) target to PP1 were evaluated. The inhibition sequence was verified as follows: MCLR (IC50 = 2.6 μg/L) > MCLF (IC50 = 4.4 μg/L) > MCLA (IC50 = 5.5 μg/L) > MCLY (IC50 = 7.9 μg/L) > MCLW (IC50 = 13.6 μg/L). To further clarify the inhibition mechanism for variant toxicity, the interactions between MCs and PP1 were evaluated with the assistance of MOE molecule simulation. Results show the hydrophobic interaction (Adda5 with PP1) and the hydrogen bonds (especially for Z4 → Glu275) were positively correlated with MC toxicity, while the hydrogen bonds (Leu2 ← Arg96, IsoAsp3 ← Arg96, and IsoAsp3 ← Tyr134) and the ion bonds (between Mn2+ and His173/Asn124/Asp92) were negatively correlated with toxicity. However, the hydrogen bonds (Ala1 → Glu275, Mdha7 ← Gly274, Z4 ← Arg221, and Adda5 ← His125), the covalent combination (between Mdha7 and Cys273), and the ion bonds (between Mn2+ and His248/Asp64/His66) were weakly correlated with toxicity. By further analysis, the steric hindrance and hydrophobicity introduced by different Z4 residues affected the changes for combination area and energy of MC-PP1 complexes, leading to the discrepancies in MC toxicity.
Collapse
Affiliation(s)
- Qian Wang
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China
| | - Xiaoning Wang
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China
| | - Shuhan Zhang
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China
| | - Wansong Zong
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China.
| |
Collapse
|
21
|
Zeng G, Zhang M, Wang P, Li X, Wu P, Sun D. Genotoxicity effects of Phanerochaete chrysosporium against harmful algal bloom species by micronucleus test and comet assay. CHEMOSPHERE 2019; 218:1031-1041. [PMID: 30609482 DOI: 10.1016/j.chemosphere.2018.11.148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/20/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
Algal blooms and toxins have become serious ecological problems. White-rot fungi have been demonstrated to be a feasible means of control, but the genotoxicity mechanisms involved have not been reported. In this study, Cryptomonas obovata FACHB-1301, Oscillatoria sp. FACHB-1083, and Scenedesmus quadricauda FACHB-507 were co-cultured with Phanerochaete chrysosporium under optimal conditions of 250 mg-l at 25 °C with DO 7.0 mg-l for 1, 3, 5 and 7 d. Compared to the control groups, the values for tadpoles exposed to algae treated with Phanerochaete chrysosporium were only increased from 1.95 ± 0.09, 2.78 ± 0.08 and 2.37 ± 0.13 to 2.45 ± 0.07, 3.56 ± 0.08 and 2.54 ± 0.10, and the frequency of nuclear anomalies reached 6.45 ± 0.06, 11.14 ± 0.05 and 7.85 ± 0.10 to 7.68 ± 0.08, 13.12 ± 0.06 and 8.57 ± 0.12 in the experimental groups after 7 d. What's more, the tail lengths were only increased to 36.77 ± 0.54, 41.58 ± 0.78 and 35.38 ± 0.66, and the comet length reached 55.67 ± 0.68, 68.56 ± 0.85 and 51.43 ± 0.82. The results demonstrated that Phanerochaete chrysosporium effectively decreased genotoxicity effects in Fejervarya multistriat tadpoles. These results could provide new ideas for inhibiting water blooms, and lay a theoretical foundation for promoting the deepening of water eutrophication.
Collapse
Affiliation(s)
- Guoming Zeng
- Chongqing University of Science and Technology, Chong Qing, 401331, PR China.
| | - Maolan Zhang
- Sichuan University of Science and Engineering, Si Chuan, 643000, PR China.
| | - Pu Wang
- Chongqing University, Chong Qing, 400044, PR China
| | - Xiang Li
- Chongqing University of Science and Technology, Chong Qing, 401331, PR China
| | - Pei Wu
- Chongqing University of Science and Technology, Chong Qing, 401331, PR China
| | - Da Sun
- Institute of Life Sciences & Biomedicine Collaborative Innovation Center, Wenzhou University, Wenzhou, 325000, PR China
| |
Collapse
|
22
|
Zhang L, Lyu K, Wang N, Gu L, Sun Y, Zhu X, Wang J, Huang Y, Yang Z. Transcriptomic Analysis Reveals the Pathways Associated with Resisting and Degrading Microcystin in Ochromonas. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11102-11113. [PMID: 30176726 DOI: 10.1021/acs.est.8b03106] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Toxic Microcystis bloom is a tough environment problem worldwide. Microcystin is highly toxic and is an easily accumulated secondary metabolite of toxic Microcystis that threatens water safety. Biodegradation of microcystin by protozoan grazing is a promising and efficient biological method, but the mechanism in this process is still unclear. The present study aimed to identify potential pathways involved in resisting and degrading microcystin in flagellates through transcriptomic analyses. A total of 999 unigenes were significantly differentially expressed between treatments with flagellates Ochromonas fed on microcystin-producing Microcystis and microcystin-free Microcystis. These dysregulated genes were strongly associated with translation, carbohydrate metabolism, phagosome, and energy metabolism. Upregulated genes encoding peroxiredoxin, serine/threonine-protein phosphatase, glutathione S-transferase (GST), HSP70, and O-GlcNAc transferase were involved in resisting microcystin. In addition, genes encoding cathepsin and GST and genes related to inducing reactive oxygen species (ROS) were all upregulated, which highly probably linked with degrading microcystin in flagellates. The results of this study provided a better understanding of transcriptomic responses of flagellates to toxic Microcystis as well as highlighted a potential mechanism of biodegrading microcystin by flagellate Ochromonas, which served as a strong theoretical support for control of toxic microalgae by protozoans.
Collapse
Affiliation(s)
- Lu Zhang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Kai Lyu
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Na Wang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Lei Gu
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Yunfei Sun
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Xuexia Zhu
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Jun Wang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Yuan Huang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
| | - Zhou Yang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences , Nanjing Normal University , 1 Wenyuan Road , Nanjing 210023 , China
- Department of Ecology, College of Life Science and Technology , Jinan University , Guangzhou 510632 , China
| |
Collapse
|
23
|
Islam A, Jeon D, Ra J, Shin J, Kim TY, Lee Y. Transformation of microcystin-LR and olefinic compounds by ferrate(VI): Oxidative cleavage of olefinic double bonds as the primary reaction pathway. WATER RESEARCH 2018; 141:268-278. [PMID: 29800835 DOI: 10.1016/j.watres.2018.05.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/01/2018] [Accepted: 05/06/2018] [Indexed: 06/08/2023]
Abstract
The presence of toxic microcystins in algal-impacted surface waters is a concern for drinking water quality management. In this study, the potential of ferrate(VI) to eliminate microcystins during drinking water treatment was assessed by investigating reaction kinetics, reaction sites, transformation products, and toxicity changes for the oxidation of microcystin-LR (MC-LR) as a representative microsystin. The investigations also included several substructural model compounds of MC-LR, such as cinnamic acid and sorbic acid, to elucidate the major transformation products and pathways of MC-LR and olefinic compounds. Second-order rate constants were determined in the pH range 6-10.4 for the reaction of ferrate(VI) with MC-LR and the model compounds. The kinetic data revealed that the olefinic double bonds in the Adda and Mdha residues of MC-LR were the primary ferrate(VI) reaction sites, while the phenyl or guanidine moiety was not the reaction site. This finding was supported by detection and identification of the MC-LR transformation products of double bond cleavage, with high peak abundance in the liquid chromatography-mass spectrometry. Furthermore, the reaction of ferrate(VI) with cinnamic and sorbic acids formed the corresponding aldehydes and organic acids with near complete carbon mass balance, indicating the oxidative cleavage of the double bonds as the primary reaction pathway. A quantitative protein phosphatase 2A (PP2A) binding assay for ferrate(VI)-treated MC-LR solutions showed that the MC-LR transformation products exhibited negligible PP2A binding activity compared to that of the parent MC-LR. Oxidation experiments in a filtered river water matrix spiked with MC-LR demonstrated the efficient elimination of MC-LR during water treatment with ferrate(VI).
Collapse
Affiliation(s)
- Ananna Islam
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Dahee Jeon
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Jiwoon Ra
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Jaedon Shin
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Tae-Young Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Yunho Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
| |
Collapse
|
24
|
Zong W, Wang Q, Zhang S, Teng Y, Du Y. Regulation on the toxicity of microcystin-LR target to protein phosphatase 1 by biotransformation pathway: effectiveness and mechanism. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:26020-26029. [PMID: 29968216 DOI: 10.1007/s11356-018-2676-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 06/26/2018] [Indexed: 06/08/2023]
Abstract
Biotransformation was an important pathway to regulate the toxicity of microcystins (MCs) targeted to protein phosphatases (PPs). To explore the regulation effectiveness and mechanism, several typical biothiol transformation products originated from MCLR were prepared by nucleophilic addition reaction. The reduced inhibition effect of MCLR transformation products on PP1 was evaluated and compared with their original toxin. Though molecular simulation showed the introduced biothiols enhanced the total combination areas and energies for target complexes, the steric hindrance of introduced biothiols inhibited the combination between the key action sites (Mdha7 and Adda5 residues) and PP1. Furthermore, the introduced biothiols also weakened the hydrogen bonds for some key interaction sites and altered the ion bonds between PP1 and the two Mn2+ ions in the catalytic center. The discrepant regulation effect for biothiols on the toxicity of MCLR was closely related to above indexes and influenced by molecular sides.
Collapse
Affiliation(s)
- Wansong Zong
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China.
| | - Qian Wang
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China
| | - Shuhan Zhang
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China
| | - Yue Teng
- School of Environmental and Civil Engineering, Jiangnan University, 1800# Lihu Avenue, Wuxi, 214122, Jiangsu, China
| | - Yonggang Du
- College of Geography and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan, 250014, Shandong, China
| |
Collapse
|
25
|
Duan X, Sanan T, de la Cruz A, He X, Kong M, Dionysiou DD. Susceptibility of the Algal Toxin Microcystin-LR to UV/Chlorine Process: Comparison with Chlorination. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8252-8262. [PMID: 29920077 PMCID: PMC7382943 DOI: 10.1021/acs.est.8b00034] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Microcystin-LR (MC-LR), an algal toxin (cyanotoxin) common in sources of drinking water, poses a major human health hazard due to its high toxicity. In this study, UV/chlorine was evaluated as a potentially practical and effective process for the degradation of MC-LR. Via mass spectrometry analysis, fewer chlorinated-MC-LR products were detected with UV/chlorine treatment than with chlorination, and a transformation pathway for MC-LR by UV/chlorine was proposed. Different degrees of rapid degradation of MC-LR were observed with varying pH (6-10.4), oxidant dosage (0.5-3 mg L-1), natural organic matter (0-7 mg L-1), and natural water sources. In contrast to the formation of primarily chloroform and dichloroacetic acid in deionized water where MC-LR serves as the only carbon source, additional chlorinated disinfection byproducts were produced when sand filtered natural water was used as a background matrix. The UV/chlorine treated samples also showed quantitatively less cytotoxicity in vitro in HepaRG human liver cell line tests than chlorination treated samples. Following 16 min (96 mJ cm-2) of UV irradiation combined with 1.5 mg L-1 chlorine treatment, the cell viability of the samples increased from 80% after exposure to 1 mg L-1 MC-LR to 90%, while chlorination treatment evidenced no reduction in cytotoxicity with the same reaction time.
Collapse
Affiliation(s)
- Xiaodi Duan
- Environmental Engineering and Science, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Toby Sanan
- Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, United States
| | - Armah de la Cruz
- Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, United States
| | - Xuexiang He
- Environmental Engineering and Science, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Minghao Kong
- Environmental Engineering and Science, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, Ohio 45221, United States
| | | |
Collapse
|
26
|
Evaluation of the Direct and Indirect Regulation Pathways of Glutathione Target to the Hepatotoxicity of Microcystin-LR. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5672637. [PMID: 30050937 PMCID: PMC6040258 DOI: 10.1155/2018/5672637] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/22/2018] [Accepted: 06/03/2018] [Indexed: 11/24/2022]
Abstract
Glutathione (GSH) plays crucial roles in regulating the hepatotoxicity of Microcystin-LR (MCLR) by inhibiting oxidative stress or by toxin conjugation. Based on MCLR conjugation product preparation and purification, the direct and indirect regulation pathways for GSH were fully evaluated. Protein phosphatase inhibition analysis verified that GSH conjugation was an effective pathway to regulate the inhibition effect of MCLR, while GSH had slight influence on the toxicity of MCLR. Research on oxidative stress showed that both regulation pathways could reduce the formation of reactive oxygen species (stimulated by MCLR and regulated by NADH oxidase) and regulate the adverse effects on antioxidant enzymes. By evaluating the contributions for both pathways, it could be found that the indirect pathway had significant contribution to eliminating cellular reactive oxygen species and regulating protein phosphatases inhibition, while the direct regulation pathway had moderate influence. As glutathione transferases facilitated the transformation of MCLR, the hepatotoxicity of MCLR could be effectively regulated by GSH conjugation pathway, especially with abundant exogenous GSH.
Collapse
|
27
|
Dubrawski KL, Cataldo M, Dubrawski Z, Mazumder A, Wilkinson DP, Mohseni M. In-situ electrochemical Fe(VI) for removal of microcystin-LR from drinking water: comparing dosing of the ferrate ion by electrochemical and chemical means. JOURNAL OF WATER AND HEALTH 2018; 16:414-424. [PMID: 29952330 DOI: 10.2166/wh.2018.187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Harmful algal blooms (HAB) release microtoxins that contaminate drinking water supplies and risk the health of millions annually. Crystalline ferrate(VI) is a powerful oxidant capable of removing algal microtoxins. We investigate in-situ electrochemically produced ferrate from common carbon steel as an on-demand alternative to crystalline ferrate for the removal of microcystin-LR (MC-LR) and compare the removal efficacy for both electrochemical (EC) and chemical dosing methodologies. We report that a very low dose of EC-ferrate in deionized water (0.5 mg FeO42- L-1) oxidizes MC-LR (MC-LR0 = 10 μg L-1) to below the guideline limit (1.0 μg L-1) within 10 minutes' contact time. With bicarbonate or natural organic matter (NOM), doses of 2.0-5.0 mg FeO42- L-1 are required, with lower efficacy of EC-ferrate than crystalline ferrate due to loss of EC-ferrate by water oxidation. To evaluate the EC-ferrate process to concurrently oxidize micropollutants, coagulate NOM, and disinfect drinking water, we spiked NOM-containing real water with MC-LR and Escherichia coli, finding that EC-ferrate is effective at 10.0 mg FeO42- L-1 under normal operation or 2.0 mg FeO42- L-1 if the test water has initial pH optimized. We suggest in-situ EC-ferrate may be appropriate for sporadic HAB events in small water systems as a primary or back-up technology.
Collapse
Affiliation(s)
- K L Dubrawski
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada E-mail:
| | - M Cataldo
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada E-mail:
| | - Z Dubrawski
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada E-mail:
| | - A Mazumder
- Water and Aquatic Sciences Research Program, Department of Biology, University of Victoria, Victoria, BC, Canada
| | - D P Wilkinson
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada E-mail:
| | - M Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada E-mail:
| |
Collapse
|
28
|
Rosenblum L, Zaffiro A, Adams WA, Wendelken SC. Effect of chlorination by-products on the quantitation of microcystins in finished drinking water. Toxicon 2017; 138:138-144. [PMID: 28860036 DOI: 10.1016/j.toxicon.2017.08.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/24/2017] [Accepted: 08/26/2017] [Indexed: 11/18/2022]
Abstract
Microcystins are toxic peptides that can be produced by cyanobacteria in harmful algal blooms (HABs). Various analytical techniques have been developed to quantify microcystins in drinking water, including liquid chromatography tandem mass spectrometry (LC/MS/MS), enzyme linked immunosorbent assay (ELISA), and oxidative cleavage to produce 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB) with detection by LC/MS/MS, the "MMPB method". Both the ELISA and MMPB methods quantify microcystins by detecting a portion of the molecule common to most microcystins. However, there is little research evaluating the effect of microcystin chlorination by-products potentially produced during drinking water treatment on analytical results. To evaluate this potential, chlorinated drinking water samples were fortified with various microcystin congeners in bench-scale studies. The samples were allowed to react, followed by a comparison of microcystin concentrations measured using the three methods. The congener-specific LC/MS/MS method selectively quantified microcystins and was not affected by the presence of chlorination by-products. The ELISA results were similar to those obtained by LC/MS/MS for most microcystin congeners, but results deviated for a particular microcystin containing a variable amino acid susceptible to oxidation. The concentrations measured by the MMPB method were at least five-fold higher than the concentrations of microcystin measured by the other methods and demonstrate that detection of MMPB does not necessarily correlate to intact microcystin toxins in finished drinking water.
Collapse
Affiliation(s)
- Laura Rosenblum
- CB&I Federal Services, 26 W. Martin Luther King, Cincinnati, OH 45268, USA
| | - Alan Zaffiro
- CB&I Federal Services, 26 W. Martin Luther King, Cincinnati, OH 45268, USA
| | - William A Adams
- US EPA Office of Water, 26 W. Martin Luther King, Cincinnati, OH 45268, USA.
| | - Steven C Wendelken
- US EPA Office of Water, 26 W. Martin Luther King, Cincinnati, OH 45268, USA
| |
Collapse
|
29
|
Kim MS, Kim HH, Lee KM, Lee HJ, Lee C. Oxidation of microcystin-LR by ferrous-tetrapolyphosphate in the presence of oxygen and hydrogen peroxide. WATER RESEARCH 2017; 114:277-285. [PMID: 28254645 DOI: 10.1016/j.watres.2017.02.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/17/2017] [Accepted: 02/17/2017] [Indexed: 06/06/2023]
Abstract
Ferrous-tetrapolyphosphate complexes (Fe(II)-TPP) activate oxygen and hydrogen peroxide to produce reactive oxidants capable of degrading organic compounds. In this study, the Fe(II)-TPP/O2 and Fe(II)-TPP/H2O2 systems were assessed for oxidative degradation of microcystin-LR (MC-LR), the most toxic and abundant cyanotoxin. The degradation of MC-LR was optimized for both the Fe(II)-TPP/O2 and Fe(II)-TPP/H2O2 systems when the molar ratio of TPP:Fe(II) was approximately 5.7-5.9. The optimal H2O2 dose for MC-LR degradation by Fe(II)-TPP/H2O2 was found to be 320 μM. The Fe(II)-TPP/O2 and Fe(II)-TPP/H2O2 systems exhibited two pH optima for MC-LR degradation i.e., ∼7 and 9, which can be attributed to pH-dependent reactivity changes of the resultant oxidants (most likely the ferryl-tetrapolyphostate complex, Fe(IV)-TPP). Liquid chromatography-mass spectrometry identified 22 compounds produced by the oxidation of MC-LR, including four primary oxidation products. One of the primary products, in particular, was formed via oxidative cleavage of the alkene group in the Mdha moiety of MC-LR. This compound and its secondary oxidation products are rarely found when MC-LR is transformed by other oxidants and is believed to reflect a unique reaction pathway involving Fe(IV)-TPP. Meanwhile, the hepatotoxicity of the reaction solution decreased concurrently with a decrease on MC-LR concentration.
Collapse
Affiliation(s)
- Min Sik Kim
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan, 44919, Republic of Korea
| | - Hak-Hyeon Kim
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan, 44919, Republic of Korea
| | - Ki-Myeong Lee
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan, 44919, Republic of Korea
| | - Hye-Jin Lee
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan, 44919, Republic of Korea
| | - Changha Lee
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan, 44919, Republic of Korea.
| |
Collapse
|
30
|
Jeong B, Oh MS, Park HM, Park C, Kim EJ, Hong SW. Elimination of microcystin-LR and residual Mn species using permanganate and powdered activated carbon: Oxidation products and pathways. WATER RESEARCH 2017; 114:189-199. [PMID: 28249210 DOI: 10.1016/j.watres.2017.02.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/15/2017] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
The oxidation of microcystin-LR (MC-LR) in deionized water (DI) and river water using potassium permanganate (KMnO4) at a neutral pH and at 23 ± 2 °C was investigated. These two aqueous systems (i.e., DI and river water) gave comparable second-order rate constants (289.9 and 285.5 M-1s-1 (r2 > 0.99), respectively), which confirmed the effectiveness of this oxidation process for the treatment of natural surface water. The presence of either humic or fulvic acid reduced the removal efficiency of MC-LR, with the latter exhibiting a greater inhibitory effect. Monitoring of MC-LR and residual Mn2+ levels with adding KMnO4 (1 mg/L) and powdered activated carbon (PAC, 5-20 mg L-1) before and during coagulation, respectively, revealed that 60 min of permanganate pre-oxidation followed by coagulant addition with PAC was the most effective approach for reducing both levels below limits stated by WHO guidelines. The MC-LR degradation products were the result of oxidation occurring at the diene and aromatic moieties of the Adda (3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid) side-chain, in addition to amine bond hydrolysis of the Mdha (N-methyldehydroalanine) moiety. Several toxic by-products with an intact Adda chain were observed during the reaction, but completely disappeared after 60 min. This further supports the conclusion that sufficient contact time with permanganate (i.e., >60 min) is essential to reducing the residual toxicity and maximizing the efficiency of MC-LR oxidation when treating raw water.
Collapse
Affiliation(s)
- Boyoung Jeong
- Center for Water Resources Cycle Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Min-Seok Oh
- Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Hyun-Mee Park
- Advanced Analysis Center, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Chanhyuk Park
- Center for Water Resources Cycle Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Eun-Ju Kim
- Center for Water Resources Cycle Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea; Energy and Environmental Engineering, Korea University of Science and Technology, Seoul, 02792, Republic of Korea.
| | - Seok Won Hong
- Center for Water Resources Cycle Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea; Energy and Environmental Engineering, Korea University of Science and Technology, Seoul, 02792, Republic of Korea.
| |
Collapse
|
31
|
Meglič A, Pecman A, Rozina T, Leštan D, Sedmak B. Electrochemical inactivation of cyanobacteria and microcystin degradation using a boron-doped diamond anode - A potential tool for cyanobacterial bloom control. J Environ Sci (China) 2017; 53:248-261. [PMID: 28372749 DOI: 10.1016/j.jes.2016.02.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 10/21/2015] [Accepted: 02/19/2016] [Indexed: 06/07/2023]
Abstract
Cyanobacterial blooms are global phenomena that can occur in calm and nutrient-rich (eutrophic) fresh and marine waters. Human exposure to cyanobacteria and their biologically active products is possible during water sports and various water activities, or by ingestion of contaminated water. Although the vast majority of harmful cyanobacterial products are confined to the interior of the cells, these are eventually released into the surrounding water following natural or artificially induced cell death. Electrochemical oxidation has been used here to damage cyanobacteria to halt their proliferation, and for microcystin degradation under in-vitro conditions. Partially spent Jaworski growth medium with no addition of supporting electrolytes was used. Electrochemical treatment resulted in the cyanobacterial loss of cell-buoyancy regulation, cell proliferation arrest, and eventual cell death. Microcystin degradation was studied separately in two basic modes of treatment: batch-wise flow, and constant flow, for electrolytic-cell exposure. Batch-wise exposure simulates treatment under environmental conditions, while constant flow is more appropriate for the study of boron-doped diamond electrode efficacy under laboratory conditions. The effectiveness of microcystin degradation was established using high-performance liquid chromatography-photodiode array detector analysis, while the biological activities of the products were estimated using a colorimetric protein phosphatase-1 inhibition assay. The results indicate potential for the application of electro-oxidation methods for the control of bloom events by taking advantage of specific intrinsic ecological characteristics of bloom-forming cyanobacteria. The applicability of the use of boron-doped diamond electrodes in remediation of water exposed to cyanobacteria bloom events is discussed.
Collapse
Affiliation(s)
- Andrej Meglič
- Arhel Ltd., Pustovrhova c. 63, SI-1000 Ljubljana, Slovenia.
| | - Anja Pecman
- Centre for Soil and Environmental Sciences, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | | | - Domen Leštan
- Centre for Soil and Environmental Sciences, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - Bojan Sedmak
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, SI-1000 Ljubljana, Slovenia.
| |
Collapse
|
32
|
Molecular Mechanism for the Regulation of Microcystin Toxicity to Protein Phosphatase 1 by Glutathione Conjugation Pathway. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9676504. [PMID: 28337461 PMCID: PMC5350311 DOI: 10.1155/2017/9676504] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 11/08/2016] [Accepted: 11/15/2016] [Indexed: 11/21/2022]
Abstract
Glutathione (GSH) conjugation was an important pathway to regulate the toxicity of microcystins (MCs) targeted to protein phosphatases. To explore the specific molecular mechanism for GSH detoxification, two typical MC-GSHs (derived from MCLR and MCRR) were synthesized, prepared, and purified according to previous research. Then, the reduced inhibition effect for MC-GSHs on protein phosphatase 1 was verified by comparing with their original toxins. To further clarify the molecular mechanism for MC-GSHs detoxification, we evaluated the interactions between MCs/MC-GSHs and PP1 with the assistance of MOE molecule simulation. When GSH was introduced to MCs, the covalent binding (Mdha7 to Cys273), the hydrophobic interaction (Adda5 with PP1), the hydrogen bonds (especially for Lys2-Arg96 and Glu6-Tyr272), the covalent combination (between Mdha7 and Cys273), and the ion bonds (between Mn2+ and Asn124/His248/Asp64/His66) of MCLR/MCRR-PP1 complexes weakened to a certain extent, while the ion bonds between Mn2+ and His173/Asp92 residues increased. It was not difficult to find that the toxicity of MCs was closely related to the above sites/interactions and the above key information for MCs-PP1; MC-GSHs-PP1 complexes were important for clarifying the detoxification mechanism of MC-GSHs pathway. This study offers a comprehensive cognition on MCs toxicity regulation and provides valid theoretical support to control their potential risk.
Collapse
|
33
|
Liu J, Ye JS, Ou HS, Lin J. Effectiveness and intermediates of microcystin-LR degradation by UV/H 2O 2 via 265 nm ultraviolet light-emitting diodes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:4676-4684. [PMID: 27975200 DOI: 10.1007/s11356-016-8148-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 11/23/2016] [Indexed: 06/06/2023]
Abstract
Although the degradation of cyanotoxins by 254 nm UV/H2O2 has been well elucidated, the efficiency and mechanism involved are not necessarily true for other UV wavelengths. The degradation of microcystin-LR (MC-LR), a representative cyanotoxin, was explored by UV/H2O2 using 265 nm ultraviolet light-emitting diode (UV-LED). The results indicated that 265 nm UV/H2O2 treatment had a high removal efficiency of MC-LR ([MC-LR] = 0.1 μM, apparent rate constants reached 0.2077 min-1, half-time at 3.3 min). The qualitative analyses demonstrated that three novel intermediates, C48H74N10O15 (molecular weight = 1030.5335), C36H58N10O14 (854.4134), and C33H54N10O14 (814.3821), were generated in 265 nm UV/H2O2. Five published intermediates were also confirmed. The generative pathway of these products mainly involved free hydroxyl radical oxidation, resulting in consecutive hydroxyl substitutions and hydroxyl additions of unsaturated bonds in MC-LR. The toxicity of MC-LR was weaken with a relative low mineralization. The electrical energy per order values were calculated to be in the range of 0.00447 to 0.00612 kWh m-3 order-1 for 100-5000 μg L-1 MC-LR. Overall, 265 nm UV-LED/H2O2 can be used as an alternative effective technology to improve the removal efficiency of MC-LR in water.
Collapse
Affiliation(s)
- Juan Liu
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Jin-Shao Ye
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
- Lawrence Berkeley National Laboratory, Joint Genome Institute, Walnut Creek, CA, 94598, USA
| | - Hua-Se Ou
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China.
| | - Jialing Lin
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| |
Collapse
|
34
|
Zhang Y, Wei H, Xin Q, Wang M, Wang Q, Wang Q, Cong Y. Process optimization for microcystin-LR degradation by Response Surface Methodology and mechanism analysis in gas-liquid hybrid discharge system. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 183:726-732. [PMID: 27641651 DOI: 10.1016/j.jenvman.2016.09.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 09/07/2016] [Accepted: 09/08/2016] [Indexed: 06/06/2023]
Abstract
A gas-liquid hybrid discharge system was applied to microcystin-LR (MC-LR) degradation. MC-LR degradation was completed after 1 min under a pulsed high voltage of 16 kV, gas-liquid interface gap of 10 mm and oxygen flow rate of 160 L/h. The Box-Behnken Design was proposed in Response Surface Methodology to evaluate the influence of pulsed high voltage, electrode distance and oxygen flow rate on MC-LR removal efficiency. Multiple regression analysis, focused on multivariable factors, was employed and a reduced cubic model was developed. The ANOVA analysis shows that the model is significant and the model prediction on MC-LR removal was also validated with experimental data. The optimum conditions for the process are obtained at pulsed voltage of 16 kV, gas-liquid interface gap of 10 mm and oxygen flow rate of 120 L/h with ta removal efficiency of MC-LR of 96.6%. The addition of catalysts (TiO2 or Fe2+) in the gas-liquid hybrid discharge system was found to enhance the removal of MC-LR. The intermediates of MC-LR degradation were analyzed by liquid chromatography/mass spectrometry. The degradation pathway proposed envisaged the oxidation of hydroxyl radicals and ozone, and attack of high-energy electrons on the unsaturated double bonds of Adda and Mdha, with MC-LR finally decomposing into small molecular products.
Collapse
Affiliation(s)
- Yi Zhang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, Zhejiang, PR China
| | - Hanyu Wei
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, Zhejiang, PR China
| | - Qing Xin
- College of Electronic Information, Hangzhou Dianzi University, Hangzhou, 310018, PR China
| | - Mingang Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, Zhejiang, PR China
| | - Qi Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, Zhejiang, PR China
| | - Qiang Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, Zhejiang, PR China
| | - Yanqing Cong
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, Zhejiang, PR China.
| |
Collapse
|
35
|
Zhang X, Li J, Yang JY, Wood KV, Rothwell AP, Li W, Blatchley Iii ER. Chlorine/UV Process for Decomposition and Detoxification of Microcystin-LR. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7671-7678. [PMID: 27338715 DOI: 10.1021/acs.est.6b02009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Microcystin-LR (MC-LR) is a potent hepatotoxin that is often associated with blooms of cyanobacteria. Experiments were conducted to evaluate the efficiency of the chlorine/UV process for MC-LR decomposition and detoxification. Chlorinated MC-LR was observed to be more photoactive than MC-LR. LC/MS analyses confirmed that the arginine moiety represented an important reaction site within the MC-LR molecule for conditions of chlorination below the chlorine demand of the molecule. Prechlorination activated MC-LR toward UV254 exposure by increasing the product of the molar absorption coefficient and the quantum yield of chloro-MC-LR, relative to the unchlorinated molecule. This mechanism of decay is fundamentally different than the conventional view of chlorine/UV as an advanced oxidation process. A toxicity assay based on human liver cells indicated MC-LR degradation byproducts in the chlorine/UV process possessed less cytotoxicity than those that resulted from chlorination or UV254 irradiation applied separately. MC-LR decomposition and detoxification in this combined process were more effective at pH 8.5 than at pH 7.5 or 6.5. These results suggest that the chlorine/UV process could represent an effective strategy for control of microcystins and their associated toxicity in drinking water supplies.
Collapse
Affiliation(s)
- Xinran Zhang
- School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, China
| | - Jing Li
- Department of Applied Chemistry, China Agricultural University , Beijing, China
| | - Jer-Yen Yang
- Department of Basic Medical Sciences & Center for Cancer Research, Purdue University , West Lafayette, Indiana 47907, United States
| | - Karl V Wood
- Campus-Wide Mass Spectrometry Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Arlene P Rothwell
- Campus-Wide Mass Spectrometry Center, Purdue University , West Lafayette, Indiana 47907, United States
| | - Weiguang Li
- School of Municipal and Environmental Engineering, Harbin Institute of Technology , Harbin, China
| | - Ernest R Blatchley Iii
- Lyles School of Civil Engineering, Purdue University , West Lafayette, Indiana 47907, United States
- Division of Environmental & Ecological Engineering, Purdue University , West Lafayette, Indiana 47907, United States
| |
Collapse
|
36
|
Zhou S, Yin H, Tang S, Peng H, Yin D, Yang Y, Liu Z, Dang Z. Physiological responses of Microcystis aeruginosa against the algicidal bacterium Pseudomonas aeruginosa. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2016; 127:214-221. [PMID: 26866757 DOI: 10.1016/j.ecoenv.2016.02.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/02/2016] [Accepted: 02/02/2016] [Indexed: 06/05/2023]
Abstract
Proliferation of cyanobacteria in aquatic ecosystems has caused water security problems throughout the world. Our preliminary study has showed that Pseudomonas aeruginosa can inhibit the growth of cyanobacterium, Microcystis aeruginosa. In order to explore the inhibitory mechanism of P. aeruginosa on the cell growth and synthesis of intracellular substances of M. aeruginosa, concentrations of Chlorophyll-a, intracellular protein, carbohydrate, enzyme activities and ion metabolism of M. aeruginosa, were investigated. The results indicated that 83.84% algicidal efficiency of P. aeruginosa was achieved after treatment for 7 days. The strain inhibited the reproduction of M. aeruginosa by impeding the synthesis of intracellular protein and carbohydrate of cyanobacterium, and only a very small part of intracellular protein and carbohydrate was detected after exposure to P. aeruginosa for 5 days. P. aeruginosa caused the alteration of intracellular antioxidant enzyme activity of M. aeruginosa, such as catalase, peroxidase. The accumulation of malondialdehyde aggravated membrane injury after treatment for 3 days. P. aeruginosa also affected the ion metabolism of cyanobacteria. The release of Na(+) and Cl(-) was significantly enhanced while the uptake of K(+), Ca(2+), Mg(2+), NO3(-) and SO4(2)(-) decreased. Surface morphology and intracellular structure of cyanobacteria and bacterial cells changed dramatically over time as evidenced by electron microscope (SEM) and transmission electron microscope (TEM) analysis. These results revealed that the algicidal activity of P. aeruginosa was primarily due to the fermentation liquid of P. aeruginosa that impeded the synthesis of intracellular protein and carbohydrate, and damaged the cell membrane through membrane lipid peroxidation.
Collapse
Affiliation(s)
- Su Zhou
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006,Guangdong, China
| | - Hua Yin
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006,Guangdong, China.
| | - Shaoyu Tang
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006,Guangdong, China
| | - Hui Peng
- Department of Chemistry, Jinan University, Guangzhou 510632, Guangdong, China
| | - Donggao Yin
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006,Guangdong, China
| | - Yixuan Yang
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006,Guangdong, China
| | - Zehua Liu
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006,Guangdong, China
| | - Zhi Dang
- Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006,Guangdong, China
| |
Collapse
|
37
|
Zhang R, Yang Y, Huang CH, Li N, Liu H, Zhao L, Sun P. UV/H2O2 and UV/PDS Treatment of Trimethoprim and Sulfamethoxazole in Synthetic Human Urine: Transformation Products and Toxicity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2573-2583. [PMID: 26840504 DOI: 10.1021/acs.est.5b05604] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Elimination of pharmaceuticals in source-separated human urine is a promising approach to minimize the pharmaceuticals in the environment. Although the degradation kinetics of pharmaceuticals by UV/H2O2 and UV/peroxydisulfate (PDS) processes has been investigated in synthetic fresh and hydrolyzed urine, comprehensive evaluation of the advanced oxidation processes (AOPs), such as product identification and toxicity testing, has not yet been performed. This study identified the transformation products of two commonly used antibiotics, trimethoprim (TMP) and sulfamethoxazole (SMX), by UV/H2O2 and UV/PDS in synthetic urine matrices. The effects of reactive species, including •OH, SO4(•-), CO3(•-), and reactive nitrogen species, on product generation were investigated. Multiple isomeric transformation products of TMP and SMX were observed, especially in the reaction with hydroxyl radical. SO4(•-) and CO3(•-) reacted with pharmaceuticals by electron transfer, thus producing similar major products. The main reactive species deduced on the basis of product generation are in good agreement with kinetic simulation of the advanced oxidation processes. A strain identified as a polyphosphate-accumulating organism was used to investigate the antimicrobial activity of the pharmaceuticals and their products. No antimicrobial property was detected for the transformation products of either TMP or SMX. Acute toxicity employing luminescent bacterium Vibrio qinghaiensis indicated 20-40% higher inhibitory effect of TMP and SMX after treatment. Ecotoxicity was estimated by quantitative structure-activity relationship analysis using ECOSAR.
Collapse
Affiliation(s)
- Ruochun Zhang
- School of Environmental Science and Engineering, Tianjin University , Tianjin 300072, China
| | - Yongkui Yang
- School of Environmental Science and Engineering, Tianjin University , Tianjin 300072, China
| | - Ching-Hua Huang
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Na Li
- Tianjin Institute of Agriculture Quality Standards and Testing Technology , Tianjin 300381, China
| | - Hang Liu
- School of Environmental Science and Engineering, Tianjin University , Tianjin 300072, China
| | - Lin Zhao
- School of Environmental Science and Engineering, Tianjin University , Tianjin 300072, China
| | - Peizhe Sun
- School of Civil and Environmental Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| |
Collapse
|
38
|
He X, de la Cruz AA, Hiskia A, Kaloudis T, O'Shea K, Dionysiou DD. Destruction of microcystins (cyanotoxins) by UV-254 nm-based direct photolysis and advanced oxidation processes (AOPs): influence of variable amino acids on the degradation kinetics and reaction mechanisms. WATER RESEARCH 2015; 74:227-238. [PMID: 25744186 DOI: 10.1016/j.watres.2015.02.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 02/04/2015] [Accepted: 02/06/2015] [Indexed: 06/04/2023]
Abstract
Hepatotoxic microcystins (MCs) are the most frequently detected group of cyanobacterial toxins. This study investigated the degradation of common MC variants in water, MC-LR, MC-RR, MC-YR and MC-LA, by UV-254 nm-based processes, UV only, UV/H2O2, UV/S2O8(2-) and UV/HSO5(-). Limited direct photolysis of MCs was observed, while the addition of an oxidant significantly improved the degradation efficiency with an order of UV/S2O8(2-) > UV/HSO5(-) > UV/H2O2 at the same initial molar concentration of the oxidant. The removal of MC-LR by UV/H2O2 appeared to be faster than another cyanotoxin, cylindrospermopsin, at either the same initial molar concentration or the same initial organic carbon concentration of the toxin. It suggested a faster reaction of MC-LR with hydroxyl radical, which was further supported by the determined second-order rate constant of MCs with hydroxyl radical. Both isomerization and photohydration byproducts were observed in UV only process for all four MCs; while in UV/H2O2, hydroxylation and diene-Adda double bond cleavage byproducts were detected. The presence of a tyrosine in the structure of MC-YR significantly promoted the formation of monohydroxylation byproduct m/z 1061; while the presence of a second arginine in MC-RR led to the elimination of a guanidine group and the absence of double bond cleavage byproducts. It was therefore demonstrated in this study that the variable amino acids in the structure of MCs influenced not only the degradation kinetics but also the preferable reaction mechanisms.
Collapse
Affiliation(s)
- Xuexiang He
- Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012, United States; Nireas-International Water Research Centre, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
| | - Armah A de la Cruz
- Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH 45268, United States
| | - Anastasia Hiskia
- Institute of Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems, National Center for Scientific Research "Demokritos", Patriarchou Grigoriou & Neapoleos, 15310 Agia Paraskevi, Athens, Greece
| | - Triantafyllos Kaloudis
- Water Quality Department, Athens Water Supply and Sewerage Company (EYDAP SA), Oropou 156, 11146 Galatsi, Athens, Greece
| | - Kevin O'Shea
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012, United States; Nireas-International Water Research Centre, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus.
| |
Collapse
|
39
|
Jiang W, Chen L, Batchu SR, Gardinali PR, Jasa L, Marsalek B, Zboril R, Dionysiou DD, O'Shea KE, Sharma VK. Oxidation of microcystin-LR by ferrate(VI): kinetics, degradation pathways, and toxicity assessments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:12164-12172. [PMID: 25215438 DOI: 10.1021/es5030355] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The presence of the potent cyanotoxin, microcystin-LR (MC-LR), in drinking water sources poses a serious risk to public health. The kinetics of the reactivity of ferrate(VI) (Fe(VI)O4(2-), Fe(VI)) with MC-LR and model compounds (sorbic acid, sorbic alcohol, and glycine anhydride) are reported over a range of solution pH. The degradation of MC-LR followed second-order kinetics with the bimolecular rate constant (kMCLR+Fe(VI)) decreasing from 1.3 ± 0.1 × 10(2) M(-1) s(-1) at pH 7.5 to 8.1 ± 0.08 M(-1) s(-1) at pH 10.0. The specific rate constants for the individual ferrate species were determined and compared with a number of common chemical oxidants employed for water treatment. Detailed product studies using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) indicated the oxidized products (OPs) were primarily the result of hydroxylation of the aromatic ring, double bond of the methyldehydroalanine (Mdha) amino acid residue, and diene functionality. Products studies also indicate fragmentation of the cyclic MC-LR structure occurs under the reaction conditions. The analysis of protein phosphatase (PP1) activity suggested that the degradation byproducts of MC-LR did not possess significant biological toxicity. Fe(VI) was effective for the degradation MC-LR in water containing carbonate ions and fulvic acid (FA) and in lake water samples, but higher Fe(VI) dosages would be needed to completely remove MC-LR in lake water compared to deionized water.
Collapse
Affiliation(s)
- Wenjun Jiang
- Department of Chemistry and Biochemistry, Florida International University , 11200 SW Eighth Street, Miami, Florida 33199, United States
| | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
He X, Mezyk SP, Michael I, Fatta-Kassinos D, Dionysiou DD. Degradation kinetics and mechanism of β-lactam antibiotics by the activation of H2O2 and Na2S2O8 under UV-254nm irradiation. JOURNAL OF HAZARDOUS MATERIALS 2014; 279:375-383. [PMID: 25086235 DOI: 10.1016/j.jhazmat.2014.07.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/07/2014] [Accepted: 07/09/2014] [Indexed: 06/03/2023]
Abstract
The extensive production and usage of antibiotics have led to an increasing occurrence of antibiotic residuals in various aquatic compartments, presenting a significant threat to both ecosystem and human health. This study investigated the degradation of selected β-lactam antibiotics (penicillins: ampicillin, penicillin V, and piperacillin; cephalosporin: cephalothin) by UV-254nm activated H2O2 and S2O8(2-) photochemical processes. The UV irradiation alone resulted in various degrees of direct photolysis of the antibiotics; while the addition of the oxidants improved significantly the removal efficiency. The steady-state radical concentrations were estimated, revealing a non-negligible contribution of hydroxyl radicals in the UV/S2O8(2-) system. Mineralization of the β-lactams could be achieved at high UV fluence, with a slow formation of SO4(2-) and a much lower elimination of total organic carbon (TOC). The transformation mechanisms were also investigated showing the main reaction pathways of hydroxylation (+16Da) at the aromatic ring and/or the sulfur atom, hydrolysis (+18Da) at the β-lactam ring and decarboxylation (-44Da) for the three penicillins. Oxidation of amine group was also observed for ampicillin. This study suggests that UV/H2O2 and UV/S2O8(2-) advanced oxidation processes (AOPs) are capable of degrading β-lactam antibiotics decreasing consequently the antibiotic activity of treated waters.
Collapse
Affiliation(s)
- Xuexiang He
- Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012, United States; Department of Civil and Environmental Engineering and Nireas-International Water Research Centre, School of Engineering, University of Cyprus, PO Box 20537, 1678 Nicosia, Cyprus
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840, United States
| | - Irene Michael
- Department of Civil and Environmental Engineering and Nireas-International Water Research Centre, School of Engineering, University of Cyprus, PO Box 20537, 1678 Nicosia, Cyprus
| | - Despo Fatta-Kassinos
- Department of Civil and Environmental Engineering and Nireas-International Water Research Centre, School of Engineering, University of Cyprus, PO Box 20537, 1678 Nicosia, Cyprus
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012, United States; Department of Civil and Environmental Engineering and Nireas-International Water Research Centre, School of Engineering, University of Cyprus, PO Box 20537, 1678 Nicosia, Cyprus.
| |
Collapse
|
41
|
He X, Zhang G, de la Cruz AA, O'Shea KE, Dionysiou DD. Degradation mechanism of cyanobacterial toxin cylindrospermopsin by hydroxyl radicals in homogeneous UV/H₂O₂ process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:4495-4504. [PMID: 24625255 DOI: 10.1021/es403732s] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The degradation of cylindrospermopsin (CYN), a widely distributed and highly toxic cyanobacterial toxin (cyanotoxin), remains poorly elucidated. In this study, the mechanism of CYN destruction by UV-254 nm/H2O2 advanced oxidation process (AOP) was investigated by mass spectrometry. Various byproducts identified indicated three common reaction pathways: hydroxyl addition (+16 Da), alcoholic oxidation or dehydrogenation (-2 Da), and elimination of sulfate (-80 Da). The initiation of the degradation was observed at the hydroxymethyl uracil and tricyclic guanidine groups; uracil moiety cleavage/fragmentation and further ring-opening of the alkaloid were also noted at an extended reaction time or higher UV fluence. The degradation rates of CYN decreased and less byproducts (species) were detected using natural water matrices; however, CYN was effectively eliminated under extended UV irradiation. This study demonstrates the efficiency of CYN degradation and provides a better understanding of the mechanism of CYN degradation by hydroxyl radical, a reactive oxygen species that can be generated by most AOPs and is present in natural water environment.
Collapse
Affiliation(s)
- Xuexiang He
- Environmental Engineering and Science Program, University of Cincinnati , Cincinnati, Ohio 45221-0012, United States
| | | | | | | | | |
Collapse
|