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Wei N, Hu C, Dittmann E, Song L, Gan N. The biological functions of microcystins. WATER RESEARCH 2024; 262:122119. [PMID: 39059200 DOI: 10.1016/j.watres.2024.122119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024]
Abstract
Microcystins are potent hepatotoxins predominantly produced by bloom-forming freshwater cyanobacteria (e.g., Microcystis, Planktothrix, Dolichospermum). Microcystin biosynthesis involves large multienzyme complexes and tailoring enzymes encoded by the mcy gene cluster. Mutation, recombination, and deletion events have shaped the mcy gene cluster in the course of evolution, resulting in a large diversity of microcystin congeners and the natural coexistence of toxic and non-toxic strains. The biological functions of microcystins and their association with algal bloom formation have been extensively investigated over the past decades. This review synthesizes recent advances in decoding the biological role of microcystins in carbon/nitrogen metabolism, antioxidation, colony formation, and cell-to-cell communication. Microcystins appear to adopt multifunctional roles in cyanobacteria that reflect the adaptive plasticity of toxic cyanobacteria to changing environments.
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Affiliation(s)
- Nian Wei
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
| | - Chenlin Hu
- College of Pharmacy, University of Houston, Houston, TX 77204, USA
| | - Elke Dittmann
- Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany
| | - Lirong Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Nanqin Gan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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2
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Reid N, Reyne MI, O'Neill W, Greer B, He Q, Burdekin O, McGrath JW, Elliott CT. Unprecedented Harmful algal bloom in the UK and Ireland's largest lake associated with gastrointestinal bacteria, microcystins and anabaenopeptins presenting an environmental and public health risk. ENVIRONMENT INTERNATIONAL 2024; 190:108934. [PMID: 39106632 DOI: 10.1016/j.envint.2024.108934] [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: 04/30/2024] [Revised: 07/31/2024] [Accepted: 08/01/2024] [Indexed: 08/09/2024]
Abstract
Harmful Algal Blooms (HABs) are outbreaks of aquatic toxic microalgae emerging as a global problem driven by nutrient enrichment, global climate change and invasive species. We uniquely describe a HAB of unprecedented duration, extent and magnitude during 2023 in Lough Neagh; the UK and Ireland's largest freshwater lake, using an unparalleled combination of satellite imagery, nutrient analysis, 16S rRNA gene sequencing and cyanotoxin profiling. The causative agent Microcystis aeruginosa accounted for over a third of DNA in water samples though common bacterioplankton species also bloomed. Water phosphate levels were hypertrophic and drove local algal biomass. The HAB pervaded the entire ecosystem with algal mats accumulating around jetties, marinas and lock gates. Over 80 % of bacterial DNA isolated from algal mat samples consisted of species associated with wildfowl or livestock faeces and human-effluent wastewater including 13 potential pathogens that can cause serious human illness including: E. coli, Salmonella, Enterobacter and Clostridium among others. Ten microcystins, nodularin and two anabaenopeptin toxins were confirmed as present (with a further microcystin and four anabaenopeptins suspected), with MC-RR and -LR in high concentrations at some locations (1,137-18,493 μg/L) with MC-LR exceeding World Health Organisation (WHO) recreational exposure guidelines in all algal mats sampled. This is the first detection of anabaenopeptins in any waterbody on the island of Ireland. Notwithstanding the ecological impacts, this HAB represented an environmental and public health risk, curtailing recreational activities in-and-around the lake and damaging local businesses. Reducing agricultural runoff and discharge from human-effluent wastewater treatment to manage nutrient loading, and the public health risk, should be the top priority of stakeholders, especially government. Key recommendations include Nature-based Solutions that avoid conflict with the productivity and profitability of the farming sector enhancing sustainability. We hope this stimulates real-world action to resolve the problems besetting this internationally important ecosystem.
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Affiliation(s)
- Neil Reid
- Institute of Global Food Security (IGFS), School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, UK.
| | - Marina I Reyne
- Institute of Global Food Security (IGFS), School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, UK
| | - William O'Neill
- Institute of Global Food Security (IGFS), School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, UK
| | - Brett Greer
- Institute of Global Food Security (IGFS), School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, UK; International Joint Research Center on Food Security (IJC-FOODSEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani 12120, Thailand
| | - Qiqi He
- Institute of Global Food Security (IGFS), School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, UK; International Joint Research Center on Food Security (IJC-FOODSEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani 12120, Thailand
| | - Oliver Burdekin
- Department for Continuing Education, University of Oxford, Rewley House, 1 Wellington Square, Oxford OX1 2JA, UK
| | - John W McGrath
- Institute of Global Food Security (IGFS), School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, UK
| | - Chris T Elliott
- Institute of Global Food Security (IGFS), School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland, UK; International Joint Research Center on Food Security (IJC-FOODSEC), 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, Pathum Thani 12120, Thailand
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3
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Arruda RS, Jacinavicius FR, Noyma NP, Drummond E, Barreto DA, da Silva LHS, Huszar VL, Pinto E, Lürling M, Marinho MM. Cyanopeptides occurrence and diversity in a Brazilian tropical reservoir: Exploring relationships with water quality. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 351:124051. [PMID: 38688388 DOI: 10.1016/j.envpol.2024.124051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/02/2024]
Abstract
Microcystins (MCs) are a class of toxic secondary metabolites produced by some cyanobacteria strains that endanger aquatic and terrestrial organisms in various freshwater systems. Although patterns in MC occurrence are being recognized, divergences in the global data still hamper our ability to predict the toxicity of cyanobacterial blooms. This study aimed (i) to determine the dynamics of MCs and other cyanopeptides in a tropical reservoir, (ii) to investigate the correlation between peptides and potential cyanotoxin producers (iii) identifying the possible abiotic factors that influence the peptides. We analyzed, monthly, eight MC variants (MC-RR, -LA, -LF, -LR, -LW, -YR, [D-Asp3]-RR and [D-Asp3]-LR) and other peptides in 47 water samples collected monthly, all season long, from two sampling sites in a tropical eutrophic freshwater reservoir, in southeastern Brazil. The cyanopeptides were assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The biomass of potential cyanobacterial producers and water quality variables were measured. MCs were detected in both sampling sites year-round; the total MC concentration varied from 0.21 to 4.04 μg L-1, and three MC variants were identified and quantified (MC-RR, [D-Asp3]-RR, -LR). Additionally, we identified 28 compounds belonging to three other cyanopeptide classes: aeruginosin, microginin, and cyanopeptolin. As potential MC producers, Microcystis spp. and Dolichospermum circinalis were dominant during the study, representing up to 75% of the total phytoplankton. Correlational and redundancy analysis suggested positive effects of dissolved oxygen, nitrate, and total phosphorus on MC and microginins concentration, while water temperature appeared to favor aeruginosins. A comparison between our results and historical data showed a reduction in total phosphorus and cyanobacteria, suggesting increased water quality in the reservoir. However, the current MC concentrations indicate a rise in cyanobacterial toxicity over the last eight years. Moreover, our study underscores the pressing need to explore cyanopeptides other than MCs in tropical aquatic systems.
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Affiliation(s)
- Renan Silva Arruda
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil.
| | - Fernanda Rios Jacinavicius
- Department of Clinical Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 580 - Bloco 17, São Paulo, SP, 05508-000, Brazil
| | - Natália Pessoa Noyma
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil
| | - Erick Drummond
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil
| | - Davi Almeida Barreto
- Laboratory of Phycology, National Museum, Federal University of Rio de Janeiro - UFRJ, Quinta da Boa Vista, São Cristóvão, CEP, 20940-040, Rio de Janeiro, RJ, Brazil
| | - Lúcia Helena Sampaio da Silva
- Laboratory of Phycology, National Museum, Federal University of Rio de Janeiro - UFRJ, Quinta da Boa Vista, São Cristóvão, CEP, 20940-040, Rio de Janeiro, RJ, Brazil
| | - Vera Lucia Huszar
- Laboratory of Phycology, National Museum, Federal University of Rio de Janeiro - UFRJ, Quinta da Boa Vista, São Cristóvão, CEP, 20940-040, Rio de Janeiro, RJ, Brazil
| | - Ernani Pinto
- Centre for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário, 303, São Dimas, Piracicaba, SP, 13416-000, Brazil
| | - Miquel Lürling
- Aquatic Ecology & Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700, AA, Wageningen, the Netherlands
| | - Marcelo Manzi Marinho
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil
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4
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Kwidzińska K, Zalewska M, Aksmann A, Kobos J, Mazur-Marzec H, Caban M. Multi-biomarker response of cyanobacteria Synechocystis salina and Microcystis aeruginosa to diclofenac. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134373. [PMID: 38678710 DOI: 10.1016/j.jhazmat.2024.134373] [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: 12/04/2023] [Revised: 02/14/2024] [Accepted: 04/19/2024] [Indexed: 05/01/2024]
Abstract
The cyanobacterial response to pharmaceuticals is less frequently investigated compared to green algae. Pharmaceuticals can influence not only the growth rate of cyanobacteria culture, but can also cause changes at the cellular level. The effect of diclofenac (DCF) as one of the for cyanobacteria has been rarely tested, and DCF has never been applied with cellular biomarkers. The aim of this work was to test the response of two unicellular cyanobacteria (Synechocystis salina and Microcystis aeruginosa) toward DCF (100 mg L-1) under photoautotrophic growth conditions. Such endpoints were analyzed as cells number, DCF uptake, the change in concentrations of photosynthetic pigments, the production of toxins, and chlorophyll a in vivo fluorescence. It was noted that during a 96 h exposure, cell proliferation was not impacted. Nevertheless, a biochemical response was observed. The increased production of microcystin was noted for M. aeruginosa. Due to the negligible absorption of DCF into cells, it is possible that the biochemical changes are induced by an external signal. The application of non-standard biomarkers demonstrates the effect of DCF on microorganism metabolism without a corresponding effect on biomass. The high resistance of cyanobacteria to DCF and the stimulating effect of DCF on the secretion of toxins raise concerns for environment biodiversity.
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Affiliation(s)
- Klaudia Kwidzińska
- University of Gdansk, Faculty of Chemistry, Department of Environmental Analysis, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
| | - Martyna Zalewska
- University of Gdansk, Faculty of Biology, Department of Plant Experimental Biology and Biotechnology, ul. Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Anna Aksmann
- University of Gdansk, Faculty of Biology, Department of Plant Experimental Biology and Biotechnology, ul. Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Justyna Kobos
- University of Gdansk, Faculty of Oceanography and Geography, Department of Marine Biology and Biotechnology, al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Hanna Mazur-Marzec
- University of Gdansk, Faculty of Oceanography and Geography, Department of Marine Biology and Biotechnology, al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Magda Caban
- University of Gdansk, Faculty of Chemistry, Department of Environmental Analysis, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
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5
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Kianian I, Mottaqi M, Mohammadipanah F, Sajedi H. Automated identification of toxigenic cyanobacterial genera for water quality control purposes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 362:121274. [PMID: 38838537 DOI: 10.1016/j.jenvman.2024.121274] [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: 09/06/2023] [Revised: 04/27/2024] [Accepted: 05/26/2024] [Indexed: 06/07/2024]
Abstract
Cyanobacteria are the dominating microorganisms in aquatic environments, posing significant risks to public health due to toxin production in drinking water reservoirs. Traditional water quality assessments for abundance of the toxigenic genera in water samples are both time-consuming and error-prone, highlighting the urgent need for a fast and accurate automated approach. This study addresses this gap by introducing a novel public dataset, TCB-DS (Toxigenic Cyanobacteria Dataset), comprising 2593 microscopic images of 10 toxigenic cyanobacterial genera and subsequently, an automated system to identify these genera which can be divided into two parts. Initially, a feature extractor Convolutional Neural Network (CNN) model was employed, with MobileNet emerging as the optimal choice after comparing it with various other popular architectures such as MobileNetV2, VGG, etc. Secondly, to perform classification algorithms on the extracted features of the first section, multiple approaches were tested and the experimental results indicate that a Fully Connected Neural Network (FCNN) had the optimal performance with weighted accuracy and f1-score of 94.79% and 94.91%, respectively. The highest macro accuracy and f1-score were 90.17% and 87.64% which were acquired using MobileNetV2 as the feature extractor and FCNN as the classifier. These results demonstrate that the proposed approach can be employed as an automated screening tool for identifying toxigenic Cyanobacteria with practical implications for water quality control replacing the traditional estimation given by the lab operator following microscopic observations. The dataset and code of this paper are publicly available at https://github.com/iman2693/CTCB.
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Affiliation(s)
- Iman Kianian
- Department of Computer Science, School of Mathematics, Statistics and Computer Science, College of Science, University of Tehran, Tehran, Iran.
| | | | - Fatemeh Mohammadipanah
- Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, 14155-6455, Tehran, Iran.
| | - Hedieh Sajedi
- Department of Computer Science, School of Mathematics, Statistics and Computer Science, College of Science, University of Tehran, Tehran, Iran.
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6
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Chen T, Zhang H, Dong W, Bu K, Chen X. Toxin production and transcriptomic response to nitrate concentrations in the toxic dinoflagellate Alexandrium tamarense. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106550. [PMID: 38820827 DOI: 10.1016/j.marenvres.2024.106550] [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: 11/06/2023] [Revised: 04/22/2024] [Accepted: 05/09/2024] [Indexed: 06/02/2024]
Abstract
The bloom-forming dinoflagellate Alexandrium tamarense is one of the most important producers of paralytic shellfish poisoning toxins. Annually recurrent blooms of this dinoflagellate species is associated with the incremental nitrogen influx, especially excessive nitrate input. However, limited studies have been conducted on the toxin production and underlying molecular regulation mechanisms of A. tamarense under various nitrate (N) conditions. Therefore, toxin production and transcriptomic responses of this species were investigated. The toxin profile of A. tamarense was consistently dominated by the C2-toxins, and the cellular toxicity increased with N concentrations peaking at 9.23 ± 0.03 fmol/cell in the 883 μM N-added group. Under lower N conditions, expressions of two STX-core genes, sxtA and sxtG, were significantly down-regulated, suggesting that N regulated sxt expression and triggered responses related to toxin biosynthesis. Results of this study provided valuable insights into the ecophysiology of A. tamarense, enhancing our understanding of the occurrence of toxification events in natural environments.
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Affiliation(s)
- Tiantian Chen
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Qingdao, 266100, China
| | - Han Zhang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Qingdao, 266100, China
| | - Wenlong Dong
- Shandong Marine Forecast and Hazard Mitigation Service, Qingdao, 266100, China
| | - Kexin Bu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Qingdao, 266100, China
| | - Xi Chen
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
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7
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Teng J, Xu Q, Zhang H, Yu R, Liu C, Song M, Cao X, Du X, Tao S, Yan H. Enzymatic mechanism of MlrB for catalyzing linearized microcystins by Sphingopyxis sp. USTB-05. Front Microbiol 2024; 15:1389235. [PMID: 38711965 PMCID: PMC11070527 DOI: 10.3389/fmicb.2024.1389235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 04/08/2024] [Indexed: 05/08/2024] Open
Abstract
Microcystins (MCs) are the most widespread cyanobacterial toxins in eutrophic water body. As high toxic intermediate metabolites, linearized MCs are further catalyzed by linearized microcystinase (MlrB) of Sphingopyxis sp. USTB-05. Here MlrB structure was studied by comprizing with a model representative of the penicillin-recognizing enzyme family via homology modeling. The key active sites of MlrB were predicted by molecular docking, and further verified by site-directed mutagenesis. A comprehensive enzymatic mechanism for linearized MCs biodegradation by MlrB was proposed: S77 transferred a proton to H307 to promote a nucleophilic attack on the peptide bond (Ala-Leu in MC-LR or Ala-Arg in MC-RR) of linearized MCs to form the amide intermediate. Then water was involved to break the peptide bond and produced the tetrapeptide as product. Meanwhile, four amino acid residues (K80, Y171, N173 and D245) acted synergistically to stabilize the substrate and intermediate transition states. This study firstly revealed the enzymatic mechanism of MlrB for biodegrading linearized MCs with both computer simulation and experimental verification.
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Affiliation(s)
- Junhui Teng
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Qianqian Xu
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Haiyang Zhang
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Ruipeng Yu
- Beijing Institute for Drug Control, Beijing, China
| | - Chao Liu
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Meijie Song
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Xiaoyu Cao
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Xinyue Du
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Suxuan Tao
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
| | - Hai Yan
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, China
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Reignier O, Bormans M, Hervé F, Robert E, Savar V, Tanniou S, Amzil Z, Noël C, Briand E. Spatio-temporal connectivity of a toxic cyanobacterial community and its associated microbiome along a freshwater-marine continuum. HARMFUL ALGAE 2024; 134:102627. [PMID: 38705620 DOI: 10.1016/j.hal.2024.102627] [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: 01/26/2024] [Revised: 03/22/2024] [Accepted: 04/10/2024] [Indexed: 05/07/2024]
Abstract
Due to climate changes and eutrophication, blooms of predominantly toxic freshwater cyanobacteria are intensifying and are likely to colonize estuaries, thus impacting benthic organisms and shellfish farming representing a major ecological, health and economic risk. In the natural environment, Microcystis form large mucilaginous colonies that influence the development of both cyanobacterial and embedded bacterial communities. However, little is known about the fate of natural colonies of Microcystis by salinity increase. In this study, we monitored the fate of a Microcystis dominated bloom and its microbiome along a French freshwater-marine gradient at different phases of a bloom. We demonstrated changes in the cyanobacterial genotypic composition, in the production of specific metabolites (toxins and compatible solutes) and in the heterotrophic bacteria structure in response to the salinity increase. In particular M. aeruginosa and M. wesenbergii survived salinities up to 20. Based on microcystin gene abundance, the cyanobacteria became more toxic during their estuarine transfer but with no selection of specific microcystin variants. An increase in compatible solutes occurred along the continuum with extensive trehalose and betaine accumulations. Salinity structured most the heterotrophic bacteria community, with an increased in the richness and diversity along the continuum. A core microbiome in the mucilage-associated attached fraction was highly abundant suggesting a strong interaction between Microcystis and its microbiome and a likely protecting role of the mucilage against an osmotic shock. These results underline the need to better determine the interactions between the Microcystis colonies and their microbiome as a likely key to their widespread success and adaptation to various environmental conditions.
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Affiliation(s)
| | - Myriam Bormans
- UMR CNRS 6553 ECOBIO, University of Rennes 1, Rennes F-35042, France
| | - Fabienne Hervé
- IFREMER, PHYTOX, Laboratoire METALG, Nantes F-44000, France
| | - Elise Robert
- IFREMER, PHYTOX, Laboratoire GENALG, Nantes F-44000, France
| | | | - Simon Tanniou
- IFREMER, PHYTOX, Laboratoire METALG, Nantes F-44000, France
| | - Zouher Amzil
- IFREMER, PHYTOX, Laboratoire METALG, Nantes F-44000, France
| | - Cyril Noël
- IFREMER, IRSI - Service de Bioinformatique (SeBiMER), Plouzané, France
| | - Enora Briand
- IFREMER, PHYTOX, Laboratoire GENALG, Nantes F-44000, France.
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9
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Anam GB, Ahn YH. The interplay of low H 2O 2 doses, lytic cyanophage, and Microcystis aeruginosa: Implications for cyanobacterial bloom control and microcystin production/release. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170327. [PMID: 38266727 DOI: 10.1016/j.scitotenv.2024.170327] [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: 09/12/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 01/26/2024]
Abstract
Low H2O2 doses can suppress cyanobacterial blooms without damaging non-target species but enable undesirable regrowth. Besides, the role of cyanophage in preventing regrowth after low H2O2 exposure remains unclear. Applying phages to cyanobacteria pre-exposed to low H2O2 in early growth stages may improve host removal and reduce microcystin (MC) production/release. Lytic cyanophage MDM-1 with a 172 PFU/cell burst size, 2-day short latent period against MCs-producing Microcystis, shows high H2O2 stability. Low H2O2 (1 to 2.5 mg/L) doses significantly (p < 0.05) inhibited Microcystis aeruginosa growth rate, biofilm and MCs concentration reduction in a dose-dependent manner but regrowth occurred at all concentrations. Phage treatment eliminated cells without H2O2 pretreatment within 3 days and reduced MC production. H2O2-pretreated M. aeruginosa cells altered the phage dynamics, affecting adsorption, latency, production, and cell lysis in response to H2O2-induced oxidative stress. At 1.5 mg H2O2/L pretreatment, cells were eliminated with reduced MC production, like untreated cells. H2O2 pretreatment with 2.0 and 2.5 mg/L resulted in an extension of the phage absorption phase and the latent period. This was accompanied by a reduction in lysis efficacy, attributed to the increased ROS production. At 2.5 mg H2O2/L, 17.10 % of phages remain un-adsorbed, with cell lysis rate dropped from 0.89 d-1 to 0.26 d-1 compared to the untreated control. The highest phage titer (70 %) was obtained with 1.5 mg/H2O2 pretreated cells. This study emphasizes that low-dose H2O2 eliminates Microcystis but severely affects phage lysis and MCs release depending on H2O2-induced ROS levels. It is a crucial consideration when using phages to control cyanobacterial blooms with H2O2-induced stress.
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Affiliation(s)
- Giridhar Babu Anam
- Department of Civil Engineering, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea.
| | - Young-Ho Ahn
- Department of Civil Engineering, Yeungnam University, Gyeongsan 38541, Gyeongbuk, Republic of Korea.
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10
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Yin L, Xu L, Shi K, Chen W, Zhang Y, Wang J, An J, He H, Yang S, Ni L, Li S. Physiology, microcystin production, and transcriptomic responses of Microcystis aeruginosa exposed to calcium and magnesium. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169786. [PMID: 38181954 DOI: 10.1016/j.scitotenv.2023.169786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 01/07/2024]
Abstract
Calcium ions (Ca2+) and magnesium ions (Mg2+) are pivotal in the community composition and stability of harmful cyanobacteria, yet the physiological and molecular responses remains poorly understood. This study aims to explore these responses in the high microcystin producer Microcystis aeruginosa (M. aeruginosa). Results indicate that the growth of M. aeruginosa is inhibited by Ca2+/Mg2+ exposure (0.5-10 mM), while Fv/Fm photosynthetic parameters and extracellular microcystin-leucine-arginine (MC-LR) concentrations increase. Additionally, MC-LR release is significantly elevated under exposure to Ca2+/Mg2+, posing potential aquatic environmental risks. Transcriptomic analysis reveals downregulation of genes related to cell architecture, membrane transport, and metabolism, while the genes linked to photosynthesis electron transmission and heavy metal-responsive transcriptional regulators are upregulated to adapt to environmental changes. Further analysis reveals that Ca2+ and Mg2+ primarily impact sulfur metabolism and transport of amino acids and mineral within cells. These findings provide insights into M. aeruginosa cells responses to Ca2+ and Mg2+ exposure.
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Affiliation(s)
- Li Yin
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Lin Xu
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Kaipian Shi
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Weiyu Chen
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Yong Zhang
- Department of Geological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Juan Wang
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Junfeng An
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Huan He
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Shaogui Yang
- School of Environment, Nanjing Normal University, Nanjing 210023, China
| | - Lixiao Ni
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, School of Environment, Hohai University, Nanjing 210098, China
| | - Shiyin Li
- School of Environment, Nanjing Normal University, Nanjing 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China.
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11
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Kiledal EA, Reitz LA, Kuiper EQ, Evans J, Siddiqui R, Denef VJ, Dick GJ. Comparative genomic analysis of Microcystis strain diversity using conserved marker genes. HARMFUL ALGAE 2024; 132:102580. [PMID: 38331539 DOI: 10.1016/j.hal.2024.102580] [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: 04/25/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 02/10/2024]
Abstract
Microcystis-dominated cyanobacterial harmful algal blooms (cyanoHABs) have a global impact on freshwater environments, affecting both wildlife and human health. Microcystis diversity and function in field samples and laboratory cultures can be determined by sequencing whole genomes of cultured isolates or natural populations, but these methods remain computationally and financially expensive. Amplicon sequencing of marker genes is a lower cost and higher throughput alternative to characterize strain composition and diversity in mixed samples. However, the selection of appropriate marker gene region(s) and primers requires prior understanding of the relationship between single gene genotype, whole genome content, and phenotype. To identify phylogenetic markers of Microcystis strain diversity, we compared phylogenetic trees built from each of 2,351 individual core genes to an established phylogeny and assessed the ability of these core genes to predict whole genome content and bioactive compound genotypes. We identified single-copy core genes better able to resolve Microcystis phylogenies than previously identified marker genes. We developed primers suitable for current Illumina-based amplicon sequencing with near-complete coverage of available Microcystis genomes and demonstrate that they outperform existing options for assessing Microcystis strain composition. Results showed that genetic markers can be used to infer Microcystis gene content and phenotypes such as potential production of bioactive compounds , although marker performance varies by bioactive compound gene and sequence similarity. Finally, we demonstrate that these markers can be used to characterize the Microcystis strain composition of laboratory or field samples like those collected for surveillance and modeling of Microcystis-dominated cyanobacterial harmful algal blooms.
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Affiliation(s)
- E Anders Kiledal
- Department of Earth and Environmental Sciences, University of Michigan, 2534 North University Building, 1100 North University Avenue Ave, Rm. 2004, Ann Arbor, MI 48109-1005, USA.
| | - Laura A Reitz
- Department of Earth and Environmental Sciences, University of Michigan, 2534 North University Building, 1100 North University Avenue Ave, Rm. 2004, Ann Arbor, MI 48109-1005, USA
| | - Esmée Q Kuiper
- Department of Earth and Environmental Sciences, University of Michigan, 2534 North University Building, 1100 North University Avenue Ave, Rm. 2004, Ann Arbor, MI 48109-1005, USA
| | - Jacob Evans
- Department of Ecology and Evolutionary Biology, University of Michigan, 2220 Biological Sciences Building, 1105 North University Avenue, Ann Arbor, MI 48109-1005, USA
| | - Ruqaiya Siddiqui
- Microbiome Core, University of Michigan, 1500 MSRB 1, 1150W Medical Center Drive, Ann Arbor, MI 48109-5666, USA
| | - Vincent J Denef
- Department of Ecology and Evolutionary Biology, University of Michigan, 2220 Biological Sciences Building, 1105 North University Avenue, Ann Arbor, MI 48109-1005, USA
| | - Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, 2534 North University Building, 1100 North University Avenue Ave, Rm. 2004, Ann Arbor, MI 48109-1005, USA; Cooperative Institute for Great Lakes Research, University of Michigan, 4040 Dana Building, 440 Church Street, Ann Arbor, MI 48109-1041, USA
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12
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Manjitha KGL, Sewwandi BGN. Cyanotoxins availability and detection methods in wastewater treatment plants: A review. J Microbiol Methods 2024; 217-218:106886. [PMID: 38159650 DOI: 10.1016/j.mimet.2023.106886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 12/06/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
Research interest in ecological significance, toxicity, and potential applications of cyanobacterial metabolites has grown as a result of the current extensive cyanobacterial blooms in water bodies. Under favourable conditions, specific cyanobacterial species release cyanotoxins, hepatotoxins, dermatoxins, neurotoxins, and cytotoxins, creating a heightened threat to aquatic ecosystems and human health. Wastewater treatment plants (WWTPs) offer one of the best culture media for cyanobacterial development and synthesis of cyanotoxins by providing optimum environmental conditions, including temperature, light intensity, lengthy water residence time, and nutrient-rich habitat. To discover the intricate relationships between cyanobacterial populations and other living organisms, it is important to comprehend the cyanobacterial communities in the ecology of WWTPs. Monitoring strategies of these cyanotoxins typically involved combined assessments of biological, biochemical, and physicochemical methodologies. Microscopic observations and physicochemical factors analysis cannot be carried out for toxicity potential analysis of blooms. Due to their high sensitivity, molecular-based approaches allow for the early detection of toxic cyanobacteria, while biological analysis is carried out by using water bloom material and cell extracts to screen cyanotoxins build up in organisms. As each approach has benefits and drawbacks, the development of an integrated multi-method laboratory system is essential to obtain trustworthy results and accurate detection of cyanotoxin levels in WWTPs allowing us to take necessary proactive and preventative approaches for effective wastewater treatment.
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Affiliation(s)
- K G L Manjitha
- Faculty of Graduate Studies, University of Kelaniya, Kelaniya 11600, Sri Lanka
| | - B G N Sewwandi
- Department of Zoology and Environmental Management, Faculty of Science, University of Kelaniya, Kelaniya 11600, Sri Lanka.
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13
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Meng X, Ban M, Wu Z, Huang L, Wang Z, Cheng Y. Morchella Effectively Removes Microcystins Produced by Microcystis aeruginosa. Microbes Environ 2024; 39:ME23101. [PMID: 38763742 PMCID: PMC11220450 DOI: 10.1264/jsme2.me23101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/19/2024] [Indexed: 05/21/2024] Open
Abstract
Microcystins (MCs) produced by Microcystis aeruginosa are harmful to animal and human health, and there is currently no effective method for their removal. Therefore, the development of biological approaches that inhibit cyanobacteria and remove MCs is needed. We identified strain MB1, confirmed as Morchella, using morphological and mole-cular evolution methods. To assess the impact of strain MB1 on M. aeruginosa, we conducted an experiment in which we inoculated M. aeruginosa with Morchella strain MB1. After their co-cultivation for 4 d, the inoculation with 0.9696 g MB1 completely inhibited and removed M. aeruginosa while concurrently removing up to 95% of the MC content. Moreover, within 3 d of their co-cultivation, MB1 removed more than 50% of nitrogen and phosphorus from the M. aeruginosa solution. Therefore, the development of effective biological techniques for MC removal is paramount in safeguarding both the environment and human well-being. We herein successfully isolated MB1 from its natural habitat. This strain effectively inhibited and removed M. aeruginosa and also reduced the content of nitrogen and phosphorus in the M. aeruginosa solution. Most importantly, it exhibited a robust capability to eliminate MCs. The present results offer a new method and technical reference for mitigating harmful algal blooms.
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Affiliation(s)
- Xinchao Meng
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping 136000, China
| | - Meihan Ban
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping 136000, China
| | - Zhaoyang Wu
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping 136000, China
| | - Lilong Huang
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping 136000, China
| | - Zicheng Wang
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, United States
| | - Yunqing Cheng
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping 136000, China
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14
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Jia Y, Huang Y, Ma J, Zhang S, Liu J, Li T, Song L. Toxicity of the disinfectant benzalkonium chloride (C 14) towards cyanobacterium Microcystis results from its impact on the photosynthetic apparatus and cell metabolism. J Environ Sci (China) 2024; 135:198-209. [PMID: 37778795 DOI: 10.1016/j.jes.2022.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/07/2022] [Accepted: 11/07/2022] [Indexed: 10/03/2023]
Abstract
Quaternary ammonium compounds (QACs) are commonly used in a variety of consumer and commercial products, typically as a component of disinfectants. During the COVID-19 pandemic, QACs became one of the primary agents utilized to inactivate the SARS-CoV-2 virus on surfaces. However, the ecotoxicological effects of QACs upon aquatic organisms have not been fully assessed. In this study, we examined the effects of a widely used QAC (benzalkonium chloride-C14, BAC-14) on two toxigenic Microcystis strains and one non-toxigenic freshwater Microcystis strain and carried out an analysis focused on primary, adaptive and compensatory stress responses at apical (growth and photosynthesis) and metabolic levels. This analysis revealed that the two toxic Microcystis strains were more tolerant than the non-toxic strain, with 96 hr-EC50 values of 0.70, 0.76, and 0.38 mg/L BAC-14 for toxigenic M. aeruginosa FACHB-905, toxigenic M. aeruginosa FACHB-469, and non-toxigenic M. wesenbergii FACHB-908, respectively. The photosynthetic activities of the Microcystis, assessed via Fv/Fm values, were significantly suppressed under 0.4 mg/L BAC-14. Furthermore, this analysis revealed that BAC-14 altered 14, 12, and 8 metabolic pathways in M. aeruginosa FACHB-905, M. aeruginosa FACHB-469, and M. wesenbergii FACHB-908, respectively. It is noteworthy that BAC-14 enhanced the level of extracellular microcystin production in the toxigenic Microcystis strains, although cell growth was not significantly affected. Collectively, these data show that BAC-14 disrupted the physiological and metabolic status of Microcystis cells and stimulated the production and release of microcystin, which could result in damage to aquatic systems.
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Affiliation(s)
- Yunlu Jia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Yi Huang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Jin Ma
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Shangwei Zhang
- Advanced Interdisciplinary Institute of Environment and Ecology, Beijing Normal University, Zhuhai 519087, China
| | - Jin Liu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Tianli Li
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Lirong Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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15
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Gomaa MN, Carmichael WW. The Role of Heterocysts in Cyanotoxin Production during Nitrogen Limitation. Toxins (Basel) 2023; 15:611. [PMID: 37888642 PMCID: PMC10610833 DOI: 10.3390/toxins15100611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/02/2023] [Accepted: 10/10/2023] [Indexed: 10/28/2023] Open
Abstract
Cyanobacteria harmful algal blooms (cyanoHABs) can have impacts on human health, aquatic ecosystems, and the economy. Nutrient management is an important mitigation and even remediation strategy. In this work, the paralytic shellfish toxin (PST)-producing Aphanizomenon (Aphan.) flos-aquae (Linnaeus) Ralfs ex Bornet & Flahault (now identified as Aphan. sp.) single filament isolate NH-5 was grown in P-depleted media, N-depleted media, and complete BG-11 media. Growth and heterocyst and vegetative cells were monitored using dry weight and cell counts. Ultrasonication was used to separate heterocysts from vegetative cells. HPLC-FLD with post-column derivatization was used to determine the saxitoxin (STX) and neosaxitoxin (NEOSTX) concentration per cell. Aphan. sp. NH-5 biomass was lower in the P-depleted media than in the N-depleted media and the control, though higher heterocyst counts were detected in the N-depleted media. The heterocyst toxin concentration was significantly higher compared to the vegetative cells for the N-depleted media, control, and P-depleted media. However, no significant differences were found among all preparations with regard to the STX-to-NEOSTX ratio. We conclude that N limitation induced higher heterocyst numbers and that N fixation activity is a factor behind the increase in the STX and NEOSTX production of Aphan. sp. NH-5.
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Affiliation(s)
- Mohamed N. Gomaa
- Department of Biochemistry, College of Science, University of Jeddah, Jeddah 21589, Saudi Arabia
| | - Wayne W. Carmichael
- Department Biological Sciences (Emeritus), Wright State University, Dayton, OH 45435, USA
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16
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Chen Q, Wang Z, Wei H, Wang J, Zhou W, Zhou P, Li D. Environmental concentrations of anionic surfactants in lake surface microlayers enhance the toxicity of Microcystis blooms: Insight from photosynthesis, interspecies competition, and MC production. WATER RESEARCH 2023; 244:120430. [PMID: 37678037 DOI: 10.1016/j.watres.2023.120430] [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: 06/06/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 09/09/2023]
Abstract
Anionic surfactants represented by linear alkylbenzene sulfonate (LAS) exhibit vertical heterogeneity of concentrations in aquatic environments owing to their amphiphilic structure. Field investigations showed that the concentration of anionic surfactants (mainly LAS) in the water surface microlayer (SML) of Lake Taihu reached 580 μg/L, higher than that in the lower layer. Floating Microcystis blooms overlap in space with the high concentration of anionic surfactants in SML. However, few studies have focused on the effects of anionic surfactants (e.g., LAS) on the interspecies competition between toxic and nontoxic Microcystis. In this study, coculture and monoculture experiments were conducted with both toxic and nontoxic Microcystis species to explore how the environmental concentration of LAS regulates the dominance of toxic Microcystis and toxicity from the perspective of photosynthesis, species dominance, and MC production. The results showed that LAS concentrations above 0.267 or 0.431 mg/L (depending on light conditions) selectively promoted the photosynthetic competitive advantage of toxic Microcystis, leading to its higher population proportion in the community. Additionally, LAS concentrations above 0.5 mg/L induced the synthesis and release of microcystins (MCs). The results of chlorophyll fluorescence analysis, electron microscopy and transcriptome sequencing suggested that compared with nontoxic Microcystis, toxic Microcystis can better resist LAS stress by dissipating excess light, maintaining an intact membrane structure and maintaining cellular homeostasis. Transcriptome sequencing revealed that the photosynthetic damage of nontoxic Microcystis might be attributed to the impacts of LAS on the absorption and assimilation of nitrogen, which finally resulted in the degradation of phycobilisomes. This study can provide novel insight for establishing standards and safety management of wastewater discharge.
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Affiliation(s)
- Qinyi Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Zhicong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China.
| | - Hui Wei
- Yulin Municipal Ecology and Environment Emergency and Technical Service Center, Yulin 537000, P.R. China
| | - Jinglong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Weicheng Zhou
- School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, P.R. China
| | - Panpan Zhou
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Dunhai Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China
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17
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Rahim NAA, Mohd Sidik Merican FM, Radzi R, Omar WMW, Nor SAM, Broady P, Convey P. Unveiling the Diversity of Periphytic Cyanobacteria (Cyanophyceae) from Tropical Mangroves in Penang, Malaysia. Trop Life Sci Res 2023; 34:57-94. [PMID: 37860087 PMCID: PMC10583846 DOI: 10.21315/tlsr2023.34.3.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 02/08/2023] [Indexed: 10/21/2023] Open
Abstract
Cyanobacteria are one of the most important groups of photoautotrophic organisms, contributing to carbon and nitrogen fixation in mangroves worldwide. They also play an important role in soil retention and stabilisation and contribute to high plant productivity through their secretion of plant growth-promoting substances. However, their diversity and distribution in Malaysian mangrove ecosystems have yet to be studied in detail, despite Malaysia hosting a significant element of remaining mangroves globally. In a floristic survey conducted in Penang, peninsular Malaysia, 33 morphospecies of periphytic cyanobacteria were identified and described for the first time from a mangrove ecosystem in Malaysia. Sixteen genera, comprising Aphanocapsa, Chroococcus, Chroococcidiopsis, Cyanobacterium, Desmonostoc, Geitlerinema, Leptolyngbya, Lyngbya, Microcystis, Myxosarcina, Oscillatoria, Phormidium, Pseudanabaena, Spirulina, Trichocoleus and Xenococcus, were obtained from field material growing on diverse natural and artificial substrata. Oscillatoriales was the dominant order with Phormidium the dominant genus at nine of the 15 sampling sites examined. Three of the morphospecies, Aphanocapsa cf. concharum, Xenococcus cf. pallidus and Oscillatoria pseudocurviceps, are rare and poorly known morphospecies worldwide. Chroococcus minutus, Phormidium uncinatum, P. amphigranulata, and some species of Oscillatoriales are considered as pollution indicator species. This study provides important baseline information for further investigation of the cyanobacterial microflora present in other mangrove areas around Malaysia. A complete checklist will enhance understanding of their ecological role and the potential for benefits arising from useful secondary metabolites or threats via toxin production to the ecosystem.
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Affiliation(s)
- Nur Afiqah Abdul Rahim
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM Pulau Pinang, Malaysia
| | | | - Ranina Radzi
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM Pulau Pinang, Malaysia
| | - Wan Maznah Wan Omar
- School of Biological Sciences, Universiti Sains Malaysia, 11800 USM Pulau Pinang, Malaysia
| | - Siti Azizah Mohd Nor
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu, 21300 Kuala Terengganu, Terengganu, Malaysia
| | - Paul Broady
- School of Biological Sciences, University of Canterbury, 20 Kirkwood Avenue, Upper Riccarton, Christchurch 8041, New Zealand
| | - Peter Convey
- British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom
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18
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Roy S, Guljamow A, Dittmann E. Impact of temperature on the temporal dynamics of microcystin in Microcystis aeruginosa PCC7806. Front Microbiol 2023; 14:1200816. [PMID: 37720143 PMCID: PMC10500830 DOI: 10.3389/fmicb.2023.1200816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/17/2023] [Indexed: 09/19/2023] Open
Abstract
Cyanobacterial blooms pose a serious threat to water quality and human health due to the production of the potent hepatotoxin microcystin. In microcystin-producing strains of the widespread genus Microcystis, the toxin is largely constitutively produced, but there are fluctuations between the cellular and extracellular pool and between free microcystin and protein-bound microcystin. Here we addressed the question of how different temperatures affect the growth and temporal dynamics of secondary metabolite production in the strain Microcystis aeruginosa PCC7806 and its microcystin-deficient ΔmcyB mutant. While the wild-type strain showed pronounced growth advantages at 20°C, 30°C, and 35°C, respectively, the ΔmcyB mutant was superior at 25°C. We further show that short-term incubations at 25°C-35°C result in lower amounts of freely soluble microcystin than incubations at 20°C and that microcystin congener ratios differ at the different temperatures. Subsequent assessment of the protein-bound microcystin pool by dot blot analysis and subcellular localization of microcystin using immunofluorescence microscopy showed re-localization of microcystin into the protein-bound pool combined with an enhanced condensation at the cytoplasmic membrane at temperatures above 25°C. This temperature threshold also applies to the condensate formation of the carbon-fixing enzyme RubisCO thereby likely contributing to reciprocal growth advantages of wild type and ΔmcyB mutant at 20°C and 25°C. We discuss these findings in the context of the environmental success of Microcystis at higher temperatures.
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Affiliation(s)
| | | | - Elke Dittmann
- Department of Microbiology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
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19
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Teng J, Song M, Xu Q, Zou Q, Zhang H, Yin C, Liu X, Liu Y, Yan H. Purification and Activity of the Second Recombinant Enzyme for Biodegrading Linearized Microcystins by Sphingopyxis sp. USTB-05. Toxins (Basel) 2023; 15:494. [PMID: 37624251 PMCID: PMC10467064 DOI: 10.3390/toxins15080494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/26/2023] [Accepted: 08/02/2023] [Indexed: 08/26/2023] Open
Abstract
Hepatotoxic microcystins (MCs) are produced and released by the harmful bloom-forming cyanobacteria, which severely threaten drinking water safety and human health due to their high toxicity, widespread distribution, and structural stability. The linearized microcystinase (MlrB) further hydrolyses the poisonous linearized MCs produced by the microcystinase-catalysed MCs to form tetrapeptides. Here, the purification and activity of MlrB were investigated. The results showed that the linearized products generated by 12.5 mg/L MC-LR and MC-RR were removed by purified recombinant MlrB at a protein concentration of 1 mg/L within 30 min. The high catalytic activity of MlrB can be obtained via heterologous expression and affinity purification, which lays the foundation for further studies on the properties and mechanism of MCs biodegradation enzymes.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Hai Yan
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China; (J.T.)
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20
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MacKeigan PW, Zastepa A, Taranu ZE, Westrick JA, Liang A, Pick FR, Beisner BE, Gregory-Eaves I. Microcystin concentrations and congener composition in relation to environmental variables across 440 north-temperate and boreal lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 884:163811. [PMID: 37121330 DOI: 10.1016/j.scitotenv.2023.163811] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/24/2023] [Accepted: 04/24/2023] [Indexed: 05/05/2023]
Abstract
Understanding the environmental conditions and taxa that promote the occurrence of cyanobacterial toxins is imperative for effective management of lake ecosystems. Herein, we modeled total microcystin presence and concentrations with a broad suite of environmental predictors and cyanobacteria community data collected across 440 Canadian lakes using standardized methods. We also conducted a focused analysis targeting 14 microcystin congeners across 190 lakes, to examine how abiotic and biotic factors influence their relative proportions. Microcystins were detected in 30 % of lakes, with the highest total concentrations occurring in the most eutrophic lakes located in ecozones of central Canada. The two most commonly detected congeners were MC-LR (61 % of lakes) and MC-LA (37 % of lakes), while 11 others were detected more sporadically across waterbodies. Congener diversity peaked in central Canada where cyanobacteria biomass was highest. Using a zero-altered hurdle model, the probability of detecting microcystin was best explained by increasing Microcystis biomass, Daphnia and cyclopoid biomass, soluble reactive phosphorus, pH and wind. Microcystin concentrations increased with the biomass of Microcystis and other less dominant cyanobacteria taxa, as well as total phosphorus, cyclopoid copepod biomass, dissolved inorganic carbon and water temperature. Collectively, these models accounted for 34 % and 70 % of the variability, respectively. Based on a multiple factor analysis of microcystin congeners, cyanobacteria community data, environmental and zooplankton data, we found that the relative abundance of most congeners varied according to trophic state and were related to a combination of cyanobacteria genera biomasses and environmental variables.
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Affiliation(s)
- Paul W MacKeigan
- Department of Biology, McGill University, Montreal, Quebec, Canada; Interuniversity Research Group in Limnology (GRIL), Quebec, Canada.
| | - Arthur Zastepa
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, Ontario, Canada
| | - Zofia E Taranu
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Montreal, Quebec, Canada
| | - Judy A Westrick
- Department of Chemistry, Wayne State University, Detroit, MI, United States
| | - Anqi Liang
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, Ontario, Canada
| | - Frances R Pick
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Beatrix E Beisner
- Interuniversity Research Group in Limnology (GRIL), Quebec, Canada; Department of Biological Sciences, University of Quebec at Montreal, Montreal, Quebec, Canada
| | - Irene Gregory-Eaves
- Department of Biology, McGill University, Montreal, Quebec, Canada; Interuniversity Research Group in Limnology (GRIL), Quebec, Canada
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21
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de Lima Pinheiro MM, Temponi Santos BL, Vieira Dantas Filho J, Perez Pedroti V, Cavali J, Brito dos Santos R, Oliveira Carreira Nishiyama AC, Guedes EAC, de Vargas Schons S. First monitoring of cyanobacteria and cyanotoxins in freshwater from fish farms in Rondônia state, Brazil. Heliyon 2023; 9:e18518. [PMID: 37520970 PMCID: PMC10374934 DOI: 10.1016/j.heliyon.2023.e18518] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/07/2023] [Accepted: 07/19/2023] [Indexed: 08/01/2023] Open
Abstract
The main aimed of this study was to evaluate the physicochemical parameters, abundance and density of cyanobacteria, determine their blooms and the ecotoxicological risk of their cyanotoxins in fish ponds water. This study was conducted out in 20 fish farms in Rondônia state (Brazilian Amazon), samplings were carried out in the rainy and dry seasons. The experiment was developed in a completely randomized factorial design 20 × 3 x 3 (20 fish farms, 3 ponds and 3 replications). Regarding the composition of qualitative samples, horizontal and vertical hauls were carried out on the water surface, quantitative samples was obtained using a plankton net (50 μm mesh opening). Meanwhile, with the use of a multiparametric probe, physicochemical analyzes in fish ponds water were carried out. Furthermore, the cyanobacteria found were classified taxonomically and its blooms were recorded. Finally, blood was collected from 60 Colossoma macropomum. Concerning the higher averages in the rainy season 6.13 mg L⁻1 of dissolved oxygen, 40.02 cm of transparency, 0.35 NO31⁻ of nitrate, 0.15 NO21⁻ of nitrite, 44.55 mg L⁻1 CaCO3 of alkalinity and 50.10 mg L⁻1 CaCO3 of hardness, while higher averages of pH, phosphate and phosphorus were found in the dry season. A total of 15 families and 29 species of cyanobacteria were identified in the different seasons. The families that showed the highest densities (rainy and dry seasons) were Microcystaceae (356 and 760 cells mL⁻1), Leptolyngbyaceae (126 and 287 cells mL⁻1) and Microcoleaceae (111 and 405 cells mL⁻1). The species that showed the highest densities were Microcystis aeruginosa (356 and 697 cells mL⁻1), Planktolyngbya limnetica (98 and 257 cells mL⁻1) and Planktothrix sp. (111 and 239 cells mL⁻1). There were significant Pearson's correlations (r > 0.85; p < 0.05) between family abundances and cyanotoxin volume between physicochemical water variables and seasonality. A total of 20 cyanobacteria blooms were recorded, all of which in the dry season showed an ecotoxicological risk. Concerning the assessment mutagenicity in fish blood cells, a total of 78 abnormalities per slide were observed. In the dry season, the expected volume of cyanotoxins in the ponds from fish farms F1 and F4 were above the quantification limit (>QL). Abundance and density of cyanobacteria and their blooms and cyanotoxins can be used as bioindicators of eutrophication and/or water quality and ecotoxicological risk in fish ponds.
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Affiliation(s)
| | | | | | - Vinícius Perez Pedroti
- Programa de Pós-Graduação Em Ciências Ambientais, Universidade Federal de Rondônia, Rolim de Moura, RO, Brazil
| | - Jucilene Cavali
- Programa de Pós-Graduação Em Sanidade e Produção Animal Sustentável Na Amazônia Ocidental, Universidade Federal Do Acre, Rio Branco, AC, Brazil
| | | | | | - Elica Amara Cecilia Guedes
- Centro de Ciências Agrárias e Instituto de Ciências Biológicas e da Saúde, Universidade Federal de Alagoas, Maceió, AL, Brazil
| | - Sandro de Vargas Schons
- Programa de Pós-Graduação Em Ciências Ambientais, Universidade Federal de Rondônia, Rolim de Moura, RO, Brazil
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22
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Bashir F, Bashir A, Bouaïcha N, Chen L, Codd GA, Neilan B, Xu WL, Ziko L, Rajput VD, Minkina T, Arruda RS, Ganai BA. Cyanotoxins, biosynthetic gene clusters, and factors modulating cyanotoxin biosynthesis. World J Microbiol Biotechnol 2023; 39:241. [PMID: 37394567 DOI: 10.1007/s11274-023-03652-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/17/2023] [Indexed: 07/04/2023]
Abstract
Cyanobacterial harmful algal blooms (CHABs) are a global environmental concern that encompasses public health issues, water availability, and water quality owing to the production of various secondary metabolites (SMs), including cyanotoxins in freshwater, brackish water, and marine ecosystems. The frequency, extent, magnitude, and duration of CHABs are increasing globally. Cyanobacterial species traits and changing environmental conditions, including anthropogenic pressure, eutrophication, and global climate change, together allow cyanobacteria to thrive. The cyanotoxins include a diverse range of low molecular weight compounds with varying biochemical properties and modes of action. With the application of modern molecular biology techniques, many important aspects of cyanobacteria are being elucidated, including aspects of their diversity, gene-environment interactions, and genes that express cyanotoxins. The toxicological, environmental, and economic impacts of CHABs strongly advocate the need for continuing, extensive efforts to monitor cyanobacterial growth and to understand the mechanisms regulating species composition and cyanotoxin biosynthesis. In this review, we critically examined the genomic organization of some cyanobacterial species that lead to the production of cyanotoxins and their characteristic properties discovered to date.
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Affiliation(s)
- Fahim Bashir
- Department of Environmental Science, University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India
| | - Arif Bashir
- Department of Clinical Biochemistry and Biotechnology, Government College for Women, Nawa-Kadal, Srinagar, Jammu & Kashmir, India
| | - Noureddine Bouaïcha
- Laboratory Ecology, Systematic, and Evolution, UMR 8079 Univ. Paris-Sud, CNRS, AgroParisTech, University Paris-Saclay, 91190, Gif-sur-Yvette, France.
| | - Liang Chen
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science (SEES), Yunnan University (YNU), 650500, Kunming, China.
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China.
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Faculty of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an, 710048, China.
| | - Geoffrey A Codd
- Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK
| | - Brett Neilan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Wen-Li Xu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China
| | - Laila Ziko
- School of Life and Medical Sciences, University of Hertfordshire Hosted By Global Academic Foundation, Cairo, Egypt
- Biology Department, School of Sciences and Engineering, The American University in Cairo, New Cairo, 11835, Egypt
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Renan Silva Arruda
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Bashir Ahmad Ganai
- Center of Research for Development (CORD), University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India.
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23
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Wang Q, Liu W, Zeb A, Lian Y, Shi R, Li J, Zheng Z. Toxicity effects of polystyrene nanoplastics and arsenite on Microcystis aeruginosa. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162496. [PMID: 36863597 DOI: 10.1016/j.scitotenv.2023.162496] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Despite the increasing research on the fate of nanoplastics (NPs, <100 nm) in freshwater systems, little is known about the joint toxic effects of metal(loid)s and NPs modified with different functional groups on microalgae. Here, we explored the joint toxic effects of two types of polystyrene NPs [one modified with a sulfonic acid group (PSNPs-SO3H), and one without this functional group (PSNPs)] and arsenic (As) on the microalgae Microcystis aeruginosa. The results highlighted that PSNPs-SO3H showed a smaller hydrodynamic diameter and greater potential to adsorb positively charged ions than PSNPs, contributing to the more severe growth inhibition, while both of them produced oxidative stress. Metabolomics further revealed that the fatty acid metabolism of the microalgae was significantly up-regulated under both NPs exposure, while PSNPs-SO3H down-regulated the tricarboxylic acid cycle (TCA cycle) of the microalgae. As uptake by algae was significantly reduced by 82.58 % and 59.65 % in the presence of 100 mg/L PSNPs and PSNPs-SO3H, respectively. The independent action model showed that the joint toxicity of both NPs with As was assessed as antagonistic. In addition, PSNPs and PSNPs-SO3H had dissimilar effects on the composition of the microalgae extracellular polymeric substances (EPS), resulting in different uptake and adsorption of As, thereby affecting the physiology and biochemistry of algae. Overall, our findings propose that the specific properties of NPs should be considered in future environmental risk assessments.
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Affiliation(s)
- Qi Wang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Weitao Liu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Aurang Zeb
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Yuhang Lian
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Ruiying Shi
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Jiantao Li
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Zeqi Zheng
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
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24
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España Amórtegui JC, Pekar H, Retrato MDC, Persson M, Karlson B, Bergquist J, Zuberovic-Muratovic A. LC-MS/MS Analysis of Cyanotoxins in Bivalve Mollusks-Method Development, Validation and First Evidence of Occurrence of Nodularin in Mussels ( Mytilus edulis) and Oysters ( Magallana gigas) from the West Coast of Sweden. Toxins (Basel) 2023; 15:toxins15050329. [PMID: 37235362 DOI: 10.3390/toxins15050329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
In this paper, an LC-MS/MS method for the simultaneous identification and quantification of cyanotoxins with hydrophilic and lipophilic properties in edible bivalves is presented. The method includes 17 cyanotoxins comprising 13 microcystins (MCs), nodularin (NOD), anatoxin-a (ATX-a), homoanatoxin (h-ATX) and cylindrospermopsin (CYN). A benefit to the presented method is the possibility for the MS detection of MC-LR-[Dha7] and MC-LR-[Asp3] as separately identified and MS-resolved MRM signals, two congeners which were earlier detected together. The performance of the method was evaluated by in-house validation using spiked mussel samples in the quantification range of 3.12-200 µg/kg. The method was found to be linear over the full calibration range for all included cyanotoxins except CYN for which a quadratic regression was used. The method showed limitations for MC-LF (R2 = 0.94), MC-LA (R2 ≤ 0.98) and MC-LW (R2 ≤ 0.98). The recoveries for ATX-a, h-ATX, CYN, NOD, MC-LF and MC-LW were lower than desired (<70%), but stable. Despite the given limitations, the validation results showed that the method was specific and robust for the investigated parameters. The results demonstrate the suitability of the method to be applied as a reliable monitoring tool for the presented group of cyanotoxins, as well as highlight the compromises that need to be included if multi-toxin methods are to be used for the analysis of cyanotoxins with a broader range of chemical properties. Furthermore, the method was used to analyze 13 samples of mussels (Mytilus edulis) and oysters (Magallana gigas) collected in the 2020-2022 summers along the coast of Bohuslän (Sweden). A complementary qualitative analysis for the presence of cyanotoxins in phytoplankton samples collected from marine waters around southern Sweden was performed with the method. Nodularin was identified in all samples and quantified in bivalve samples in the range of 7-397 µg/kg. Toxins produced by cyanobacteria are not included in the European Union regulatory monitoring of bivalves; thus, the results presented in this study can be useful in providing the basis for future work including cyanotoxins within the frame of regulatory monitoring to increase seafood safety.
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Affiliation(s)
- Julio César España Amórtegui
- Science Department, Swedish Food Agency, Box 622, SE-751 26 Uppsala, Sweden
- Chemistry Department, Science Faculty, Universidad Nacional de Colombia, Cr. 45 N° 26-85, Bogotá P.O. Box 111321, Colombia
| | - Heidi Pekar
- Science Department, Swedish Food Agency, Box 622, SE-751 26 Uppsala, Sweden
- Stockholm Water and Waste Company, Bryggerivägen 10, SE-106 36 Stockholm, Sweden
| | - Mark Dennis Chico Retrato
- Department of Chemistry, Biomedical Center, Analytical Chemistry and Neurochemistry, Uppsala University, Box 599, SE-751 24 Uppsala, Sweden
| | - Malin Persson
- Science Department, Swedish Food Agency, Box 622, SE-751 26 Uppsala, Sweden
| | - Bengt Karlson
- Research and Development, Oceanography, Swedish Meteorological and Hydrological Institute, Sven Källfelts Gata 15, SE-426 71 Västra Frölunda, Sweden
| | - Jonas Bergquist
- Department of Chemistry, Biomedical Center, Analytical Chemistry and Neurochemistry, Uppsala University, Box 599, SE-751 24 Uppsala, Sweden
| | - Aida Zuberovic-Muratovic
- Science Department, Swedish Food Agency, Box 622, SE-751 26 Uppsala, Sweden
- Department of Chemistry, Biomedical Center, Analytical Chemistry and Neurochemistry, Uppsala University, Box 599, SE-751 24 Uppsala, Sweden
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25
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Cheng C, Steinman AD, Zhang K, Lin Q, Xue Q, Wang X, Xie L. Risk assessment and identification of factors influencing the historical concentrations of microcystin in Lake Taihu, China. J Environ Sci (China) 2023; 127:1-14. [PMID: 36522044 DOI: 10.1016/j.jes.2022.03.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 03/31/2022] [Accepted: 03/31/2022] [Indexed: 06/17/2023]
Abstract
Understanding the history of microcystins (MCs) pollution in large lakes can help inform future lake management. We collected sediment cores from Lake Taihu to: investigate the long-term record of MCs (MC-LR, MC-YR, and MC-RR), explore the main environmental drivers of MCs, and assess their public health and ecological risks. Results showed that MCs content in all cores increased over time. The core from north Taihu had the highest MC concentrations, with an average total MCs (sum of MC-LR, MC-YR, and MC-RR = TMCs) content of (74.31±328.55) ng/g. The core from eastern Taihu showed the lowest average TMCs content of (2.91±3.95) ng/g. PCA showed that sediment MCs at the three sites were positively correlated with sediment chlorophyll-a. MC-LR and MC-YR in northern and western Taihu negatively correlated with both the sediment total organic carbon/sediment total nitrogen ratio (STOC/STN) and water nitrate (NO3--N) concentration, but three MC congeners at eastern Taihu showed positive correlations with water orthophosphate (PO43--P), NO3--N, and STOC/STN. Generalized additive model analysis at each site revealed that NO3--N was the main TMCs driver in northern and western Taihu where phytoplankton dominated, whereas PO43--P was the main TMCs driver in eastern Taihu where macrophytes dominated. At the whole lake scale, total phosphorus (TP) and PO43--P were the most important environmental drivers influencing MCs; TP explained 47.4%, 44.2%, and 47.6% while orthophosphate explained 34.8%, 31.2%, and 34.7% of the deviance on TMCs, MC-LR, and MC-YR, respectively. NO3--N also showed a strong effect on MCs variation, especially on MC-YR. Risk assessment showed that both ecological and public health risk has increased in recent years. We conclude that while control of phosphorus and nitrogen input should be a major focus for future lake management, lake zone-specific management strategies may also be important.
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Affiliation(s)
- Chen Cheng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Alan D Steinman
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI, USA
| | - Kaiye Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Qi Lin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Qingju Xue
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xing Wang
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Drinking Water Source Protection, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Liqiang Xie
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
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26
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Manganelli M, Testai E, Tazart Z, Scardala S, Codd GA. Co-Occurrence of Taste and Odor Compounds and Cyanotoxins in Cyanobacterial Blooms: Emerging Risks to Human Health? Microorganisms 2023; 11:microorganisms11040872. [PMID: 37110295 PMCID: PMC10146173 DOI: 10.3390/microorganisms11040872] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 03/31/2023] Open
Abstract
Cyanobacteria commonly form large blooms in waterbodies; they can produce cyanotoxins, with toxic effects on humans and animals, and volatile compounds, causing bad tastes and odors (T&O) at naturally occurring low concentrations. Notwithstanding the large amount of literature on either cyanotoxins or T&O, no review has focused on them at the same time. The present review critically evaluates the recent literature on cyanotoxins and T&O compounds (geosmin, 2-methylisoborneol, β-ionone and β-cyclocitral) to identify research gaps on harmful exposure of humans and animals to both metabolite classes. T&O and cyanotoxins production can be due to the same or common to different cyanobacterial species/strains, with the additional possibility of T&O production by non-cyanobacterial species. The few environmental studies on the co-occurrence of these two groups of metabolites are not sufficient to understand if and how they can co-vary, or influence each other, perhaps stimulating cyanotoxin production. Therefore, T&Os cannot reliably serve as early warning surrogates for cyanotoxins. The scarce data on T&O toxicity seem to indicate a low health risk (but the inhalation of β-cyclocitral deserves more study). However, no data are available on the effects of combined exposure to mixtures of cyanotoxins and T&O compounds and to combinations of T&O compounds; therefore, whether the co-occurrence of cyanotoxins and T&O compounds is a health issue remains an open question.
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Affiliation(s)
- Maura Manganelli
- Istituto Superiore di Sanità, Department of Environment and Health, viale Regina Elena, 299, 00162 Rome, Italy; (E.T.); (S.S.)
- Correspondence:
| | - Emanuela Testai
- Istituto Superiore di Sanità, Department of Environment and Health, viale Regina Elena, 299, 00162 Rome, Italy; (E.T.); (S.S.)
| | - Zakaria Tazart
- Department of Food Sciences and Nutrition, University of Malta, 2080 Msida, Malta;
| | - Simona Scardala
- Istituto Superiore di Sanità, Department of Environment and Health, viale Regina Elena, 299, 00162 Rome, Italy; (E.T.); (S.S.)
| | - Geoffrey A. Codd
- School of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK;
- School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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27
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Analysis of the Impact of the Presence of Phylum Cyanobacteria in the Microbiome of Patients with Breast Cancer on Their Prognosis. J Clin Med 2022; 11:jcm11247272. [PMID: 36555890 PMCID: PMC9787457 DOI: 10.3390/jcm11247272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/16/2022] [Accepted: 12/03/2022] [Indexed: 12/13/2022] Open
Abstract
Cyanobacterial blooms caused by Cyanobacteria adversely affect the health of the people living in their vicinity. We elucidated the effect of Cyanobacteria in patients with breast cancer. The serum microbiome of the patients with breast cancer was analyzed using NGS. Serologic tests were performed to analyze the association between the factors affecting the liver function of patients with breast cancer and the amount of Cyanobacteria. In addition, the recurrent-free survival of patients with breast cancer according to the abundance of Cyanobacteria was analyzed. The abundance of Cyanobacteria tended to be correlated with the serological results related to liver function. A high abundance of Cyanobacteria seemed to be more related to late-stage breast cancer. A high recurrent-free survival was related to a low abundance of Cyanobacteria. Even though no toxicity study was conducted, this study demonstrates the impact of phylum Cyanobacteria on the prognosis of patients with breast cancer. Thus, the abundance of Cyanobacteria in the microbiome can help predict the prognosis of patients with breast cancer.
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28
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Kramer BJ, Hem R, Gobler CJ. Elevated CO 2 significantly increases N 2 fixation, growth rates, and alters microcystin, anatoxin, and saxitoxin cell quotas in strains of the bloom-forming cyanobacteria, Dolichospermum. HARMFUL ALGAE 2022; 120:102354. [PMID: 36470609 DOI: 10.1016/j.hal.2022.102354] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/02/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
The effect of rising CO2 levels on cyanobacterial harmful algal blooms (CHABs) is an emerging concern, particularly within eutrophic ecosystems. While elevated pCO2 has been associated with enhanced growth rates of some cyanobacteria, few studies have explored the effect of CO2 and nitrogen availability on diazotrophic (N2-fixing) cyanobacteria that produce cyanotoxins. Here, the effects of elevated CO2 and fixed nitrogen (NO3-) availability on the growth rates, toxin production, and N2 fixation of microcystin, saxitoxin, and anatoxin-a - producing strains of the genus Dolichospermum were quantified. Growth rates of all Dolichospermum spp. were significantly increased by CO2 or both CO2 and NO3- with rates being highest in treatments with the highest levels of CO2 and NO3-for all strains. While NO3- suppressed N2 fixation, diazotrophy significantly increased when NO3--enriched Dolichospermum spp. were supplied with higher CO2 compared to cultures grown under lower CO2 levels. This suggests that diazotrophy will play an increasingly important role in N cycling in CO2-enriched, eutrophic lentic systems. NO3- significantly increased quotas of the N-rich cyanotoxins, microcystin and saxitoxin, at ambient and enriched CO2 levels, respectively. In contrast, elevated CO2 significantly decreased cell quotas of microcystin and saxitoxin, but significantly increased cell quotas of the N-poor cyanotoxin, anatoxin. N2 fixation was significantly negatively and positively correlated with quotas of N-rich and N-poor cyanotoxins, respectively. Findings suggest cellular quotas of N-rich toxins (microcystin and saxitoxin) may be significantly reduced, or cellular quotas of N-poor toxins (anatoxin) may be significantly enhanced, under elevated CO2 conditions during diazotrophic cyanobacterial blooms. Finally, in the future, ecosystems that experience combinations of excessive N loading and CO2 enrichment may become more prone to toxic blooms of Dolichospermum.
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Affiliation(s)
- Benjamin J Kramer
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968
| | - Ronojoy Hem
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968.
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29
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Facey JA, Violi JP, King JJ, Sarowar C, Apte SC, Mitrovic SM. The Influence of Micronutrient Trace Metals on Microcystis aeruginosa Growth and Toxin Production. Toxins (Basel) 2022; 14:toxins14110812. [PMID: 36422986 PMCID: PMC9694995 DOI: 10.3390/toxins14110812] [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: 10/11/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Microcystis aeruginosa is a widespread cyanobacteria capable of producing hepatotoxic microcystins. Understanding the environmental factors that influence its growth and toxin production is essential to managing the negative effects on freshwater systems. Some micronutrients are important cofactors in cyanobacterial proteins and can influence cyanobacterial growth when availability is limited. However, micronutrient requirements are often species specific, and can be influenced by substitution between metals or by luxury uptake. In this study, M. aeruginosa was grown in modified growth media that individually excluded some micronutrients (cobalt, copper, iron, manganese, molybdenum) to assess the effect on growth, toxin production, cell morphology and iron accumulation. M. aeruginosa growth was limited when iron, cobalt and manganese were excluded from the growth media, whereas the exclusion of copper and molybdenum had no effect on growth. Intracellular microcystin-LR concentrations were variable and were at times elevated in treatments undergoing growth limitation by cobalt. Intracellular iron was notably higher in treatments grown in cobalt-deplete media compared to other treatments possibly due to inhibition or competition for transporters, or due to irons role in detoxifying reactive oxygen species (ROS).
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Affiliation(s)
- Jordan A. Facey
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2000, Australia
- Correspondence:
| | - Jake P. Violi
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2000, Australia
| | - Josh J. King
- CSIRO Land and Water, Lucas Heights, Sydney, NSW 2234, Australia
| | - Chowdhury Sarowar
- Prince of Wales Clinical School, University of New South Wales, Kensington, NSW 2052, Australia
| | - Simon C. Apte
- CSIRO Land and Water, Lucas Heights, Sydney, NSW 2234, Australia
| | - Simon M. Mitrovic
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2000, Australia
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Savadova-Ratkus K, Mazur-Marzec H, Karosienė J, Sivonen K, Suurnäkki S, Kasperovičienė J, Paškauskas R, Koreivienė J. Cyanobacteria and Their Metabolites in Mono- and Polidominant Shallow Eutrophic Temperate Lakes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15341. [PMID: 36430059 PMCID: PMC9690872 DOI: 10.3390/ijerph192215341] [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: 10/02/2022] [Revised: 11/12/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
Monodominant (one species dominates) or polidominant (multiple species dominate) cyanobacterial blooms are pronounced in productive freshwater ecosystems and pose a potential threat to the biota due to the synthesis of toxins. Seasonal changes in cyanobacteria species and cyanometabolites composition were studied in two shallow temperate eutrophic lakes. Data on cyanobacteria biomass and diversity of dominant species in the lakes were combined with chemical and molecular analyses of fifteen potentially toxin-producing cyanobacteria species (248 isolates from the lakes). Anatoxin-a, saxitoxin, microcystins and other non-ribosomal peptides formed the diverse profiles in monodominant (Planktothrix agardhii) and polidominant (Aphanizomenon gracile, Limnothrix spp. and Planktolyngbya limnetica) lakes. However, the harmfulness of the blooms depended on the ability of the dominant species to synthesize cyanometabolites. It was confirmed that P. agardhii produced a greater amount and diverse range of MCs and other NRPs. In the polidominant lake, isolates of the co-dominant A. gracile, L. planctonica and P. limnetica synthesized no or only small amounts of cyanometabolites. In general, the profile of cyanometabolites was greater in cyanobacteria isolates than in environmental samples, indicating a high potential for toxic cyanobacteria bloom.
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Affiliation(s)
- Ksenija Savadova-Ratkus
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos Str. 2, LT-08412 Vilnius, Lithuania
| | - Hanna Mazur-Marzec
- Division of Marine Biotechnology, Institute of Oceanography, University of Gdańsk, M. J. Piłsudskiego 46, PL-81378 Gdynia, Poland
| | - Jūratė Karosienė
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos Str. 2, LT-08412 Vilnius, Lithuania
| | - Kaarina Sivonen
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Biocenter 1, P.O. Box 56, FIN-00014 Helsinki, Finland
| | - Suvi Suurnäkki
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FIN-40014 Jyväskylä, Finland
| | - Jūratė Kasperovičienė
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos Str. 2, LT-08412 Vilnius, Lithuania
| | - Ričardas Paškauskas
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos Str. 2, LT-08412 Vilnius, Lithuania
| | - Judita Koreivienė
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos Str. 2, LT-08412 Vilnius, Lithuania
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Kim Tiam S, Comte K, Dalle C, Delagrange M, Djediat C, Ducos B, Duval C, Feilke K, Hamlaoui S, Le Manach S, Setif P, Yéprémian C, Marie B, Kirilovsky D, Gugger M, Bernard C. The success of the bloom-forming cyanobacteria Planktothrix: Genotypes variability supports variable responses to light and temperature stress. HARMFUL ALGAE 2022; 117:102285. [PMID: 35944963 DOI: 10.1016/j.hal.2022.102285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/05/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacterial blooms can modify the dynamic of aquatic ecosystems and have harmful consequences for human activities. Moreover, cyanobacteria can produce a variety of cyanotoxins, including microcystins, but little is known about the role of environmental factors on the prevalence of microcystin producers in the cyanobacterial bloom dynamics. This study aimed to better understand the success of Planktothrix in various environments by unveiling the variety of strategies governing cell responses to sudden changes in light intensity and temperature. The cellular responses (photosynthesis, photoprotection, heat shock response and metabolites synthesis) of four Planktothrix strains to high-light or high-temperature were studied, focusing on how distinct ecotypes (red- or green-pigmented) and microcystin production capability affect cyanobacteria's ability to cope with such abiotic stimuli. Our results showed that high-light and high-temperature impact different cellular processes and that Planktothrix responses are heterogeneous, specific to each strain and thus, to genotype. The ability of cyanobacteria to cope with sudden increase in light intensity and temperature was not related to red- or green-pigmented ecotype or microcystin production capability. According to our results, microcystin producers do not cope better to high-light or high-temperature and microcystin content does not increase in response to such stresses.
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Affiliation(s)
- Sandra Kim Tiam
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France.
| | - Katia Comte
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France
| | - Caroline Dalle
- Institut Pasteur, Université Paris Cité, Collection of Cyanobacteria, Paris, F-75015, France
| | - Marine Delagrange
- Laboratoire de Physique Statistique, École Normale Supérieure, PSL Research University, Université Paris Diderot Sorbonne Paris-Cité, Sorbonne Université UPMC Paris 06, CNRS, High Throughput qPCR Core Facility of the ENS, IBENS, 46 rue d'Ulm, Paris,, 75005 France
| | - Chakib Djediat
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France
| | - Bertrand Ducos
- Laboratoire de Physique Statistique, École Normale Supérieure, PSL Research University, Université Paris Diderot Sorbonne Paris-Cité, Sorbonne Université UPMC Paris 06, CNRS, High Throughput qPCR Core Facility of the ENS, IBENS, 46 rue d'Ulm, Paris,, 75005 France
| | - Charlotte Duval
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France
| | - Kathleen Feilke
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, 91198, France
| | - Sahima Hamlaoui
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France
| | - Séverine Le Manach
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France
| | - Pierre Setif
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, 91198, France
| | - Claude Yéprémian
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France
| | - Benjamin Marie
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France
| | - Diana Kirilovsky
- Institute for Integrative Biology of the Cell (I2BC), CNRS, CEA, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, 91198, France
| | - Muriel Gugger
- Institut Pasteur, Université Paris Cité, Collection of Cyanobacteria, Paris, F-75015, France.
| | - Cécile Bernard
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), Muséum National d'Histoire Naturelle, CNRS, CP 39, 57 rue Cuvier, Paris, 75005, France.
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Buley RP, Gladfelter MF, Fernandez-Figueroa EG, Wilson AE. Can correlational analyses help determine the drivers of microcystin occurrence in freshwater ecosystems? A meta-analysis of microcystin and associated water quality parameters. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:493. [PMID: 35690674 DOI: 10.1007/s10661-022-10114-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 05/15/2022] [Indexed: 06/15/2023]
Abstract
Microcystin (MC) is a toxic secondary metabolite produced by select cyanobacteria that threatens aquatic and terrestrial organisms over a diverse range of freshwater systems. To assess the relationship between environmental parameters and MC, researchers frequently utilize correlational analyses. This statistical methodology has proved useful when summarizing complex water quality monitoring datasets, but the correlations between select parameters and MC have been documented to vary widely across studies and systems. Such variation within the peer-reviewed literature leaves uncertainty for resource managers when developing a MC monitoring program. The objective of this research is to determine if correlational analyses between environmental parameters and MC are helpful to resource managers desiring to understand the drivers of MC. Environmental (i.e., physical, chemical, and biological) and MC correlation data were retrieved from an estimated 2,643 waterbodies (largely from the north temperate region) and synthesized using a Fisher's z meta-analysis. Common water quality parameters, such as chlorophyll, temperature, and pH, were positively correlated with MC, while transparency was negatively correlated. Interestingly, 12 of the 15 studied nitrogen parameters, including total nitrogen, were not significantly correlated with MC. In contrast, three of the four studied phosphorus parameters, including total phosphorus, were positively related to MC. Results from this synthesis quantitatively reinforces the usefulness of commonly measured environmental parameters to monitor for conditions related to MC occurrence; however, correlational analyses by themselves are often ineffective and considering what role a parameter plays in the ecology of cyanobacterial blooms in addition to MC production is vital.
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Affiliation(s)
- Riley P Buley
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - Matthew F Gladfelter
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | | | - Alan E Wilson
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
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Microcystin Contamination and Toxicity: Implications for Agriculture and Public Health. Toxins (Basel) 2022; 14:toxins14050350. [PMID: 35622596 PMCID: PMC9145844 DOI: 10.3390/toxins14050350] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/02/2022] [Accepted: 05/12/2022] [Indexed: 01/02/2023] Open
Abstract
Microcystins are natural hepatotoxic metabolites secreted by cyanobacteria in aquatic ecosystems. When present at elevated concentrations, microcystins can affect water quality aesthetics; contaminate drinking water reservoirs and recreational waters; disrupt normal ecosystem functioning; and cause health hazards to animals, plants, and humans. Animal and human exposures to microcystins generally result from ingesting contaminated drinking water or physically contacting tainted water. Much research has identified a multitude of liver problems from oral exposure to microcystins, varying from hepatocellular damage to primary liver cancer. Provisional guidelines for microcystins in drinking and recreational water have been established to prevent toxic exposures and protect public health. With increasing occurrences of eutrophication in freshwater systems, microcystin contamination in groundwater and surface waters is growing, posing threats to aquatic and terrestrial plants and agricultural soils used for crop production. These microcystins are often transferred to crops via irrigation with local sources of water, such as bloom-forming lakes and ponds. Microcystins can survive in high quantities in various parts of plants (roots, stems, and leaves) due to their high chemical stability and low molecular weight, increasing health risks for consumers of agricultural products. Studies have indicated potential health risks associated with contaminated fruits and vegetables sourced from irrigated water containing microcystins. This review considers the exposure risk to humans, plants, and the environment due to the presence of microcystins in local water reservoirs used for drinking and irrigation. Additional studies are needed to understand the specific health impacts associated with the consumption of microcystin-contaminated agricultural plants.
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Latour D, Perrière F, Purdie D. Higher sensitivity to hydrogen peroxide and light stress conditions of the microcystin producer Microcystis aeruginosa sp PCC7806 compared to non-producer strains. HARMFUL ALGAE 2022; 114:102219. [PMID: 35550290 DOI: 10.1016/j.hal.2022.102219] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/14/2022] [Accepted: 02/25/2022] [Indexed: 06/15/2023]
Abstract
The increasing incidence of cyanobacterial blooms with their associated production of cyanotoxins lead managers of aquatics systems to control their biomass to limit the health risk. Among the variety of existing treatment approaches, hydrogen peroxide (H2O2) shows increasing use but the effects of environmental parameters on its effectiveness are still not completely known. With the aim to assess the efficiency of H2O2 treatments in the control of cyanobacterial blooms and decrease toxic risk, we tested three Microcystis strains according to their ability to produce cyanotoxins (a microcystin-producing, non-microcystin-producing and mcyB-knockout mutant). Photochemical efficiency, percentage of living cells and microcystin cell content were compared under various hydrogen peroxide concentrations coupled with stress conditions encountered during the life cycle of cyanobacteria as darkness and high light. The microcystin-producing strain appeared the more sensitive to hydrogen peroxide treatment and to light condition, probably due to a lower rate of repair of Photo System II (PSII). We also highlighted various responses of PSII activity according to Microcystis strains which could partly explain the shift of dominant genotypes often occurring during a bloom event. Our results confirm the link between light and microcystin content and variations of microcystin contents appear as a consequence of photosynthetic activity. These findings could be of particular interest regarding water quality management, especially the use of H2O2 as a potential algaecide which seems to be more effective to use during periods of high light.
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Affiliation(s)
- Delphine Latour
- Université Clermont Auvergne, CNRS, LMGE-UMR 6023, F-63178 Aubière Cedex, France.
| | - Fanny Perrière
- Université Clermont Auvergne, CNRS, LMGE-UMR 6023, F-63178 Aubière Cedex, France
| | - Duncan Purdie
- University of Southampton, National Oceanography Centre, Waterfront Campus, European Way, Southampton SO14 3ZH, United Kingdom
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Mohanty B, Majedi SM, Pavagadhi S, Te SH, Boo CY, Gin KYH, Swarup S. Effects of Light and Temperature on the Metabolic Profiling of Two Habitat-Dependent Bloom-Forming Cyanobacteria. Metabolites 2022; 12:406. [PMID: 35629910 PMCID: PMC9146292 DOI: 10.3390/metabo12050406] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/23/2022] [Accepted: 04/26/2022] [Indexed: 01/27/2023] Open
Abstract
Rapid proliferation of cyanobacteria in both benthic and suspended (planktonic) habitats is a major threat to environmental safety, as they produce nuisance compounds such as cytotoxins and off-flavors, which degrade the safety and quality of water supplies. Temperature and light irradiance are two of the key factors in regulating the occurrence of algal blooms and production of major off-flavors. However, the role of these factors in regulating the growth and metabolism is poorly explored for both benthic and planktonic cyanobacteria. To fill this gap, we studied the effects of light and temperature on the growth and metabolic profiling of both benthic (Hapalosiphon sp. MRB220) and planktonic (Planktothricoides sp. SR001) environmental species collected from a freshwater reservoir in Singapore. Moreover, this study is the first report on the metabolic profiling of cyanobacteria belonging to two different habitats in response to altered environmental conditions. The highest growth rate of both species was observed at the highest light intensity (100 μmol photons/m²/s) and at a temperature of 33 °C. Systematic metabolite profiling analysis suggested that temperature had a more profound effect on metabolome of the Hapalosiphon, whereas light had a greater effect in the case of Planktothricoides. Interestingly, Planktothricoides sp. SR001 showed a specialized adaptation mechanism via biosynthesis of arginine, and metabolism of cysteine and methionine to survive and withstand higher temperatures of 38 °C and higher. Hence, the mode of strategies for coping with different light and temperature conditions was correlated with the growth and alteration in metabolic activities for physiological and ecological adaptations in both species. In addition, we putatively identified a number of unique metabolites with a broad range of antimicrobial activities in both species in response to both light and temperature. These metabolites could play a role in the dominant behavior of these species in suppressing competition during bloom formation. Overall, this study elucidated novel insights into the effects of environmental factors on the growth, metabolism, and adaptation strategies of cyanobacteria from two different habitats, and could be useful in controlling their harmful effects on human health and environmental concerns.
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Affiliation(s)
- Bijayalaxmi Mohanty
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; (B.M.); (S.M.M.); (S.P.); (S.H.T.); (C.Y.B.); (K.Y.-H.G.)
| | - Seyed Mohammad Majedi
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; (B.M.); (S.M.M.); (S.P.); (S.H.T.); (C.Y.B.); (K.Y.-H.G.)
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore 117456, Singapore
| | - Shruti Pavagadhi
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; (B.M.); (S.M.M.); (S.P.); (S.H.T.); (C.Y.B.); (K.Y.-H.G.)
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore 117456, Singapore
| | - Shu Harn Te
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; (B.M.); (S.M.M.); (S.P.); (S.H.T.); (C.Y.B.); (K.Y.-H.G.)
| | - Chek Yin Boo
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; (B.M.); (S.M.M.); (S.P.); (S.H.T.); (C.Y.B.); (K.Y.-H.G.)
| | - Karina Yew-Hoong Gin
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; (B.M.); (S.M.M.); (S.P.); (S.H.T.); (C.Y.B.); (K.Y.-H.G.)
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Sanjay Swarup
- NUS Environmental Research Institute, National University of Singapore, Singapore 117411, Singapore; (B.M.); (S.M.M.); (S.P.); (S.H.T.); (C.Y.B.); (K.Y.-H.G.)
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore 117456, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
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Tito JCR, Luna LMG, Noppe WN, Hubert IA. First Report on Microcystin-LR Occurrence in Water Reservoirs of Eastern Cuba, and Environmental Trigger Factors. Toxins (Basel) 2022; 14:209. [PMID: 35324706 PMCID: PMC8952431 DOI: 10.3390/toxins14030209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 01/20/2023] Open
Abstract
The factors related to cyanotoxin occurrence and its social impact, with comprehension and risk perception being the most important issues, are not yet completely understood in the Cuban context. The objectives of this research were to determine the risk extension and microcystin-LR levels, and to identify the environmental factors that trigger the toxic cyanobacteria growth and microcystin-LR occurrence in 24 water reservoirs in eastern Cuba. Samplings were performed in the early morning hours, with in situ determination and physicochemical analysis carried out in the laboratory. Microcystin-LR were determined in water and within the cells (intracellular toxins) using UPLC-MS analysis after solid phase extraction. The reservoirs studied were found to be affected by eutrophication, with high levels of TN:TP ratio and phytoplankton cell concentrations, high water temperatures and low transparency, which cause collateral effect such as cyanobacterial bloom and microcystin-LR occurrence. In Hatillo, Chalóns, Parada, Mícara, Baraguá, Cautillo, La Yaya, Guisa and Jaibo reservoirs, concentrations of MC-LR higher than the WHO limits for drinking water (1 µg·L-1), were detected.
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Affiliation(s)
| | - Liliana Maria Gomez Luna
- Faculty of Chemical Engineering and Agronomy, University of Oriente, Santiago de Cuba 90400, Cuba;
- National Centre of Applied Electromagnetism, University of Oriente, Santiago de Cuba 90400, Cuba
| | - Wim Noppe Noppe
- Department of Biology, Aquatic Biology, KU Leuven Kulak, E. Sabbelaan 53, 8500 Kortrijk, Belgium;
| | - Inaudis Alvarez Hubert
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química, Universidad Técnica Federico Santamaria, Valparaiso 2390123, Chile;
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Kesari V, Kumar S, Yadav I, Chatterjee A, Rai S, Pandey S. Ganga river water quality assessment using combined approaches: physico-chemical parameters and cyanobacterial toxicity detection with special reference to microcystins and molecular characterization of microcystin synthetase (mcy) genes carrying cyanobacteria. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:13122-13140. [PMID: 34570320 DOI: 10.1007/s11356-021-16589-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Water quality assessment relies mostly on physico-chemical-based characterization; however, eutrophication and climate change advocate the abundance of toxic microcystins (MCs) producing cyanobacteria as emerging bio-indicator. In the present study, a spatial-temporal analysis was carried out at ten sampling sites of Prayagraj and Varanasi during June 2017 and March 2018 to determine the Ganga River water quality using physico-chemical parameters, cyanobacteria diversity, detection of MCs producing strains and MC-LR equivalence. Coliform bacteria, COD, NO3-N, and phosphate are the significant contaminated parameters favoring the growth of putative MCs producing cyanobacteria. National Sanitation Foundation WQI (NSFWQI) indicates water quality, either bad or medium category at sampling points. The morphological analysis confirms the occurrence of diverse cyanobacterial genera such as Microcystis, Anabaena, Oscillatoria, and Phormidium. PCR amplification affirmed the presence of toxic microcystin (mcy) genes in uncultured cyanobacteria at all the sampling sites. The concentration of MC-LR equivalence in water samples by protein phosphatase 1 inhibition assay (PPIA) and high-performance liquid chromatography (HPLC) methods was observed in the range of 23.4-172 ng/L and 13.2-97.5 ng/L respectively which is lower than the harmful exposure limit by World Health Organization (WHO). Ganga isolate 1 was identified as Microcystis based on partial 16S rDNA sequence and its toxicity was confirmed due to presence of mcy genes and MCs production potential. These findings suggest the presence of MCs producers as new emerging parameter to monitor water quality index and identification up to species level will be valuable for restoration strategies of river Ganga.
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Affiliation(s)
- Vigya Kesari
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
| | - Sanjay Kumar
- School of Biochemical Engineering, Indian Institute of Technology (BHU) Varanasi, Varanasi, U.P, India
| | - Indrajeet Yadav
- School of Biochemical Engineering, Indian Institute of Technology (BHU) Varanasi, Varanasi, U.P, India
| | - Antra Chatterjee
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Shweta Rai
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
- Department of Botany, Braj Mohan Das College (B.R. Ambedkar Bihar University), Vaishali, Bihar, India
| | - Shraddha Pandey
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
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Li H, Gu X, Chen H, Mao Z, Shen R, Zeng Q, Ge Y. Co-occurrence of multiple cyanotoxins and taste-and-odor compounds in the large eutrophic Lake Taihu, China: Dynamics, driving factors, and challenges for risk assessment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 294:118594. [PMID: 34848287 DOI: 10.1016/j.envpol.2021.118594] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 10/31/2021] [Accepted: 11/25/2021] [Indexed: 06/13/2023]
Abstract
Cyanobacterial blooms producing toxic metabolites occur frequently in freshwater, yet the environmental behaviors of complex cyanobacterial metabolites remain largely unknown. In this study, the seasonal and spatial variations of several classes of cyanotoxins (microcystins, cylindrospermopsins, saxitoxins) and taste-and-odor (T&O) compounds (β-cyclocitral, β-ionone, geosmin, 2-methylisoborneol) in Lake Taihu were simultaneously investigated for the first time. The total cyanotoxins were dominated by microcystins with concentrations highest in November (mean 2209 ng/L) and lowest in February (mean 48.7 ng/L). Cylindrospermopsins were abundant in May with the highest content of 622.8 ng/L. Saxitoxins only occurred in May (mean 19.2 ng/L) and November (mean 198.5 ng/L). Extracellular T&O compounds were most concentrated in August, the highest being extracellular β-cyclocitral (mean 240.6 ng/L) followed by 2-methylisoborneol (mean 146.6 ng/L). Environment variables play conflicting roles in modulating the dynamics of different groups of cyanotoxins and T&O compounds. Total phosphorus (TP), total nitrogen (TN), chlorophyll-a and cyanobacteria density were important factors affecting the variation of total microcystins, β-cyclocitral and β-ionone concentrations. In contrast, total cylindrospermopsins, 2-methylisoborneol and geosmin concentrations were significantly influenced by water temperature and TP. There was a significant and linear relationship between microcystins and β-cyclocitral/β-ionone, while cylindrospermopsins were positively correlated with 2-methylisoborneol and geosmin. The perceptible odors may be good indicators for the existence of cyanotoxins. Hazard quotients revealed that potential human health risks from microcystins were high in August and November. Meanwhile, the risks from cylindrospermopsins were at moderate levels. Cylindrospermopsins and saxitoxins were first identified in this lake, suggesting that diverse cyanotoxins might co-occur more commonly than previously thought. Hence, the risks from other cyanotoxins beyond microcystins shouldn't be ignored. This study also highlights that the necessity for further assessing the combination effects of these complex metabolites.
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Affiliation(s)
- Hongmin Li
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaohong Gu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Huihui Chen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Zhigang Mao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Ruijie Shen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qingfei Zeng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - You Ge
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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Wang H, Kim H, Park H, Ki JS. Temperature influences the content and biosynthesis gene expression of saxitoxins (STXs) in the toxigenic dinoflagellate Alexandrium pacificum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 802:149801. [PMID: 34454155 DOI: 10.1016/j.scitotenv.2021.149801] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Temperature may affect the production of saxitoxin (STX) and its derivatives (STXs); however, this is still controversial. Further, STX-biosynthesis gene regulation and the relation of its toxicity with temperature are not clearly understood. In the present study, we evaluated the effects of different temperatures (12 °C, 16 °C, and 20 °C) on the growth, toxin profiles, and expression of two core STX-biosynthesis genes, sxtA and sxtG, in the toxic dinoflagellate Alexandrium pacificum Alex05, isolated from Korean coasts. We found that temperature significantly affected cell growth, with maximum growth recorded at 16 °C, followed by 20 °C and 12 °C. HPLC analysis revealed mostly 12 of STXs from the tested cultures. Interestingly, the contents of STXs increased in the cells cultured at 16 °C and exposed to cold stress, compared to the 20 °C culture and heat stress; however, toxin components were much more diverse under heat stress. These toxin profiles generally matched with the sxtA and sxtG expression levels. Incubation at lower temperatures (12 °C and 16 °C) and exposure to cold stress increased sxtA and sxtG expressions in the cells, whereas heat stress showed little change or downregulated the transcription of both genes. Principal component analysis (PCA) showed low correlation between STXs eq and expressional levels of sxtA and sxtG in heat-stressed cells. These results suggest that temperature might be a crucial factor affecting the level and biosynthesis of STXs in marine toxic dinoflagellates.
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Affiliation(s)
- Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea; Hunan Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hyunjun Park
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
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Lei L, Lei M, Cheng N, Chen Z, Xiao L, Han BP, Lin Q. Nutrient Regulation of Relative Dominance of Cylindrospermopsin-Producing and Non-cylindrospermopsin-Producing Raphidiopsis raciborskii. Front Microbiol 2021; 12:793544. [PMID: 34899674 PMCID: PMC8664406 DOI: 10.3389/fmicb.2021.793544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
Raphidiopsis raciborskii (previously Cylindrospermopsis raciborskii) can produce cylindrospermopsin (CYN) which is of great concern due to its considerable toxicity to human and animals. Its CYN-producing (toxic) and non-CYN-producing (non-toxic) strains co-exist commonly in natural water bodies, while how their relative dominance is regulated has not been addressed. In this study, we combined field investigation with laboratory experiments to assessed the relationship between toxic and non-toxic R. raciborskii abundances under different nutrient levels. The rpoC1- and cyrJ-based qPCR was applied for quantifying total and toxic R. raciborskii abundances, respectively. The field survey showed that toxic R. raciborskii was detected in 97 of 115 reservoirs where its proportion ranged from 0.3% to 39.7% within the R. raciborskii population. Both total and toxic R. raciborskii abundances increased significantly with trophic level of these reservoirs, consistent with our monoculture and co-culture experiments showing in an increase in R. raciborskii growth with increasing nitrogen (N) or phosphorus (P) concentrations. In the monoculture experiments, growth rates of non-toxic and toxic strains from Australia or China were not significantly different under the same culture conditions. On the other hand, in the co-culture experiments, the toxic strains displayed a significantly faster growth than non-toxic strains under nutrient-replete conditions, resulting in an obvious shift toward the dominance by toxic strains from day 3 to the end of the experiments, regardless of the strain originating from Australia or China. The reverse was found under N- or P-limited conditions. Our results indicated that the toxic strains of R. raciborskii have a competitive advantage relative to the non-toxic strains in a more eutrophic world. In parallel to an increase in dominance, both toxic strains grown in the mixed population significantly increased CYN production under nutrient-replete conditions as compared to nutrient-limited conditions, suggesting that CYN may be of significance for ecological advantage of toxic R. raciborskii. These results highlight the importance of nutrient availability in regulating abundances and strain dominance of two genotypes of R. raciborskii. Our findings demonstrated that elevated nutrients would favor the growth of CYN-producing R. raciborskii and CYN production, leading to more blooms with higher toxicity at global scale.
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Affiliation(s)
- Lamei Lei
- Department of Ecology, Jinan University, Guangzhou, China
| | - Minting Lei
- Department of Ecology, Jinan University, Guangzhou, China
| | - Nan Cheng
- Department of Ecology, Jinan University, Guangzhou, China
| | - Zhijiang Chen
- Department of Ecology, Jinan University, Guangzhou, China
| | - Lijuan Xiao
- Department of Ecology, Jinan University, Guangzhou, China
| | - Bo-Ping Han
- Department of Ecology, Jinan University, Guangzhou, China
| | - Qiuqi Lin
- Department of Ecology, Jinan University, Guangzhou, China
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Overlingė D, Toruńska-Sitarz A, Kataržytė M, Pilkaitytė R, Gyraitė G, Mazur-Marzec H. Characterization and Diversity of Microcystins Produced by Cyanobacteria from the Curonian Lagoon (SE Baltic Sea). Toxins (Basel) 2021; 13:toxins13120838. [PMID: 34941676 PMCID: PMC8703916 DOI: 10.3390/toxins13120838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 12/30/2022] Open
Abstract
Microcystins (MCs) are the most widely distributed and structurally diverse cyanotoxins that can have significant health impacts on living organisms, including humans. The identification of MC variants and their quantification is very important for toxicological assessment. Within this study, we explored the diversity of MCs and their potential producers from the Curonian Lagoon. MC profiles were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, while the potential producers were detected based on the presence of genus-specific mcyE gene sequences. Among the numerous MCs detected, one new potential MC variant with m/z 1057 was partially characterized. Moreover, two other MCs with m/z 1075 and m/z 1068 might belong to new variants with serine (Ser), rarely detected in position one of the peptides. They might also represent MC-Y(OMe)R and MC-WR, respectively. However, the application of a low-resolution MS/MS system made the unambiguous identification of the MCs impossible. Based on this example, the problems of peptide structure identification are discussed in the work. Genetic analysis revealed that potential MCs producers include Dolichospermum/Anabaena, Microcystis spp., and Planktothrix agardhii. The diversity and temporal variations in MC profiles may indicate the presence of several chemotypes of cyanobacteria in the Curonian Lagoon.
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Affiliation(s)
- Donata Overlingė
- Marine Research Institute, Klaipeda University, University Avenue 17, 92295 Klaipeda, Lithuania; (M.K.); (R.P.); (G.G.)
- Correspondence:
| | - Anna Toruńska-Sitarz
- Division of Marine Biotechnology, Faculty of Oceanography and Geography, University of Gdańsk, Marszałka J. Piłsudskiego 46, PL-81378 Gdynia, Poland; (A.T.-S.); (H.M.-M.)
| | - Marija Kataržytė
- Marine Research Institute, Klaipeda University, University Avenue 17, 92295 Klaipeda, Lithuania; (M.K.); (R.P.); (G.G.)
| | - Renata Pilkaitytė
- Marine Research Institute, Klaipeda University, University Avenue 17, 92295 Klaipeda, Lithuania; (M.K.); (R.P.); (G.G.)
| | - Greta Gyraitė
- Marine Research Institute, Klaipeda University, University Avenue 17, 92295 Klaipeda, Lithuania; (M.K.); (R.P.); (G.G.)
| | - Hanna Mazur-Marzec
- Division of Marine Biotechnology, Faculty of Oceanography and Geography, University of Gdańsk, Marszałka J. Piłsudskiego 46, PL-81378 Gdynia, Poland; (A.T.-S.); (H.M.-M.)
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Abdallah MF, Van Hassel WHR, Andjelkovic M, Wilmotte A, Rajkovic A. Cyanotoxins and Food Contamination in Developing Countries: Review of Their Types, Toxicity, Analysis, Occurrence and Mitigation Strategies. Toxins (Basel) 2021; 13:786. [PMID: 34822570 PMCID: PMC8619289 DOI: 10.3390/toxins13110786] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 12/27/2022] Open
Abstract
Cyanotoxins have gained global public interest due to their potential to bioaccumulate in food, which threatens human health. Bloom formation is usually enhanced under Mediterranean, subtropical and tropical climates which are the dominant climate types in developing countries. In this context, we present an up-to-date overview of cyanotoxins (types, toxic effects, analysis, occurrence, and mitigation) with a special focus on their contamination in (sea)food from all the developing countries in Africa, Asia, and Latin America as this has received less attention. A total of 65 publications have been found (from 2000 until October 2021) reporting the contamination by one or more cyanotoxins in seafood and edible plants (five papers). Only Brazil and China conducted more research on cyanotoxin contamination in food in comparison to other countries. The majority of research focused on the detection of microcystins using different analytical methods. The detected levels mostly surpassed the provisional tolerable daily intake limit set by the World Health Organization, indicating a real risk to the exposed population. Assessment of cyanotoxin contamination in foods from developing countries still requires further investigations by conducting more survey studies, especially the simultaneous detection of multiple categories of cyanotoxins in food.
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Affiliation(s)
- Mohamed F. Abdallah
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium;
| | - Wannes H. R. Van Hassel
- Sciensano, Chemical and Physical Health Risks, Organic Contaminants and Additives, Leuvensesteenweg 17, 3080 Tervuren, Belgium;
| | - Mirjana Andjelkovic
- Sciensano Research Institute, Chemical and Physical Health Risks, Risk and Health Impact Assessment, Ju-liette Wytsmanstreet 14, 1050 Brussels, Belgium;
| | - Annick Wilmotte
- BCCM/ULC Cyanobacteria Collection, InBios-Centre for Protein Engineering, Université de Liège, 4000 Liège, Belgium;
| | - Andreja Rajkovic
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium;
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Ahmad IZ. The usage of Cyanobacteria in wastewater treatment: prospects and limitations. Lett Appl Microbiol 2021; 75:718-730. [PMID: 34687552 DOI: 10.1111/lam.13587] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/27/2021] [Accepted: 10/14/2021] [Indexed: 11/26/2022]
Abstract
The applicability of Cyanobacteria executes various roles in the treatment of wastewater, assembling of superfluous food and, thus, produces valued biomass which has various applications. Besides this, they enrich and improve the quality of water as they are photosynthetic autotrophs. Currently, Cyanobacteria gained momentum for remediation of wastewaters because firstly, they enhances the O2 content of waters through photosynthesis and perform bioremediation of some heavy metals. Secondly, Cyanobacteria play significant roles in distressing the biological oxygen demand, chemical oxygen demand, turbidity, minerals and microbes; thirdly, they can be used either as axenic cultures or as mixed cultures both offering distinct advantages. Lastly, some species are tolerant towards extreme temperatures both low and high, acidic pH, high salt concentrations and heavy metals, which makes them outstanding candidates for the wastewater treatment plants. The suitable immobilization methods must evolve, better understanding of their morphological and biochemical parameters is required for the optimum growth, easy methods of harvesting the biomass after the treatment are required and more trials on large-scale basis are required before they can be launched on full-fledged basis for wastewater treatments.
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Affiliation(s)
- Iffat Zareen Ahmad
- Department of Bioengineering, Integral University, Lucknow, Uttar Pradesh, India
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Tazart Z, Manganelli M, Scardala S, Buratti FM, Nigro Di Gregorio F, Douma M, Mouhri K, Testai E, Loudiki M. Remediation Strategies to Control Toxic Cyanobacterial Blooms: Effects of Macrophyte Aqueous Extracts on Microcystis aeruginosa (Growth, Toxin Production and Oxidative Stress Response) and on Bacterial Ectoenzymatic Activities. Microorganisms 2021; 9:microorganisms9081782. [PMID: 34442861 PMCID: PMC8400474 DOI: 10.3390/microorganisms9081782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
Increasing toxic cyanobacterial blooms in freshwater demand environmentally friendly solutions to control their growth and toxicity, especially in arid countries, where most drinking water is produced from surface reservoirs. We tested the effects of macrophyte allelochemicals on Microcystis aeruginosa and on the fundamental role of bacteria in nutrient recycling. The effects of Ranunculus aquatilis aqueous extract, the most bioactive of four Moroccan macrophyte extracts, were tested in batch systems on M. aeruginosa growth, toxin production and oxidative stress response and on the ectoenzymatic activity associated with the bacterial community. M. aeruginosa density was reduced by 82.18%, and a significant increase in oxidative stress markers was evidenced in cyanobacterial cells. Microcystin concentration significantly decreased, and they were detected only intracellularly, an important aspect in managing toxic blooms. R. aquatilis extract had no negative effects on associated bacteria. These results confirm a promising use of macrophyte extracts, but they cannot be generalized. The use of the extract on other toxic strains, such as Planktothrix rubescens, Raphidiopsis raciborskii and Chrysosporum ovalisporum, caused a reduction in growth rate but not in cyanotoxin content, increasing toxicity. The need to assess species-specific cyanobacteria responses to verify the efficacy and safety of the extracts for human health and the environment is highlighted.
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Affiliation(s)
- Zakaria Tazart
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
- Water, Biodiversity and Climate Change Laboratory, Phycology, Biotechnology and Environmental Toxicology Research Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah P.O. Box 2390, Marrakech 40000, Morocco; (K.M.); (M.L.)
| | - Maura Manganelli
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
- Correspondence:
| | - Simona Scardala
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Franca Maria Buratti
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Federica Nigro Di Gregorio
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Mountasser Douma
- Environmental Microbiology and Toxicology Research Unit, Polydisciplinary Faculty of Khouribga (FPK), Sultan Moulay Slimane University, Beni Mellal 23000, Morocco;
| | - Khadija Mouhri
- Water, Biodiversity and Climate Change Laboratory, Phycology, Biotechnology and Environmental Toxicology Research Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah P.O. Box 2390, Marrakech 40000, Morocco; (K.M.); (M.L.)
| | - Emanuela Testai
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Mohammed Loudiki
- Water, Biodiversity and Climate Change Laboratory, Phycology, Biotechnology and Environmental Toxicology Research Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah P.O. Box 2390, Marrakech 40000, Morocco; (K.M.); (M.L.)
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Gummaa NR, Dwaish AS, Hamzah IH. Molecular detection of some toxogenic cyanobacteria in Tigris River in Baghdad-Iraq. Mol Biol Rep 2021; 48:5393-5397. [PMID: 34283333 DOI: 10.1007/s11033-021-06538-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/30/2021] [Indexed: 11/29/2022]
Abstract
Cyanobacteria and their pollution are being increasingly commonly reported worldwide that cause a serious hazard to environmental and human health. Cyanotoxin was the most algal toxin reported to be produced by several orders of cyanobacteria. This study aimed to provide a technique to detect cylindrosprmopsin and saxitoxin biosynthesis genes in the river. In November, December 2019, and January 2020. Cyanobacteria were isolated from freshwater of Tigris River and identified by compound microscope also conventional PCR. Five isolates of cyanobacteria that successfully amplified a gene fragment from the phycocyanin were found in all cyanobacteria (Microcystis flosaquae, Microcystis sp, anabaena circinalis, nostoc commune and westiellopsis prolifica) and all isolates successfully amplified aoaC gene to detecting the cylidrospemopsin and the saxitoxin. Our results concluded that PCR assay can be used for early detection of cylidrospemopsin and the saxitoxin producing cyanobacteria in river water that useful to stations responsible for the preparation of drinking water to public.
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Affiliation(s)
- Noor Redha Gummaa
- Biology Department, College of Science, Mustansiriyah University, Baghdad, Iraq
| | - Ahmed Sahi Dwaish
- Biology Department, College of Science, Mustansiriyah University, Baghdad, Iraq
| | - Israa Hussein Hamzah
- Biology Department, College of Science, Mustansiriyah University, Baghdad, Iraq.
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Melaram R. Environmental Risk Factors Implicated in Liver Disease: A Mini-Review. Front Public Health 2021; 9:683719. [PMID: 34249849 PMCID: PMC8264448 DOI: 10.3389/fpubh.2021.683719] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/17/2021] [Indexed: 01/08/2023] Open
Abstract
Liver disease is a global health issue, resulting in about two million deaths per year. It encompasses a wide spectrum of varied or unknown etiologies, ranging from lifestyle choices to pre-existing comorbidities. In recent decades, exposure to environmental toxins and subsequent liver health outcomes have captured public interest, due to the extensive application of pesticides, consumption of aflatoxin contaminated foodstuff, and cyanobacterial harmful algae blooms in endemic regions of liver disease. Hepatocellular carcinoma is a serious and debilitating condition of the liver, characterized by abdominal pain and unexplained weight loss. Established risk factors for hepatocellular carcinoma include alcohol consumption, cigarette smoking, and viral infections of hepatitis B and C. However, mounting evidence suggests that environmental toxins may represent an important contributing factor in hepatocellular carcinoma development. This mini-review synthesizes epidemiological investigations, providing evidence for environmental toxins as one potential risk factor for liver disease.
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Affiliation(s)
- Rajesh Melaram
- School of Health Sciences, Walden University, Minneapolis, MN, United States
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47
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Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806. Microorganisms 2021; 9:microorganisms9061265. [PMID: 34200971 PMCID: PMC8230624 DOI: 10.3390/microorganisms9061265] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 12/02/2022] Open
Abstract
The ubiquitous freshwater cyanobacterium Microcystis is remarkably successful, showing a high tolerance against fluctuations in environmental conditions. It frequently forms dense blooms which can accumulate significant amounts of the hepatotoxin microcystin, which plays an extracellular role as an infochemical but also acts intracellularly by interacting with proteins of the carbon metabolism, notably with the CO2 fixing enzyme RubisCO. Here we demonstrate a direct link between external microcystin and its intracellular targets. Monitoring liquid cultures of Microcystis in a diel experiment revealed fluctuations in the extracellular microcystin content that correlate with an increase in the binding of microcystin to intracellular proteins. Concomitantly, reversible relocation of RubisCO from the cytoplasm to the cell’s periphery was observed. These variations in RubisCO localization were especially pronounced with cultures grown at higher cell densities. We replicated these effects by adding microcystin externally to cultures grown under continuous light. Thus, we propose that microcystin may be part of a fast response to conditions of high light and low carbon that contribute to the metabolic flexibility and the success of Microcystis in the field.
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48
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Wei N, Song L, Gan N. Quantitative Proteomic and Microcystin Production Response of Microcystis aeruginosa to Phosphorus Depletion. Microorganisms 2021; 9:microorganisms9061183. [PMID: 34072711 PMCID: PMC8227402 DOI: 10.3390/microorganisms9061183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 12/20/2022] Open
Abstract
Microcystis blooms are the most widely distributed and frequently occurring cyanobacterial blooms in freshwater. Reducing phosphorus is suggested to be effective in mitigating cyanobacterial blooms, while the underlying molecular mechanisms are yet to be elucidated. In the present study, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics was employed to study the effects of phosphorus depletion on Microcystis aeruginosa FACHB-905. The production of microcystins (MCs), a severe hazard of Microcystis blooms, was also analyzed. In total, 230 proteins were found to be differentially abundant, with 136 downregulated proteins. The results revealed that, upon phosphorus limitation stress, Microcystis aeruginosa FACHB-905 raised the availability of phosphorus primarily by upregulating the expression of orthophosphate transport system proteins, with no alkaline phosphatase producing ability. Phosphorus depletion remarkably inhibited cell growth and the primary metabolic processes of Microcystis, including transcription, translation and photosynthesis, with structures of photosystems remaining intact. Moreover, expression of nitrogen assimilation proteins was downregulated, while proteins involved in carbon catabolism were significantly upregulated, which was considered beneficial for the intracellular balance among carbon, nitrogen and phosphorus. The expression of MC synthetase was not significantly different upon phosphorus depletion, while MC content was significantly suppressed. It is assumed that phosphorus depletion indirectly regulates the production of MC by the inhibition of metabolic processes and energy production. These results contribute to further understanding of the influence mechanisms of phosphorus depletion on both biological processes and MC production in Microcystis cells.
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Affiliation(s)
- Nian Wei
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430072, China
| | - Lirong Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
- Correspondence: (L.S.); (N.G.)
| | - Nanqin Gan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
- Correspondence: (L.S.); (N.G.)
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49
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Depth profiles of protein-bound microcystin in Küçükçekmece Lagoon. Toxicon 2021; 198:156-163. [PMID: 33992691 DOI: 10.1016/j.toxicon.2021.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/17/2021] [Accepted: 05/10/2021] [Indexed: 11/20/2022]
Abstract
Microcystis is the most commonly found toxic cyanobacterial genus around the world and has a negative impact on the ecosystem. As a predominant producer of the potent hepatotoxin microcystin (MC), the genus causes outbreaks in freshwaters worldwide. Standard analytical methods that are used for the detection of microcystin variants can only measure the free form of microcystin in cells. Since microcystin was found as free and protein-bound forms in the cells, a significant proportion of microcystin is underestimated with analytical methods. The aim of the study was to measure protein-bound microcystins and determine the environmental factors that affect the binding of microcystin to proteins. Samples were taken at depths of surface, 1 m, 5 m, 10 m, 15 m, and 18 m in Küçükçekmece Lagoon to analyze depth profiles of two different microcystin forms from June to September 2012 at regular monthly intervals. Our findings suggest that the most important parameter affecting protein-bound microcystin at surface water is high light. Due to favorable environmental conditions such as temperature, light, and physicochemical parameters, the higher microcystin contents, both free and protein-bound MCs, were found in summer periods.
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50
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Algal Toxic Compounds and Their Aeroterrestrial, Airborne and other Extremophilic Producers with Attention to Soil and Plant Contamination: A Review. Toxins (Basel) 2021; 13:toxins13050322. [PMID: 33946968 PMCID: PMC8145420 DOI: 10.3390/toxins13050322] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 12/16/2022] Open
Abstract
The review summarizes the available knowledge on toxins and their producers from rather disparate algal assemblages of aeroterrestrial, airborne and other versatile extreme environments (hot springs, deserts, ice, snow, caves, etc.) and on phycotoxins as contaminants of emergent concern in soil and plants. There is a growing body of evidence that algal toxins and their producers occur in all general types of extreme habitats, and cyanobacteria/cyanoprokaryotes dominate in most of them. Altogether, 55 toxigenic algal genera (47 cyanoprokaryotes) were enlisted, and our analysis showed that besides the “standard” toxins, routinely known from different waterbodies (microcystins, nodularins, anatoxins, saxitoxins, cylindrospermopsins, BMAA, etc.), they can produce some specific toxic compounds. Whether the toxic biomolecules are related with the harsh conditions on which algae have to thrive and what is their functional role may be answered by future studies. Therefore, we outline the gaps in knowledge and provide ideas for further research, considering, from one side, the health risk from phycotoxins on the background of the global warming and eutrophication and, from the other side, the current surge of interest which phycotoxins provoke due to their potential as novel compounds in medicine, pharmacy, cosmetics, bioremediation, agriculture and all aspects of biotechnological implications in human life.
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