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Li H, Yuan Y, Yang H, Xu X, Wang W, Chen Y, Kan C, Zhufu H, Gong C. Consumption of toxic benthic cyanobacteria by two common demersal fish: Growth, antioxidant and liver histopathology responses. Toxicon 2024; 242:107703. [PMID: 38522586 DOI: 10.1016/j.toxicon.2024.107703] [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: 01/03/2024] [Revised: 03/07/2024] [Accepted: 03/22/2024] [Indexed: 03/26/2024]
Abstract
Benthic freshwater cyanobacteria have the potential to produce toxins. Compared with more extensively studied plankton species, little is known about the impact of harmful benthic cyanobacteria on aquatic organisms. As demersal fish are usually in direct contact with benthic cyanobacteria, it is important to understand their interactive effects. This study investigated the physio-chemical responses of two demersal fish (Xenocypris davidi and Crucian carp) after exposure to benthic Oscillatoria (producing cylindrospermopsin, 2 × 106 cells/mL) for 7 days. Interestingly, benthic Oscillatoria had less adverse effects on X. davidi than C. carp. The two demersal fish effectively ingested Oscillatoria, but Oscillatoria cell sheathes could not be fully digested in C. carp intestines and led to growth inhibition. Oscillatoria consumption induced oxidative stress and triggered alterations in detoxification enzyme activities in the X. davidi liver. Superoxide dismutase (SOD) and glutathione reductase (GR) activities significantly increased in the C. carp liver, but catalase (CAT) and detoxification enzymes glutathione S-transferase (GST) and glutathione (GSH) activities were insignificantly changed. This suggested that C. carp may have a relatively weak detoxification capacity for toxic Oscillatoria. Oscillatoria ingestion led to more pronounced liver pathological changes in C. carp, including swelling, deformation, and loss of cytoskeleton structure. Simultaneously, fish consumption of Oscillatoria increased extracellular cylindrospermopsin concentration. These results provide valuable insights into the ecological risks associated with benthic cyanobacteria in aquatic ecosystems.
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Affiliation(s)
- Hongmin Li
- School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Yuan Yuan
- School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China
| | - Huiting Yang
- 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
| | - Xinyue Xu
- School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China
| | - Wenxia Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; College of Life Sciences, Linyi University, Linyi, Shandong, 276000, China
| | - Yanfeng Chen
- School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China
| | - Changlin Kan
- School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China
| | - Hengji Zhufu
- School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China
| | - Chen Gong
- School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China
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2
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Jin Y, Ren S, Wu Y, Zhang X, Chen Z, Xie B. Microbial community structures and bacteria-Cylindrospermopsis raciborskii interactions in Yilong Lake. FEMS Microbiol Ecol 2024; 100:fiae048. [PMID: 38578661 PMCID: PMC11057442 DOI: 10.1093/femsec/fiae048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 03/27/2024] [Accepted: 04/03/2024] [Indexed: 04/06/2024] Open
Abstract
Cylindrospermopsis raciborskii-dominated harmful algae blooms have been reported globally in recent years. However, our understanding of the ecology of C. raciborskii in natural conditions is still poor. In this study, we collected the water samples from a C. raciborskii-blooming lake, Yilong Lake, in Yunnan province, China, and used both culture-dependent and culture-independent approaches to investigate their microbial communities and the interactions between C. raciborskii and the other bacteria. The composition and diversity of microbial communities were revealed with 16S rRNA gene high-throughput sequencing data analysis. Microbial co-occurrences analysis suggests C. raciborskii may have complex associations with other bacteria. Based on co-inoculation tests, we obtained 14 strains of bacterial strains from the water samples that exhibited either algicidal or promoting effects on a strain of C. raciborskii. Two bacterial isolates exhibited a consistent performance between co-occurrence analysis and experimental results. Effects of these bacteria-algae interspecies interactions on the bloom event are discussed. All these results may provide new insights into the C. raciborskii-dominated blooms and how its interspecies relationships with other bacteria may influence the bloom events in eutrophic waters throughout the world.
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Affiliation(s)
- Yuanpei Jin
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China
| | - Sanguo Ren
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China
| | - Yichi Wu
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China
| | - Xu Zhang
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China
| | - Zhengjun Chen
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Bo Xie
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China
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3
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Li H, Kang S, Gu X, Yang H, Chen H, Mao Z, Zeng Q, Chen Y, Wang W, Gong C. The toxicological effects of life-cycle exposure to harmful benthic cyanobacteria Oscillatoria on zebrafish growth and reproduction: A comparative study with planktonic Microcystis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169302. [PMID: 38104816 DOI: 10.1016/j.scitotenv.2023.169302] [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: 09/07/2023] [Revised: 11/29/2023] [Accepted: 12/10/2023] [Indexed: 12/19/2023]
Abstract
The risks of planktonic cyanobacteria blooms have been the focus of much scientific research, but studies on the ecotoxicological effects of benthic cyanobacteria are lagging. The impacts of cyanobacteria cells on fish populations might be more complex in contrast to purified cyanotoxins or cyanobacteria extracts. This study systematically compared the chronic effects of benthic Oscillatoria sp. (producing cylindrospermopsins) and planktonic Microcystis aeruginosa (producing microcystins) on the growth and reproduction of zebrafish through life-cycle exposure (5- 90 days post fertilization). The results showed that both Oscillatoria sp. and M. aeruginosa exposure caused growth inhibition and fecundity reduction in F0 generation by disrupting sex hormone levels, delayed ovarian and sperm development, and induced pathological lesions in zebrafish gonads. Furthermore, exposure to Oscillatoria sp. or M. aeruginosa in adult zebrafish increased mortality and teratogenicity in F1 embryos (without exposure), indicating a parental transmission effect of developmental toxicity. The difference was that M. aeruginosa exposure led to significant alterations in pathways, such as tissue development, redox processes, and steroid hormone synthesis. In contrast, Oscillatoria sp. exposure primarily disrupted the PPAR signaling pathway, cell adhesion molecules, and lipid transport pathways. Interestingly, the differentially expressed genes revealed that male fish were more sensitive to harmful cyanobacteria than females, whether exposed to Oscillatoria sp. or M. aeruginosa. These findings contribute to a better mechanistic understanding of the chronic toxic effects of distinct types of harmful cyanobacteria, suggesting that the ecological risk of benthic cyanobacteria requires further attention.
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Affiliation(s)
- Hongmin Li
- School of Geography and Tourism, Qufu Normal University, Rizhao 276826, China
| | - Siqi Kang
- School of Geography and Tourism, Qufu Normal University, Rizhao 276826, China
| | - Xiaohong Gu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Huiting Yang
- 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
| | - 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
| | - Qingfei Zeng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yanfeng Chen
- School of Geography and Tourism, Qufu Normal University, Rizhao 276826, China
| | - Wenxia Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China; College of Life Sciences, Linyi University, Linyi, Shandong 276000, China
| | - Chen Gong
- School of Geography and Tourism, Qufu Normal University, Rizhao 276826, China
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Valencia-Cárdenas D, Tavares TS, Silveira R, Brandão CCS, Soares RM, Ginoris YP. Evaluation of the Removal and Effects of Cylindrospermopsin on Ripened Slow Sand Filters. Toxins (Basel) 2023; 15:543. [PMID: 37755969 PMCID: PMC10536468 DOI: 10.3390/toxins15090543] [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: 07/19/2023] [Revised: 08/24/2023] [Accepted: 08/26/2023] [Indexed: 09/28/2023] Open
Abstract
The occurrence of toxic blooms of cyanobacteria has been a matter of public health interest due to the cyanotoxins produced by these microorganisms. Cylindrospermopsin (CYN) is a cyanotoxin of particular concern due to its toxic effects on humans. This study investigated the removal and effects of CYN in ripened slow sand filters (SSFs) treating water from Paranoá Lake, Brasilia, Brazil. Four pilot-scale SSFs were ripened and operated for 74 days. Two contamination peaks with CYN were applied along the filtration run. The improvement of any of the evaluated water quality parameters was not affected by the presence of CYN in the raw water. The SSFs efficiently removed CYN, presenting concentrations lower than 0.8 µg/L in the filtered water. The microbiota of the SSFs were dominated by protozoa of the genus Euglypha and amoebas of the genera Arcella, Centropyxis, and Amoeba, together with some groups of rotifers. These microorganisms played a crucial role in removing total coliforms and E. coli. In addition, CYN was not identified as a determining factor in the microbiota composition.
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Affiliation(s)
- Daniel Valencia-Cárdenas
- Department of Civil and Environmental Engineering, Faculty of Technology, University of Brasilia, Brasilia 70910-900, Brazil; (T.S.T.); (R.S.); (C.C.S.B.); (R.M.S.)
| | | | | | | | | | - Yovanka Pérez Ginoris
- Department of Civil and Environmental Engineering, Faculty of Technology, University of Brasilia, Brasilia 70910-900, Brazil; (T.S.T.); (R.S.); (C.C.S.B.); (R.M.S.)
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5
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Shishido TK, Delbaje E, Wahlsten M, Vuori I, Jokela J, Gugger M, Fiore MF, Fewer DP. A cylindrospermopin-producing cyanobacterium isolated from a microbial mat in the Baltic Sea. Toxicon 2023:107205. [PMID: 37406865 DOI: 10.1016/j.toxicon.2023.107205] [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: 03/13/2023] [Revised: 06/12/2023] [Accepted: 06/21/2023] [Indexed: 07/07/2023]
Abstract
Toxic benthic mats of cyanobacteria are associated with water quality problems and animal poisonings around the world. A strain of the filamentous cyanobacterial genus Kamptonema was isolated from a water bloom in the Baltic Sea four decades ago and later shown to produce cylindrospermopsins. However, the exact habitat of this strain remains unclear and cylindrospermopsins have not yet been reported from water blooms in the Baltic Sea. Here, we report the isolation of Kamptonema sp. UHCC 0994 from a benthic microbial mat collected in shallow water on the coast of Helsinki. We obtained draft genome sequences for the Kamptonema spp. PCC 7926 and UHCC 0994 strains that were isolated from the Baltic Sea. These genomes were 90-96% similar to previously studied Kamptonema sp. PCC 6506 and Kamptonema formosum PCC 6407, which were isolated from benthic and North American freshwater environments, respectively. The genomes of all four Kamptonema strains encode complete cylindrospermopsin biosynthetic gene clusters. We detected the production of cylindrospermopsin and 7-epi-cylindrospermopsin in the four Kamptonema strains using high-resolution liquid chromatography mass spectrometry. The four strains encode genes for producing gas vesicles distributed in two to three different regions of their genomes. Kamptonema spp. UHCC 0994 and PCC 7926 have both retained the ability to regulate their buoyancy when grown in liquid culture. Together this suggests that these toxic cyanobacteria may exhibit a tychoplanktic lifestyle in the Baltic Sea. This study suggests that microbial mats containing cyanobacteria could be a source of environmental toxins in the Baltic Sea.
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Affiliation(s)
- Tania Keiko Shishido
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Endrews Delbaje
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland; Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, Piracicaba, 13400-970, São Paulo, Brazil
| | - Matti Wahlsten
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Inkeri Vuori
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Jouni Jokela
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Muriel Gugger
- Institut Pasteur, Université Paris Cité, Collection of Cyanobacteria, Paris, F-75015, France
| | - Marli F Fiore
- Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, Piracicaba, 13400-970, São Paulo, Brazil
| | - David P Fewer
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland.
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6
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Gu S, Zhang W, Wang F, Meng Z, Cheng Y, Geng Z, Lian F. Particle size of biochar significantly regulates the chemical speciation, transformation, and ecotoxicity of cadmium in biochar. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 320:121100. [PMID: 36669715 DOI: 10.1016/j.envpol.2023.121100] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/10/2023] [Accepted: 01/15/2023] [Indexed: 06/17/2023]
Abstract
The pyrolysis of biomass containing excessive heavy metals is likely to produce heavy metal contaminated biochar (BC). Although multiple lines of evidence indicate that higher charring temperature leads to enhanced immobilization of heavy metals in BC, we find that particle size could also play a critical role in the content of heavy metals in BC and BC ecotoxicity. Here, BC derived from cadmium (Cd) enriched rice straw was prepared at different temperatures (300-600 °C) and divided into macro-, colloidal-, and nano-sized fractions, respectively. The content and chemical forms of Cd in BC fractions as well as related algal toxicity were examined. The results show that for the same temperature BC the content of Cd followed an order of colloidal-BC > macro-BC > nano-BC; and the residual fractions of Cd significantly decreased (3.47-16.08%) while that of acid soluble and reducible fractions significantly increased (4.13-16.51% and 0.24-1.71%, respectively) with decreasing particle size of BC. Consistently, colloidal-BC exhibited the highest ecotoxicity for Scenedesmus obliquus. The acid soluble fractions of Cd in macro- and colloidal-BC played a dominating role in their algal toxicity (p < 0.05). However, the ecotoxicity of nano-BC was more dependent on the total content of Cd than specific fractions probably due to the phagocytosis by algal cells. These results indicate that the chemical forms and ecotoxicity of Cd in BC could be remarkably modified by its particle size, which has profound implications for understanding the behavior and potential risk of heavy metal contaminated BC in the environment.
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Affiliation(s)
- Shiguo Gu
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China; College of Civil and Architecture Engineering, Chuzhou University, Chuzhou, Anhui, 239000, China
| | - Wei Zhang
- School of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Fei Wang
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Zhanhang Meng
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Yu Cheng
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Zexuan Geng
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Fei Lian
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China.
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7
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Osburn FS, Wagner ND, Taylor RB, Chambliss CK, Brooks BW, Scott JT. The effects of salinity and N:P on N-rich toxins by both an N-fixing and non-N-fixing cyanobacteria. LIMNOLOGY AND OCEANOGRAPHY LETTERS 2023; 8:162-172. [PMID: 36777312 PMCID: PMC9915339 DOI: 10.1002/lol2.10234] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 12/08/2021] [Indexed: 06/18/2023]
Abstract
Freshwater ecosystems are experiencing increased salinization. Adaptive management of harmful algal blooms (HABs) contribute to eutrophication/salinization interactions through the hydrologic transport of blooms to coastal environments. We examined how nutrients and salinity interact to affect growth, elemental composition, and cyanotoxin production/release in two common HAB genera. Microcystis aeruginosa (non-nitrogen (N)-fixer and microcystin-LR producer; MC-LR) and Aphanizomenon flos-aquae (N-fixer and cylindrospermopsin producer; CYN) were grown in N:phosphorus (N:P) 4 and 50 (by atom) for 21 and 33 days, respectively, then dosed with a salinity gradient (0 - 10.5 g L-1). Both total MC-LR and CYN were correlated with particulate N. We found Microcystis MC-LR production and release was affected by salinity only in the N:P 50 treatment. However, Aphanizomenon CYN production and release was affected by salinity regardless of N availability. Our results highlight how cyanotoxin production and release across the freshwater - marine continuum are controlled by eco-physiological differences between N-acquisition traits.
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Affiliation(s)
- Felicia S. Osburn
- Department of Biology, Baylor University, Waco TX USA
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco TX USA
| | - Nicole D. Wagner
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco TX USA
| | - Raegyn B. Taylor
- Department of Chemistry and Biochemistry, Baylor University, Waco TX USA
| | - C. Kevin Chambliss
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco TX USA
- Department of Chemistry and Biochemistry, Baylor University, Waco TX USA
- The Institute for Ecological, Earth, and Environmental Sciences, Baylor University, Waco TX USA
| | - Bryan W. Brooks
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco TX USA
- The Institute for Ecological, Earth, and Environmental Sciences, Baylor University, Waco TX USA
- Department of Environmental Science, Baylor University, Waco TX USA
- Institute of Biomedical Studies, Baylor University, Waco TX USA
| | - J. Thad Scott
- Department of Biology, Baylor University, Waco TX USA
- Center for Reservoir and Aquatic Systems Research, Baylor University, Waco TX USA
- The Institute for Ecological, Earth, and Environmental Sciences, Baylor University, Waco TX USA
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8
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Wagner ND, Osburn FS, Taylor RB, Back JA, Chambliss CK, Brooks BW, Scott JT. Diazotrophy modulates cyanobacteria stoichiometry through functional traits that determine bloom magnitude and toxin production. LIMNOLOGY AND OCEANOGRAPHY 2023; 68:348-360. [PMID: 36819961 PMCID: PMC9937718 DOI: 10.1002/lno.12273] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 11/10/2022] [Indexed: 06/18/2023]
Abstract
Harmful cyanobacterial blooms are an increasing threat to water quality. The interactions between two eco-physiological functional traits of cyanobacteria, diazotrophy (nitrogen (N)-fixation) and N-rich cyanotoxin synthesis, have never been examined in a stoichiometric explicit manner. We explored how a gradient of resource N:phosphorus (P) affects the biomass, N, P stoichiometry, light-harvesting pigments, and cylindrospermopsin production in a N-fixing cyanobacterium, Aphanizomenon. Low N:P Aphanizomenon cultures produced the same biomass as populations grown in high N:P cultures. The biomass accumulation determined by carbon, indicated low N:P Aphanizomenon cultures did not have a N-fixation growth tradeoff, in contrast to some other diazotrophs that maintain stoichiometric N homeostasis at the expense of growth. However, N-fixing Aphanizomenon populations produced less particulate cylindrospermopsin and had undetectable dissolved cylindrospermopsin compared to non-N-fixing populations. The pattern of low to high cyanotoxin cell quotas across an N:P gradient in the diazotrophic cylindrospermopsin producer is similar to the cyanotoxin cell quota response in non-diazotrophic cyanobacteria. We suggest that diazotrophic cyanobacteria may be characterized into two broad functional groups, the N-storage-strategists and the growth-strategists, which use N-fixation differently and may determine patterns of bloom magnitude and toxin production in nature.
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Affiliation(s)
- Nicole D Wagner
- Department of Biological Sciences, Oakland University, Rochester MI, 48326, USA
- Center for Reservoir and Aquatic System Research, Baylor University, Waco TX, 76798, USA
| | - Felicia S Osburn
- Center for Reservoir and Aquatic System Research, Baylor University, Waco TX, 76798, USA
- Department of Biology, Baylor University, Waco TX, 76798, USA
- Department of Biology, University of Central Arkansas, Conway AR, 72035, USA
| | - Raegyn B Taylor
- Center for Reservoir and Aquatic System Research, Baylor University, Waco TX, 76798, USA
- Department of Chemistry and Biochemistry, Baylor University, Waco TX, 76798, USA
- United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, 19038, USA
| | - Jeffrey A Back
- Center for Reservoir and Aquatic System Research, Baylor University, Waco TX, 76798, USA
| | - C Kevin Chambliss
- Center for Reservoir and Aquatic System Research, Baylor University, Waco TX, 76798, USA
- Department of Chemistry and Biochemistry, Baylor University, Waco TX, 76798, USA
| | - Bryan W Brooks
- Center for Reservoir and Aquatic System Research, Baylor University, Waco TX, 76798, USA
- Department of Environmental Science, Baylor University, Waco TX, 76798, USA
| | - J Thad Scott
- Center for Reservoir and Aquatic System Research, Baylor University, Waco TX, 76798, USA
- Department of Biology, Baylor University, Waco TX, 76798, USA
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9
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Vilar M, Ferrão-Filho A. (Eco)Toxicology of Cyanobacteria and Cyanotoxins: From Environmental Dynamics to Adverse Effects. TOXICS 2022; 10:toxics10110648. [PMID: 36355940 PMCID: PMC9694381 DOI: 10.3390/toxics10110648] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 10/24/2022] [Indexed: 06/01/2023]
Abstract
The problem of artificial eutrophication, together with the effects of climate changes has led to an increase in the frequency of the occurrence of cyanobacterial blooms [...].
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Affiliation(s)
- Mauro Vilar
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Carlos Chagas Filho Avenue, Rio de Janeiro 21949-902, RJ, Brazil
| | - Aloysio Ferrão-Filho
- Laboratory of Evaluation and Promotion of Environmental Health, Instituto Oswaldo Cruz, FIOCRUZ, Brasil Avenue, 4365, Manguinhos, Rio de Janeiro 21045-900, RJ, Brazil
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10
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Dreher TW, Foss AJ, Davis EW, Mueller RS. 7-epi-cylindrospermopsin and microcystin producers among diverse Anabaena/Dolichospermum/Aphanizomenon CyanoHABs in Oregon, USA. HARMFUL ALGAE 2022; 116:102241. [PMID: 35710201 DOI: 10.1016/j.hal.2022.102241] [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: 01/11/2022] [Revised: 03/18/2022] [Accepted: 04/27/2022] [Indexed: 06/15/2023]
Abstract
Several genomes of Nostocales ADA clade members from the US Pacific Northwest were recently sequenced. Biosynthetic genes for microcystin, cylindrospermopsin or anatoxin-a were present in 7 of the 15 Dolichospermum/Anabaena strains and none of the 5 Aphanizomenon flos-aquae (AFA) strains. Toxin analyses (ELISA and LC-MS/MS) were conducted to quantitate and identify microcystin (MC) and cylindrospermopsin (CYN) congeners/analogs in samples dominated by Dolichospermum spp. of known genome sequence. MC-LR was the main congener produced by Dolichospermum spp. from Junipers Reservoir, Lake Billy Chinook and Odell Lake, while a congener provisionally identified as [Dha7]MC-HtyR was produced by a Dolichospermum sp. in Detroit Reservoir. A second Dolichospermum sp. from Detroit Reservoir was found to produce 7-epi-CYN, with 7-deoxy-CYN also present, but no CYN. The monitoring history of each of these lakes indicates the capacity for high levels of cyanotoxins during periods when Dolichospermum spp. are the dominant cyanobacteria. The diversity of ADA strains found in the US Pacific NW emphasizes the importance of these cyanobacteria as potentially toxic HAB formers in this temperate climatic region. Our results linking congener and genetic identity add data points that will help guide development of improved tools for predicting congener specificity from cyanotoxin gene sequences.
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Affiliation(s)
- Theo W Dreher
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA.
| | - Amanda J Foss
- GreenWater Laboratories, 205 Zeagler Drive, Suite 302, Palatka, FL 32177, USA.
| | - Edward W Davis
- Center for Quantitative Life Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Ryan S Mueller
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA
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11
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Li H, Gu X, Chen H, Mao Z, Zeng Q, Yang H, Kan K. Comparative toxicological effects of planktonic Microcystis and benthic Oscillatoria on zebrafish embryonic development: Implications for cyanobacteria risk assessment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 274:115852. [PMID: 33246764 DOI: 10.1016/j.envpol.2020.115852] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/11/2020] [Accepted: 10/12/2020] [Indexed: 06/12/2023]
Abstract
Planktonic and benthic cyanobacteria blooms are increasing in frequency in recent years. Although many studies have focused on the effects of purified toxins or cyanobacteria extracts on fish developments, the more complex impacts of cyanobacteria cells on fish populations are still considered insufficient. This study compared the toxicological effects of harmful planktonic Microcystis and benthic Oscillatoria on zebrafish (Danio rerio) early stages of development. Zebrafish embryos, at 1-2 h post fertilization (hpf), were exposed to 5, 10, and 20 × 105 cells/mL Microcystis (producing microcystins) or Oscillatoria (producing cylindrospermopsins) until 96 hpf. The results indicated that the effects of benthic Oscillatoria on embryonic development of zebrafish were different from those of planktonic Microcystis. Reduced hatching rates, increased mortality, depressed heart rates and elevated malformation rates were observed following exposures to increased concentrations of Microcystis, whilst Oscillatoria exposures only caused yolk sac edemas. Exposure to a high concentration of Microcystis induced severe oxidative damage, growth inhibition and transcriptional downregulations of genes (GH, GHR1, IGF1, IGF1rb) associated with the growth hormone/insulin-like growth factor (GH/IGF) axis. Although Oscillatoria exposure did not affect the body growth, it obviously enhanced the antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and up-regulated the expressions of several oxidative stress-related genes. Discrepancies in the developmental toxicity caused by Microcystis and Oscillatoria may not only attributed to the different secondary metabolites they secrete, but also to the different adhesion behaviors of algal cells on embryonic chorion. These results suggested that harmful cyanobacteria cells could influence the successful recruitment of fish, while the effects of benthic cyanobacteria should not be ignored. It also highlighted that the necessity for further investigating the ecotoxicity of intact cyanobacterial samples when assessing the risk of cyanobacterial blooms.
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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; Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian, 223300, China.
| | - Huihui Chen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
| | - Zhigang Mao
- 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
| | - Huiting Yang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; Inner Mongolia Key Laboratory of Environmental Pollution Control & Waste Resource Reuse, School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, China
| | - Kecong Kan
- 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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12
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Yang Y, Yu G, Chen Y, Jia N, Li R. Four decades of progress in cylindrospermopsin research: The ins and outs of a potent cyanotoxin. JOURNAL OF HAZARDOUS MATERIALS 2021; 406:124653. [PMID: 33321325 DOI: 10.1016/j.jhazmat.2020.124653] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
The cyanotoxin cylindrospermopsin (CYN), a toxic metabolite from cyanobacteria, is of particular concern due to its cosmopolitan occurrence, aquatic bioaccumulation, and multi-organ toxicity. CYN is the second most often recorded cyanotoxin worldwide, and cases of human morbidity and animal mortality are associated with ingestion of CYN contaminated water. The toxin poses a great challenge for drinking water treatment plants and public health authorities. CYN, with the major toxicity manifested in the liver, is cytotoxic, genotoxic, immunotoxic, neurotoxic and may be carcinogenic. Adverse effects are also reported for endocrine and developmental processes. We present a comprehensive review of CYN over the past four decades since its first reported poisoning event, highlighting its global occurrence, biosynthesis, toxicology, removal, and monitoring. In addition, current data gaps are identified, and future directions for CYN research are outlined. This review is beneficial for understanding the ins and outs of this environmental pollutant, and for robustly assessing health hazards posed by CYN exposure to humans and other organisms.
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Affiliation(s)
- Yiming Yang
- Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Guangzhou, Guangdong 510182, China
| | - Gongliang Yu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Youxin Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Nannan Jia
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Renhui Li
- College of Life and Environmental Science, Wenzhou University, Wenzhou, Zhejiang 325035, China.
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13
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Moraes ACN, Freire DS, Habibi H, Lowe J, Magalhães VF. Cylindrospermopsin impairs tubular transport function in kidney cells LLC-PK1. Toxicol Lett 2021; 344:26-33. [PMID: 33689780 DOI: 10.1016/j.toxlet.2021.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 01/03/2023]
Abstract
Cylindrospermopsin (CYN) has been involved in cases of poisoning in humans following ingestion. Studies have demonstrated that the kidney is the most affected organ. CYN exposure leads to low-molecular-weight proteinuria and increased excretions of the tubular enzymes in mice, suggesting the damage caused by CYN is mainly tubular. However, the mechanism involved in CYN nephrotoxicity remains unknown. Thus, in order to evaluate the effects of CYN exposure (0.1, 0.5 and 1.0 μg/mL) on tubular renal cells LLC-PK1 distinct mechanisms were analyzed by assessing cell death using flow cytometry, albumin uptake by fluorescence analysis, Na+/K+-ATPase activity by a colorimetric method, RT-qPCR of genes related to tubular transport and function as well as internalization of CYN by ELISA. In this study, CYN was found to induce necrosis in all concentrations. CYN also decreased albumin uptake as well as downregulated megalin and dab2 expression, both proteins involved in albumin endocytosis process. Moreover, CYN appears to be internalized by renal tubular cells through a receptor-mediated endocytosis. Finally, the present study demonstrates that CYN is responsible for disrupting tubular cell transport and function in LLC-PK1 cells.
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Affiliation(s)
- A C N Moraes
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - D S Freire
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - H Habibi
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - J Lowe
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - V F Magalhães
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
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14
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Méjean A, Ploux O. Biosynthesis of Cylindrospermopsin in Cyanobacteria: Characterization of CyrJ the Sulfotransferase. JOURNAL OF NATURAL PRODUCTS 2021; 84:408-416. [PMID: 33439646 DOI: 10.1021/acs.jnatprod.0c01089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
7-Deoxy-desulfo-cylindrospermopsin was purified at small-scale from the supernatant of a culture of the cyanobacterium Oscillatoria sp. PCC 10702. This metabolite was obtained in a pure form using a three-step chromatographic procedure, and its identity was confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). LC-MS quantification showed that this metabolite was excreted in the culture medium of Oscillatoria sp. PCC 10702. Isotopic incorporation studies using [2-13C,15N]glycine, a cylindrospermopsin precursor, and Oscillatoria sp. PCC 10702 cells showed that glycine was incorporated into 7-deoxy-desulfo-cylindrospermopsin, 7-deoxy-cylindrospermopsin, 7-epi-cylindrospermopsin, and cylindrospermopsin. The isotopic incorporation rate was consistent with the following metabolic flux: 7-deoxy-desulfo-cylindrospermopsin → 7-deoxy-cylindrospermopsin → 7-epi-cylindrospermopsin and cylindrospermopsin. We have cloned the cyrJ gene into an expression vector and overproduced the putative sulfotransferase CyrJ in Escherichia coli. The purified protein CyrJ catalyzed, in vitro, the transfer of a sulfonate group from 3'-phosphoadenosine-5'-phosphosulfate (PAPS) to 7-deoxy-desulfo-cylindrospermopsin to give 7-deoxy-cylindrospermopsin. Kinetic analysis afforded the following apparent constants: KM app. (PAPS) = 0.12 μM, Vmax app. = 20 nM/min, KM app. (7-deoxy-desulfo-cylindrospermopsin) = 0.12 μM, and KI app. (7-deoxy-desulfo-cylindrospermopsin) = 4.1 μM. Preliminary data suggested that CyrJ catalyzed the reaction through a ternary-complex kinetic mechanism. All these data confirmed that CyrJ catalyzed a sulfotransfer during the penultimate step of the biosynthesis of cylindrospermopsin.
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Affiliation(s)
- Annick Méjean
- LIED, UMR 8236 CNRS, Université de Paris, 75205 Paris, Cedex 13, France
| | - Olivier Ploux
- LIED, UMR 8236 CNRS, Université de Paris, 75205 Paris, Cedex 13, France
- Chimie ParisTech, PSL, 75005 Paris, France
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15
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González-Blanco C, Dörr FA, Albuquerque R, Onuki J, Pinto E. Alternative Isolation Protocol for Desulfo and Zwitterionic Cylindrospermopsin Alkaloids and Comparison of Their Toxicity in HepG2 Cells. Molecules 2020; 25:molecules25133027. [PMID: 32630766 PMCID: PMC7412431 DOI: 10.3390/molecules25133027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 12/26/2022] Open
Abstract
The term cylindrospermopsins (CYNs) refers to a structurally related class of cyanobacterial metabolites comprised of a tricyclic guanidine group and a hydroxymethyluracil moiety. Most reports in environmental aquatic samples refer to cylindrospermopsin (CYN), and reports on other CYN alkaloids are scarce, due, in part, to a lack of versatile isolation protocols. Thus, using commercially available solid phase extraction (SPE) cartridges, we optimized an isolation protocol for the complete recovery of CYN, 7-deoxy-cylindrospermopsin (7D-CYN) and 7-deoxy-desulfo-cylindrospermopsin (7D-desulfo-CYN) from the same aliquot. The isolation protocol was adaptable depending on the nature of the sample (solid biomass, culture broth or environmental water sample) and tolerates up to 4 L of dense culture broth or 400 mg of lyophilized biomass. To quantitate the CYN alkaloids, we validated an LC-DAD-MS2 method, which takes advantage of the UV absorption of the uracil group (λ 262 nm). Using electrospray ionization (ESI) in a positive ion mode, the high-resolution MS1 data confirms the presence of the protonated alkaloids, and the MS2 fragment assignment is reported as complementary proof of the molecular structure of the CYNs. We isolated three CYN alkaloids with different water solubility using the same lyophilized sample, with a purity that ranged from 95% to 99%. The biological activity of the purified CYNs, along with a synthetic degradation product of CYN (desulfo-cylindrospermopsin), was evaluated by assessing necrosis and apoptosis in vitro using flow cytometry. CYN’s lethal potency in HepG2 cells was greater than the other analogs, due to the presence of all four functional groups: guanidine, uracil, C-7 hydroxyl and the sulfate residue.
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Affiliation(s)
- Carlos González-Blanco
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
- Laboratory of Development and Innovation, Butantan Institute, Av. Vital Brasil, 1500, São Paulo 05503-900, SP, Brazil;
- Sección de Toxicología, Departamento de Ciencias Forenses, Organismo de Investigación Judicial, Heredia 40801, Costa Rica
| | - Felipe Augusto Dörr
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
| | - Renata Albuquerque
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
| | - Janice Onuki
- Laboratory of Development and Innovation, Butantan Institute, Av. Vital Brasil, 1500, São Paulo 05503-900, SP, Brazil;
| | - Ernani Pinto
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-900, SP, Brazil; (C.G.-B.); (F.A.D.); (R.A.)
- Centre for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba 13416-000, SP, Brazil
- Correspondence: ; Tel.: +55-193429-4779
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16
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Xiao M, Hamilton DP, Chuang A, Burford MA. Intra-population strain variation in phosphorus storage strategies of the freshwater cyanobacterium Raphidiopsis raciborskii. FEMS Microbiol Ecol 2020; 96:5837077. [DOI: 10.1093/femsec/fiaa092] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/12/2020] [Indexed: 01/10/2023] Open
Abstract
ABSTRACT
Several cyanobacteria, including diazotrophic Raphidiopsis raciborskii, can form harmful blooms when dissolved inorganic phosphorus concentrations are very low. We hypothesized that R. raciborskii strains would vary in phosphorus (P) allocations to cell growth and storage, providing resilience of populations to continuously low or variable P supplies. We tested this hypothesis using six toxic strains (producing cylindrospermopsins) isolated from a field population using batch monocultures with and without P and dissolved inorganic nitrogen (DIN). Treatments replete with DIN, irrespective of P addition, had similar exponential growth rates for individual strains. P storage capacity varied 4-fold among strains and was significantly higher in DIN-free treatments than in replete treatments. P was stored by all R. raciborskii strains, in preference to allocation to increase growth rates. P stores decreased with increased growth rate across strains, but weeere not related to the time to P starvation in P-free treatments. The storage capacity of R. raciborskii, combined with strategies to efficiently uptake P, means that P controls may not control R. raciborskii populations in the short term. Intra-population strain variation in P storage capacity will need to be reflected in process-based models to predict blooms of R. raciborskii and other cyanobacteria adapted to low-P conditions.
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Affiliation(s)
- Man Xiao
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, QLD 4111, Australia
| | - David P Hamilton
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, QLD 4111, Australia
| | - Ann Chuang
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, QLD 4111, Australia
| | - Michele A Burford
- Australian Rivers Institute, Griffith University, 170 Kessels Road, Nathan, QLD 4111, Australia
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17
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Huguet A, Lanceleur R, Quenault H, Le Hégarat L, Fessard V. Identification of key pathways involved in the toxic response of the cyanobacterial toxin cylindrospermopsin in human hepatic HepaRG cells. Toxicol In Vitro 2019; 58:69-77. [PMID: 30905859 DOI: 10.1016/j.tiv.2019.03.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/07/2019] [Accepted: 03/20/2019] [Indexed: 02/07/2023]
Abstract
The hepatotoxin cylindrospermopsin (CYN) has been involved in cases of poisoning in humans following ingestion. As its liver toxicity process is complex, we studied the transcriptomic profile of HepaRG cells exposed to CYN. The affected pathways were confirmed through the expression of key genes and the investigation of toxicity markers. In addition, CYP450 activities and cell redox homeostasis were investigated following acute and repeated exposure. CYN induced the down-regulation of genes involved in xenobiotic metabolism and cell cycle progression. There was cell cycle disturbance characterised by an accumulation of G1/S and G2/M cells and an increase in phospho-H3-positive cells. This was linked to the induction of DNA damage demonstrated by an increase in γH2AX-positive cells as well as an accumulation of sub-G1 cells indicating apoptosis but not involving caspase-3. While glutathione (GSH) content sharply decreased following acute exposure to CYN, it increased following repeated exposure, reflecting an adaptive response of cell redox homeostasis. However, our data also suggested that CYN induced the down-regulation of phase I and II metabolism gene products, and CYP450 activities were affected following both acute and repeated exposure to CYN. Our study indicated that repeated exposure of liver cells to low concentrations of CYN may affect their detoxification capacities.
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Affiliation(s)
- Antoine Huguet
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, 10B rue Claude Bourgelat, 35306 Fougères, France.
| | - Rachelle Lanceleur
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, 10B rue Claude Bourgelat, 35306 Fougères, France
| | - Hélène Quenault
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Ploufragan-Plouzané Laboratory, Viral Genetic and Biosecurity Unit, 22440 Ploufragan, France
| | - Ludovic Le Hégarat
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, 10B rue Claude Bourgelat, 35306 Fougères, France
| | - Valérie Fessard
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Fougères Laboratory, Toxicology of Contaminants Unit, 10B rue Claude Bourgelat, 35306 Fougères, France
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18
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Jin Y, Zhang S, Xu H, Ma C, Sun J, Li H, Pei H. Application of N-TiO 2 for visible-light photocatalytic degradation of Cylindrospermopsis raciborskii - More difficult than that for photodegradation of Microcystis aeruginosa ? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 245:642-650. [PMID: 30481678 DOI: 10.1016/j.envpol.2018.11.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 06/09/2023]
Abstract
Nowadays Cylindrospermopsis raciborskii (C. raciborskii) and the metabolites produced, such as cylindrospermopsin (CYN), pose a serious threat to the ecosystem. Advanced oxidation technologies have been verified as constituting a very promising means to eliminate the risk from harmful algae. But so far little research has focused on the visible-light photocatalytic destruction of C. raciborskii cells and the degradation of their metabolites. In our study, N-doped TiO2 (N-TiO2) was used to degrade C. raciborskii and the degradation was compared with that of the Microcystis aeruginosa (M. aeruginosa). Results showed that although the photodegradation of C. raciborskii was more difficult than that of M. aeruginosa, the treatment with N-TiO2 was still satisfactory. After adding 200 mg/L N-TiO2, C. raciborskii cells (5 × 106 cells/mL) were completely destroyed within 20 h under visible light irradiation, and nearly 90% of the organic matter and CYN in the suspensions were also degraded, thereby markedly improving the water quality. The photocatalytic process starts with damage to the cell membrane resulting in the leakage of internal components. Subsequently, the leaked metabolites were oxidised by the reactive oxidizing species produced by N-TiO2. Thus, the application of N-TiO2 is a promising method for the treatment of C. raciborskii.
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Affiliation(s)
- Yan Jin
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Shasha Zhang
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Hangzhou Xu
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Chunxia Ma
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Jiongming Sun
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Hongmin Li
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Haiyan Pei
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China; Shandong Provincial Engineering Centre for Environmental Science and Technology, Jinan, 250061, China.
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Development of Time-Resolved Fluoroimmunoassay for Detection of Cylindrospermopsin Using Its Novel Monoclonal Antibodies. Toxins (Basel) 2018; 10:toxins10070255. [PMID: 29933618 PMCID: PMC6070832 DOI: 10.3390/toxins10070255] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/13/2018] [Accepted: 06/15/2018] [Indexed: 12/11/2022] Open
Abstract
Cylindrospermopsin (CYN) is a cyanotoxin that is of particular concern for its potential toxicity to human and animal health and ecological consequences due to contamination of drinking water. The increasing emergence of CYN around the world has led to urgent development of rapid and high-throughput methods for its detection in water. In this study, a highly sensitive monoclonal antibody N8 was produced and characterized for CYN detection through the development of a direct competitive time-resolved fluorescence immunoassay (TRFIA). The newly developed TRFIA exhibited a typical sigmoidal response for CYN at concentrations of 0.01–100 ng mL−1, with a wide quantitative range between 0.1 and 50 ng mL−1. The detection limit of the method was calculated to be 0.02 ng mL−1, which is well below the guideline value of 1 μg L−1 and is sensitive enough to provide an early warning of the occurrence of CYN-producing cyanobacterial blooms. The newly developed TRFIA also displayed good precision and accuracy, as evidenced by low coefficients of variation (4.1–6.5%). Recoveries ranging from 92.6% to 108.8% were observed upon the analysis of CYN-spiked water samples. Moreover, comparison of the TRIFA with an ELISA kit through testing 76 water samples and 15 Cylindrospermopsis cultures yielded a correlation r2 value of 0.963, implying that the novel immunoassay was reliable for the detection of CYN in water and algal samples.
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20
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Yang Y, Chen Y, Cai F, Liu X, Wang Y, Li R. Toxicity-associated changes in the invasive cyanobacterium Cylindrospermopsis raciborskii in response to nitrogen fluctuations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 237:1041-1049. [PMID: 29153475 DOI: 10.1016/j.envpol.2017.11.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 10/27/2017] [Accepted: 11/06/2017] [Indexed: 06/07/2023]
Abstract
The cyanobacterium Cylindrospermopsis raciborskii is of particular concern due to its ability to fix nitrogen (N), sporadic bloom, potential toxicity and apparent invasiveness. However, the toxicity associated behavior and response of toxic C. raciborskii under N fluctuations in water have been poorly investigated. The present study initiated based on the field survey in which Cylindrospermopsis species was found to have a high fitness under nitrate concentrations fluctuating from 0.02 mg L-1 to 2.90 mg L-1 in Chinese freshwater lakes. Examination on the role of short-term N fluctuations was conducted in two C. raciborskii strains which were exposed to a range of N concentrations supplied in two patterns, namely one-time pattern and ten-time pattern in which the equal amount of N was divided into ten-time accretions. The results showed the growth of both strains were not vulnerable to the transient nutrient fluctuations. The toxic strain showed considerable toxicological flexibility with the highest yield of cylindrospermopsin (CYN) obtained in the absence of N and the lowest in full medium. Generally, larger amounts of total CYN were observed at lower N levels, indicating that N deficiency promoted the intracellular accumulation and simultaneously restrained the extracellular release of CYN. Furthermore, CYN production was significantly different in two N supply patterns. The maximum quotas of intracellular and extracellular CYN in one-time pattern were respectively 2.79-3.53 and 3.94-7.20 times higher compared to the ten-time pattern. To our knowledge, our results are the first evidence of toxicity variations of C. raciborskii to the impermanent N fluctuations, shedding new light on its toxicological plasticity.
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Affiliation(s)
- Yiming Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Youxin Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fangfang Cai
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiang Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yilang Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Renhui Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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21
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Li H, Pei H, Xu H, Jin Y, Sun J. Behavior of Cylindrospermopsis raciborskii during coagulation and sludge storage - higher potential risk of toxin release than Microcystis aeruginosa? JOURNAL OF HAZARDOUS MATERIALS 2018; 347:307-316. [PMID: 29331810 DOI: 10.1016/j.jhazmat.2018.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 01/03/2018] [Accepted: 01/04/2018] [Indexed: 06/07/2023]
Abstract
Owing to the global warming and its strong adaptability, Cylindrospermopsis raciborskii has spread world-wide. However, as one of toxic cyanobacteria in many drinking water sources, it has not been drawn proper consideration in drinking water treatment plants so far. The investigation aimed at unveiling the fate of C. raciborskii during polyaluminum ferric chloride (PAFC) coagulation and sludge storage, revealing its differences from Microcystis aeruginosa. Results showed that C. raciborskii cells were effectively removed intactly under optimum coagulation conditions, but PAFC at higher dosages (>10 mg/L) triggered additional cylindrospermopsins release. In sludge storage, coagulated C. raciborskii cells suffered severe oxidative damage, leading to significant cylindrospermopsins release after day 6. C. raciborskii manifested different behaviors from M. aeruginosa which cells didn't release much microcystins during coagulation and sludge storage. This was mostly due to their differences in physiology and morphology. In flocs, M. aeruginosa could be enveloped by coagulant which can protect cells against the nasty attack from outside, whereas C. raciborskii with long filaments was hard to be wrapped and prone to suffering oxidative damage. These results confirmed C. raciborskii had a higher risk of toxin release in water production process than M. aeruginosa, which should deserve more attention.
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Affiliation(s)
- Hongmin Li
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Haiyan Pei
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China.
| | - Hangzhou Xu
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Yan Jin
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Jiongming Sun
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
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22
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Turner AD, Dhanji-Rapkova M, O'Neill A, Coates L, Lewis A, Lewis K. Analysis of Microcystins in Cyanobacterial Blooms from Freshwater Bodies in England. Toxins (Basel) 2018; 10:E39. [PMID: 29324646 PMCID: PMC5793126 DOI: 10.3390/toxins10010039] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/02/2018] [Accepted: 01/08/2018] [Indexed: 01/09/2023] Open
Abstract
Cyanobacterial blooms in freshwater bodies in England are currently monitored reactively, with samples containing more than 20,000 cells/mL of potentially toxin-producing species by light microscopy resulting in action by the water body owner. Whilst significantly reducing the risk of microcystin exposure, there is little data describing the levels of these toxins present in cyanobacterial blooms. This study focused on the quantitative LC-MS/MS analysis of microcystins in freshwater samples, collected across England during 2016 and found to contain potentially toxin-producing cyanobacteria. More than 50% of samples contained quantifiable concentrations of microcystins, with approximately 13% exceeding the WHO medium health threshold of 20 μg/L. Toxic samples were confirmed over a nine-month period, with a clear increase in toxins during late summer, but with no apparent geographical patterns. No statistical relationships were found between total toxin concentrations and environmental parameters. Complex toxin profiles were determined and profile clusters were unrelated to cyanobacterial species, although a dominance of MC-RR was determined in water samples from sites associated with lower rainfall. 100% of samples with toxins above the 20 μg/L limit contained cell densities above 20,000 cells/mL or cyanobacterial scum, showing the current regime is suitable for public health. Conversely, with only 18% of cell density threshold samples having total microcystins above 20 μg/L, there is the potential for reactive water closures to unnecessarily impact upon the socio-economics of the local population. In the future, routine analysis of bloom samples by LC-MS/MS would provide a beneficial confirmatory approach to the current microscopic assessment, aiding both public health and the needs of water users and industry.
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Affiliation(s)
- Andrew D Turner
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Monika Dhanji-Rapkova
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Alison O'Neill
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Lewis Coates
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Adam Lewis
- Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Katy Lewis
- Environment Agency, Horizon House, Deanery Rd, Bristol BS1 5AH, UK.
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23
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Funari E, Manganelli M, Buratti FM, Testai E. Cyanobacteria blooms in water: Italian guidelines to assess and manage the risk associated to bathing and recreational activities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 598:867-880. [PMID: 28458204 DOI: 10.1016/j.scitotenv.2017.03.232] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/23/2017] [Accepted: 03/25/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacteria thrive in many aquatic environments, where they can produce cyanotoxins with different toxicological profile. Anthropic pressure and climate changes are causing the expansion in terms of time and space of their blooms, increasing the concerns for human health in several exposure scenarios. Here the update of the Italian guidelines for the management of cyanobacterial blooms in bathing water is presented. A risk-based approach has been developed according to the current scientific knowledge on cyanobacteria distribution in the Italian Lakes and on chemical, toxicological and epidemiological aspects of different cyanotoxins, summarized in the first part of the paper. Oral, dermal and inhalation exposure to cyanotoxins, during recreational activities, are individually examined, to develop a framework of thresholds and actions aimed at preventing harmful effects for bathers. Guidelines, also by comparing international guidance values and/or guidelines, provide criteria to plan environmental monitoring activities, health surveillance and public communication systems. Finally the still important scientific gaps and research needs are highlighted.
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Affiliation(s)
- Enzo Funari
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Maura Manganelli
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Franca M Buratti
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Emanuela Testai
- Istituto Superiore di Sanità, Dept. of Environment and Health, Viale Regina Elena 299, 00161 Rome, Italy.
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24
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Gaget V, Lau M, Sendall B, Froscio S, Humpage AR. Cyanotoxins: Which detection technique for an optimum risk assessment? WATER RESEARCH 2017; 118:227-238. [PMID: 28433693 DOI: 10.1016/j.watres.2017.04.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 04/04/2017] [Accepted: 04/08/2017] [Indexed: 05/28/2023]
Abstract
The presence of toxigenic cyanobacteria (blue-green algae) in drinking water reservoirs poses a risk to human and animal health worldwide. Guidelines and health alert levels have been issued in the Australian Drinking Water Guidelines for three major toxins, which are therefore the subject of routine monitoring: microcystin, cylindrospermopsin and saxitoxin. While it is agreed that these toxic compounds should be monitored closely, the routine surveillance of these bioactive chemicals can be done in various ways and deciding which technique to use can therefore be challenging. This study compared several assays available for the detection of these toxins and their producers in environmental samples: microscopy (for identification and enumeration of cyanobacteria), ELISA (Enzyme-Linked ImmunoSorbant Assay), PPIA (Protein phosphatase inhibition assay), PSI (Protein synthesis inhibition), chemical analysis and PCR (Polymerase Chain Reaction). Results showed that there was generally a good correlation between the presence of potentially toxigenic cyanobacteria and the detection of the toxin by ELISA. Nevertheless data suggest that cell numbers and toxin concentrations measured in bioassays do not necessarily correlate and that enumeration of potentially toxic cyanobacteria by microscopy, while commonly used for monitoring and risk assessment, is not the best indicator of real toxin exposure. The concentrations of saxitoxins quantified by ELISA were significantly different than those measured by LC-MS, while results were comparable in both assays for microcystin and cylindrospermopsin. The evaluation of these analytical methods led to the conclusion that there is no "gold standard" technique for the detection of the aforementioned cyanotoxins but that the choice of detection assay depends on cost, practicality, reliability and comparability of results and essentially on the question to be answered, notably on toxin exposure potential.
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Affiliation(s)
- Virginie Gaget
- South Australia Water Corporation, Australian Water Quality Centre, 250 Victoria Square, Adelaide, SA 5000, Australia.
| | - Melody Lau
- South Australia Water Corporation, Australian Water Quality Centre, 250 Victoria Square, Adelaide, SA 5000, Australia
| | - Barbara Sendall
- Queensland Health Forensic and Scientific Services, 39 Kessels Road, Coopers Plains, QLD 4108, Australia
| | - Suzanne Froscio
- South Australia Water Corporation, Australian Water Quality Centre, 250 Victoria Square, Adelaide, SA 5000, Australia
| | - Andrew R Humpage
- South Australia Water Corporation, Australian Water Quality Centre, 250 Victoria Square, Adelaide, SA 5000, Australia
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25
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Buratti FM, Manganelli M, Vichi S, Stefanelli M, Scardala S, Testai E, Funari E. Cyanotoxins: producing organisms, occurrence, toxicity, mechanism of action and human health toxicological risk evaluation. Arch Toxicol 2017; 91:1049-1130. [DOI: 10.1007/s00204-016-1913-6] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/13/2016] [Indexed: 12/11/2022]
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26
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Variations of Growth and Toxin Yield in Cylindrospermopsis raciborskii under Different Phosphorus Concentrations. Toxins (Basel) 2016; 9:toxins9010013. [PMID: 28036060 PMCID: PMC5307294 DOI: 10.3390/toxins9010013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/19/2016] [Accepted: 12/24/2016] [Indexed: 12/03/2022] Open
Abstract
The bloom-forming cyanobacteria, Cylindrospermopsis raciborskii, is a producer of the cytotoxic cylindrospermopsin (CYN). In this study, the growth, toxin yield, and expression of CYN biosynthesis genes of C. raciborskii were examined under varying phosphorus (P) concentrations. The results show the cell number at 0.00 and 0.01 mg·L−1 P was significantly lower than that at higher P concentrations (≥0.5 mg·L−1). The chlorophyll a content, filament length, heterocyst, and akinete numbers at P ≤ 0.05 mg·L−1 were also significantly reduced. The intracellular and extracellular CYN concentrations and the extracellular proportions increased during the culture period, and larger values were observed at higher P concentrations. Total CYN content reached 45.34–63.83 fg·cell−1 and extracellular CYN proportion reached 11.49%–20.44% at the stationary growth phase. A significantly positive correlation was observed between CYN production and cell growth rate. Three cyr genes were expressed constantly even at P-deficient conditions. The transcription of cyr genes at P-replete conditions or after P supplementation increased from 1.18-fold to 8.33-fold. In conclusion, C. raciborskii may rapidly reorganize metabolic processes as an adaptive response to environmental P fluctuations. CYN production and cyr gene expression were constitutive metabolic processes in toxic C. raciborskii.
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27
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Willis A, Chuang AW, Woodhouse JN, Neilan BA, Burford MA. Intraspecific variation in growth, morphology and toxin quotas for the cyanobacterium, Cylindrospermopsis raciborskii. Toxicon 2016; 119:307-10. [DOI: 10.1016/j.toxicon.2016.07.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/28/2016] [Accepted: 07/01/2016] [Indexed: 01/08/2023]
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28
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Burford MA, Beardall J, Willis A, Orr PT, Magalhaes VF, Rangel LM, Azevedo SMFOE, Neilan BA. Understanding the winning strategies used by the bloom-forming cyanobacterium Cylindrospermopsis raciborskii. HARMFUL ALGAE 2016; 54:44-53. [PMID: 28073481 DOI: 10.1016/j.hal.2015.10.012] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/14/2015] [Indexed: 05/06/2023]
Abstract
The cyanobacterium Cylindrospermopsis raciborskii is a widespread species increasingly being recorded in freshwater systems around the world. It is of particular concern because strains in some geographic areas are capable of producing toxins with implications for human and animal health. Studies of this species have increased rapidly in the last two decades, especially in the southern hemisphere where toxic strains are prevalent. A clearer picture is emerging of the strategies adopted by this species to bloom and out-compete other species. This species has a high level of flexibility with respect to light and nutrients, with higher temperatures and carbon dioxide also promoting growth. There are two types of toxins produced by C. raciborskii: cylindrospermopsins (CYNs) and saxitoxins (STXs). The toxins CYNs are constitutively produced irrespective of environmental conditions and the ecological or physiological role is unclear, while STXs appear to serve as protection against high salinity and/or water hardness. It is also apparent that strains of this species can vary substantially in their physiological responses to environmental conditions, including CYNs production, and this may explain discrepancies in findings from studies in different geographical areas. The combination of a flexible strategy with respect to environmental conditions, and variability in strain response makes it a challenging species to manage. Our ability to improve bloom prediction will rely on a more detailed understanding of the complex physiology of this species.
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Affiliation(s)
- Michele A Burford
- Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia.
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
| | - Anusuya Willis
- Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia.
| | - Philip T Orr
- Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia; School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
| | - Valeria F Magalhaes
- Institute of Biophysics Carlos Chagas Filho - CCS, Federal University of Rio, Rio de Janeiro 21941-902, Brazil.
| | - Luciana M Rangel
- Institute of Biophysics Carlos Chagas Filho - CCS, Federal University of Rio, Rio de Janeiro 21941-902, Brazil.
| | - Sandra M F O E Azevedo
- Institute of Biophysics Carlos Chagas Filho - CCS, Federal University of Rio, Rio de Janeiro 21941-902, Brazil.
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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29
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Cirés S, Ballot A. A review of the phylogeny, ecology and toxin production of bloom-forming Aphanizomenon spp. and related species within the Nostocales (cyanobacteria). HARMFUL ALGAE 2016; 54:21-43. [PMID: 28073477 DOI: 10.1016/j.hal.2015.09.007] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 09/22/2015] [Indexed: 05/16/2023]
Abstract
The traditional genus Aphanizomenon comprises a group of filamentous nitrogen-fixing cyanobacteria of which several memebers are able to develop blooms and to produce toxic metabolites (cyanotoxins), including hepatotoxins (microcystins), neurotoxins (anatoxins and saxitoxins) and cytotoxins (cylindrospermopsin). This genus, representing geographically widespread and extensively studied cyanobacteria, is in fact heterogeneous and composed of at least five phylogenetically distant groups (Aphanizomenon, Anabaena/Aphanizomenon like cluster A, Cuspidothrix, Sphaerospermopsis and Chrysosporum) whose taxonomy is still under revision. This review provides a thorough insight into the phylogeny, ecology, biogeography and toxicogenomics (cyr, sxt, and ana genes) of the five best documented "Aphanizomenon" species with special relevance for water risk assessment: Aphanizomenon flos-aquae, Aphanizomenon gracile, Cuspidothrix issatschenkoi, Sphaerospermopsis aphanizomenoides and Chrysosporum ovalisporum. Aph. flos-aquae, Aph. gracile and C. issatschenkoi have been reported from temperate areas only whereas S. aphanizomenoides shows the widest distribution from the tropics to temperate areas. Ch. ovalisporum is found in tropical, subtropical and Mediterranean areas. While all five species show moderate growth rates (0.1-0.4day-1) within a wide range of temperatures (15-30°C), Aph. gracile and A. flos-aquae can grow from around (or below) 10°C, whereas Ch. ovalisporum and S. aphanizomenoides are much better competitors at high temperatures over 30°C or even close to 35°C. A. gracile has been confirmed as the producer of saxitoxins and cylindrospermopsin, C. issatschenkoi of anatoxins and saxitoxins and Ch. ovalisporum of cylindrospermopsin. The suspected cylindrospermopsin or anatoxin-a production of A. flos-aquae or microcystin production of S. aphanizomenoides is still uncertain. This review includes a critical discussion on the the reliability of toxicity reports and on the invasive potential of "Aphanizomenon" species in a climate change scenario, together with derived knowledge gaps and research needs. As a whole, this work is intended to represent a key reference for scientists and water managers involved in the major challenges of identifying, preventing and mitigating toxic Aphanizomenon blooms.
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Affiliation(s)
- Samuel Cirés
- Departamento de Biología, Darwin, 2, Universidad Autónoma de Madrid, 28049 Madrid, Spain; College of Marine and Environmental Sciences, James Cook University, Townsville 4811, QLD, Australia.
| | - Andreas Ballot
- Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, 0349 Oslo, Norway
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30
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Gobler CJ, Burkholder JM, Davis TW, Harke MJ, Johengen T, Stow CA, Van de Waal DB. The dual role of nitrogen supply in controlling the growth and toxicity of cyanobacterial blooms. HARMFUL ALGAE 2016; 54:87-97. [PMID: 28073483 DOI: 10.1016/j.hal.2016.01.010] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/30/2016] [Indexed: 05/03/2023]
Abstract
Historically, phosphorus (P) has been considered the primary limiting nutrient for phytoplankton assemblages in freshwater ecosystems. This review, supported by new findings from Lake Erie, highlights recent molecular, laboratory, and field evidence that the growth and toxicity of some non-diazotrophic blooms of cyanobacteria can be controlled by nitrogen (N). Cyanobacteria such as Microcystis possess physiological adaptations that allow them to dominate low-P surface waters, and in temperate lakes, cyanobacterial densities can be controlled by N availability. Beyond total cyanobacterial biomass, N loading has been shown to selectively promote the abundance of Microcystis and Planktothrix strains capable of synthesizing microcystins over strains that do not possess this ability. Among strains of cyanobacteria capable of synthesizing the N-rich microcystins, cellular toxin quotas have been found to depend upon exogenous N supplies. Herein, multi-year observations from western Lake Erie are presented demonstrating that microcystin concentrations peak in parallel with inorganic N, but not orthophosphate, concentrations and are significantly lower (p<0.01) during years of reduced inorganic nitrogen loading and concentrations. Collectively, this information underscores the importance of N as well as P in controlling toxic cyanobacteria blooms. Furthermore, it supports the premise that management actions to reduce P in the absence of concurrent restrictions on N loading may not effectively control the growth and/or toxicity of non-diazotrophic toxic cyanobacteria such as the cosmopolitan, toxin-producing genus, Microcystis.
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Affiliation(s)
- Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Hwy, New York 11968, USA.
| | - JoAnn M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27606, USA
| | - Timothy W Davis
- NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI 48108, USA
| | - Matthew J Harke
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Hwy, New York 11968, USA
| | - Tom Johengen
- Cooperative Institute for Limnology and Ecosystems Research, University of Michigan, Ann Arbor, MI 48109, USA
| | - Craig A Stow
- NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI 48108, USA
| | - Dedmer B Van de Waal
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Post Office Box 50, Wageningen 6700 AB, The Netherlands
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31
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Pearson LA, Dittmann E, Mazmouz R, Ongley SE, D'Agostino PM, Neilan BA. The genetics, biosynthesis and regulation of toxic specialized metabolites of cyanobacteria. HARMFUL ALGAE 2016; 54:98-111. [PMID: 28073484 DOI: 10.1016/j.hal.2015.11.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/06/2015] [Indexed: 05/28/2023]
Abstract
The production of toxic metabolites by cyanobacterial blooms represents a significant threat to the health of humans and ecosystems worldwide. Here we summarize the current state of the knowledge regarding the genetics, biosynthesis and regulation of well-characterized cyanotoxins, including the microcystins, nodularin, cylindrospermopsin, saxitoxins and anatoxins, as well as the lesser-known marine toxins (e.g. lyngbyatoxin, aplysiatoxin, jamaicamides, barbamide, curacin, hectochlorin and apratoxins).
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Affiliation(s)
- Leanne A Pearson
- Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, NSW, Australia
| | - Elke Dittmann
- Institut für Biochemie und Biologie, Mikrobiologie, Universität Potsdam, Potsdam-Golm 14476, Germany
| | - Rabia Mazmouz
- Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, NSW, Australia
| | - Sarah E Ongley
- Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, NSW, Australia
| | - Paul M D'Agostino
- Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, NSW, Australia
| | - Brett A Neilan
- Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney 2052, NSW, Australia.
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Constitutive cylindrospermopsin pool size in Cylindrospermopsis raciborskii under different light and CO2 partial pressure conditions. Appl Environ Microbiol 2015; 81:3069-76. [PMID: 25724956 DOI: 10.1128/aem.03556-14] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/12/2015] [Indexed: 11/20/2022] Open
Abstract
Cylindrospermopsin (CYN) and 7-deoxy-cylindrospermopsin (dCYN) are potent hepatotoxic alkaloids produced by numerous species of cyanobacteria, including the freshwater Cylindrospermopsis raciborskii. C. raciborskii is an invasive cyanobacterium, and the study of how environmental parameters drive CYN production has received significant interest from water managers and health authorities. Light and CO2 affect cell growth and physiology in photoautotrophs, and these are potential regulators of cyanotoxin biosynthesis. In this study, we investigated how light and CO2 affect CYN and dCYN pool size as well as the expression of the key genes, cyrA and cyrK, involved in CYN biosynthesis in a toxic C. raciborskii strain. For cells growing at different light intensities (10 and 100 μmol photons m(-2) s(-1)), we observed that the rate of CYN pool size production (μCYN) was coupled to the cell division rate (μc) during batch culture. This indicated that CYN pool size under our experimental conditions is constant and cell quotas of CYN (QCYN) and dCYN (QdCYN) are fixed. Moreover, a lack of correlation between expression of cyrA and total CYN cell quotas (QCYNs) suggests that the CYN biosynthesis is regulated posttranscriptionally. Under elevated CO2 (1,300 ppm), we observed minor effects on QCYN and no effects on expression of cyrA and cyrK. We conclude that the CYN pool size is constitutive and not affected by light and CO2 conditions. Thus, C. raciborskii bloom toxicity is determined by the absolute abundance of C. raciborskii cells within the water column and the relative abundance of toxic and nontoxic strains.
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33
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Preußel K, Chorus I, Fastner J. Nitrogen limitation promotes accumulation and suppresses release of cylindrospermopsins in cells of Aphanizomenon sp. Toxins (Basel) 2014; 6:2932-47. [PMID: 25271784 PMCID: PMC4210877 DOI: 10.3390/toxins6102932] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/29/2014] [Accepted: 09/12/2014] [Indexed: 12/05/2022] Open
Abstract
As the biosynthesis of cylindrospermopsin (CYN) is assumed to depend on nitrogen availability, this study investigated the impact of nitrogen availability on intra- and extracellular CYN and deoxy-CYN (D-CYN) contents in three Aphanizomenon strains from temperate waters. Nitrogen deficient (−N) cultures showed a prolonged growth phase and intracellular toxin accumulation by a factor of 2–6. In contrast, cultures with additional nitrate supply (+N) did not accumulate CYN within the cells. Instead, the maximum conceivable CYN release estimated for dead cells (identified by SYTOX® Green staining) was much lower than the concentrations of dissolved CYN actually observed, suggesting these cultures actively release CYN from intact cells. Furthermore, we found remarkably altered proportions of CYN to D-CYN: as batch cultures grew, the proportion of D-CYN increased by up to 40% in +N medium, whereas D-CYN remained constant or decreased slightly in −N medium. Since +N cultures showed similar toxin patterns as −P cultures with increased extracellular CYNs and higher proportion of D-CYN we conclude that nitrogen limitation may affect the way the cells economize resources, especially the yield from phosphorus pools, and that this has an impact on CYN production and release. For water management, these result imply that nutrient availability not only determines the abundance of potentially CYN-producing cyanobacteria, but also the amount of extracellular CYNs (challenging drinking-water treatment) as well as the ratio of D-CYN to CYN (affecting toxicity).
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Affiliation(s)
- Karina Preußel
- Federal Environment Agency, Schichauweg 58, 12307 Berlin, Germany.
| | - Ingrid Chorus
- Federal Environment Agency, Schichauweg 58, 12307 Berlin, Germany.
| | - Jutta Fastner
- Federal Environment Agency, Schichauweg 58, 12307 Berlin, Germany.
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34
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Jiang Y, Xiao P, Yu G, Shao J, Liu D, Azevedo SMFO, Li R. Sporadic distribution and distinctive variations of cylindrospermopsin genes in cyanobacterial strains and environmental samples from Chinese freshwater bodies. Appl Environ Microbiol 2014; 80:5219-30. [PMID: 24928879 PMCID: PMC4136083 DOI: 10.1128/aem.00551-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 06/05/2014] [Indexed: 11/20/2022] Open
Abstract
Increasing reports of cylindrospermopsins (CYNs) in freshwater ecosystems have promoted the demand for identifying all of the potential CYN-producing cyanobacterial species. The present study explored the phylogenetic distribution and evolution of cyr genes in cyanobacterial strains and water samples from China. Four Cylindrospermopsis strains and two Raphidiopsis strains were confirmed to produce CYNs. Mutant cyrI and cyrK genes were observed in these strains. Cloned cyr gene sequences from eight water bodies were clustered with cyr genes from Cylindrospermopsis and Raphidiopsis (C/R group) in the phylogenetic trees with high similarities (99%). Four cyrI sequence types and three cyrJ sequence types were observed to have different sequence insertions and repeats. Phylogenetic analysis of the rpoC1 sequences of the C/R group revealed four conserved clades, namely, clade I, clade II, clade III, and clade V. High sequence similarities (>97%) in each clade and a divergent clade IV were observed. Therefore, CYN producers were sporadically distributed in congeneric and paraphyletic C/R group species in Chinese freshwater ecosystems. In the evolution of cyr genes, intragenomic translocations and intergenomic transfer between local Cylindrospermopsis and Raphidiopsis were emphasized and probably mediated by transposases. This research confirms the existence of CYN-producing Cylindrospermopsis in China and reveals the distinctive variations of cyr genes.
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Affiliation(s)
- Yongguang Jiang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, People's Republic of China University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Peng Xiao
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, People's Republic of China University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Gongliang Yu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Jihai Shao
- Resources and Environment College, Hunan Agricultural University, Changsha, People's Republic of China
| | - Deming Liu
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, People's Republic of China
| | - Sandra M F O Azevedo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Cidade Universitária, Rio de Janeiro, Brazil
| | - Renhui Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, People's Republic of China
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35
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Boopathi T, Ki JS. Impact of environmental factors on the regulation of cyanotoxin production. Toxins (Basel) 2014; 6:1951-78. [PMID: 24967641 PMCID: PMC4113735 DOI: 10.3390/toxins6071951] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/06/2014] [Accepted: 06/17/2014] [Indexed: 11/25/2022] Open
Abstract
Cyanobacteria are capable of thriving in almost all environments. Recent changes in climatic conditions due to increased human activities favor the occurrence and severity of harmful cyanobacterial bloom all over the world. Knowledge of the regulation of cyanotoxins by the various environmental factors is essential for effective management of toxic cyanobacterial bloom. In recent years, progress in the field of molecular mechanisms involved in cyanotoxin production has paved the way for assessing the role of various factors on the cyanotoxin production. In this review, we present an overview of the influence of various environmental factors on the production of major group of cyanotoxins, including microcystins, nodularin, cylindrospermopsin, anatoxins and saxitoxins.
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Affiliation(s)
| | - Jang-Seu Ki
- Department of Life Science, Sangmyung University, Seoul 110-743, Korea.
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36
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Stucken K, John U, Cembella A, Soto-Liebe K, Vásquez M. Impact of nitrogen sources on gene expression and toxin production in the diazotroph Cylindrospermopsis raciborskii CS-505 and non-diazotroph Raphidiopsis brookii D9. Toxins (Basel) 2014; 6:1896-915. [PMID: 24956074 PMCID: PMC4073136 DOI: 10.3390/toxins6061896] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 05/31/2014] [Accepted: 06/09/2014] [Indexed: 11/16/2022] Open
Abstract
Different environmental nitrogen sources play selective roles in the development of cyanobacterial blooms and noxious effects are often exacerbated when toxic cyanobacteria are dominant. Cylindrospermopsis raciborskii CS-505 (heterocystous, nitrogen fixing) and Raphidiopsis brookii D9 (non-N2 fixing) produce the nitrogenous toxins cylindrospermopsin (CYN) and paralytic shellfish toxins (PSTs), respectively. These toxin groups are biosynthesized constitutively by two independent putative gene clusters, whose flanking genes are target for nitrogen (N) regulation. It is not yet known how or if toxin biosynthetic genes are regulated, particularly by N-source dependency. Here we show that binding boxes for NtcA, the master regulator of N metabolism, are located within both gene clusters as potential regulators of toxin biosynthesis. Quantification of intra- and extracellular toxin content in cultures at early stages of growth under nitrate, ammonium, urea and N-free media showed that N-sources influence neither CYN nor PST production. However, CYN and PST profiles were altered under N-free medium resulting in a decrease in the predicted precursor toxins (doCYN and STX, respectively). Reduced STX amounts were also observed under growth in ammonium. Quantification of toxin biosynthesis and transport gene transcripts revealed a constitutive transcription under all tested N-sources. Our data support the hypothesis that PSTs and CYN are constitutive metabolites whose biosynthesis is correlated to cyanobacterial growth rather than directly to specific environmental conditions. Overall, the constant biosynthesis of toxins and expression of the putative toxin-biosynthesis genes supports the usage of qPCR probes in water quality monitoring of toxic cyanobacteria.
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Affiliation(s)
- Karina Stucken
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
| | - Uwe John
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
| | - Allan Cembella
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
| | - Katia Soto-Liebe
- Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile.
| | - Mónica Vásquez
- Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile.
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37
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Burford MA, Davis TW, Orr PT, Sinha R, Willis A, Neilan BA. Nutrient-related changes in the toxicity of field blooms of the cyanobacterium, Cylindrospermopsis raciborskii. FEMS Microbiol Ecol 2014; 89:135-48. [PMID: 24735048 DOI: 10.1111/1574-6941.12341] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/12/2014] [Accepted: 04/04/2014] [Indexed: 11/28/2022] Open
Abstract
Nutrients have the capacity to change cyanobacterial toxin loads via growth-related toxin production, or shifts in the dominance of toxic and nontoxic strains. This study examined the effect of nitrogen (N) and phosphorus on cell division and strain-related changes in production of the toxins, cylindrospermopsins (CYNs) by the cyanobacterium, Cylindrospermopsis raciborskii. Two short-term experiments were conducted with mixed phytoplankton populations dominated by C. raciborskii in a subtropical reservoir where treatments had nitrate (NO3 ), urea (U) and inorganic phosphorus (P) added alone or in combination. Cell division rates of C. raciborskii were only statistically higher than the control on day 5 when U and P were co-supplied. In contrast, cell quotas of CYNs (QCYNS ) increased significantly in treatments where P was supplied, irrespective of whether N was supplied, and this increase was not necessarily related to cell division rates. Increased QCYNS did correlate with an increase in the proportion of the cyrA toxin gene to 16S genes in the C. raciborskii-dominated cyanobacterial population. Therefore, changes in strain dominance are the most likely factor driving differences in toxin production between treatments. Our study has demonstrated differential effects of nutrients on cell division and strain dominance reflecting a C. raciborskii population with a range of strategies in response to environmental conditions.
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Affiliation(s)
- Michele A Burford
- Australian Rivers Institute, Griffith University, Nathan, Qld, Australia
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