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Arruda RS, Jacinavicius FR, Noyma NP, Drummond E, Barreto DA, da Silva LHS, Huszar VL, Pinto E, Lürling M, Marinho MM. Cyanopeptides occurrence and diversity in a Brazilian tropical reservoir: Exploring relationships with water quality. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 351:124051. [PMID: 38688388 DOI: 10.1016/j.envpol.2024.124051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/02/2024]
Abstract
Microcystins (MCs) are a class of toxic secondary metabolites produced by some cyanobacteria strains that endanger aquatic and terrestrial organisms in various freshwater systems. Although patterns in MC occurrence are being recognized, divergences in the global data still hamper our ability to predict the toxicity of cyanobacterial blooms. This study aimed (i) to determine the dynamics of MCs and other cyanopeptides in a tropical reservoir, (ii) to investigate the correlation between peptides and potential cyanotoxin producers (iii) identifying the possible abiotic factors that influence the peptides. We analyzed, monthly, eight MC variants (MC-RR, -LA, -LF, -LR, -LW, -YR, [D-Asp3]-RR and [D-Asp3]-LR) and other peptides in 47 water samples collected monthly, all season long, from two sampling sites in a tropical eutrophic freshwater reservoir, in southeastern Brazil. The cyanopeptides were assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The biomass of potential cyanobacterial producers and water quality variables were measured. MCs were detected in both sampling sites year-round; the total MC concentration varied from 0.21 to 4.04 μg L-1, and three MC variants were identified and quantified (MC-RR, [D-Asp3]-RR, -LR). Additionally, we identified 28 compounds belonging to three other cyanopeptide classes: aeruginosin, microginin, and cyanopeptolin. As potential MC producers, Microcystis spp. and Dolichospermum circinalis were dominant during the study, representing up to 75% of the total phytoplankton. Correlational and redundancy analysis suggested positive effects of dissolved oxygen, nitrate, and total phosphorus on MC and microginins concentration, while water temperature appeared to favor aeruginosins. A comparison between our results and historical data showed a reduction in total phosphorus and cyanobacteria, suggesting increased water quality in the reservoir. However, the current MC concentrations indicate a rise in cyanobacterial toxicity over the last eight years. Moreover, our study underscores the pressing need to explore cyanopeptides other than MCs in tropical aquatic systems.
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Affiliation(s)
- Renan Silva Arruda
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil.
| | - Fernanda Rios Jacinavicius
- Department of Clinical Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 580 - Bloco 17, São Paulo, SP, 05508-000, Brazil
| | - Natália Pessoa Noyma
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil
| | - Erick Drummond
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil
| | - Davi Almeida Barreto
- Laboratory of Phycology, National Museum, Federal University of Rio de Janeiro - UFRJ, Quinta da Boa Vista, São Cristóvão, CEP, 20940-040, Rio de Janeiro, RJ, Brazil
| | - Lúcia Helena Sampaio da Silva
- Laboratory of Phycology, National Museum, Federal University of Rio de Janeiro - UFRJ, Quinta da Boa Vista, São Cristóvão, CEP, 20940-040, Rio de Janeiro, RJ, Brazil
| | - Vera Lucia Huszar
- Laboratory of Phycology, National Museum, Federal University of Rio de Janeiro - UFRJ, Quinta da Boa Vista, São Cristóvão, CEP, 20940-040, Rio de Janeiro, RJ, Brazil
| | - Ernani Pinto
- Centre for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário, 303, São Dimas, Piracicaba, SP, 13416-000, Brazil
| | - Miquel Lürling
- Aquatic Ecology & Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700, AA, Wageningen, the Netherlands
| | - Marcelo Manzi Marinho
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, Rio de Janeiro, 20550-900, Brazil
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Ouyang X, Wahlsten M, Pollari M, Delbaje E, Jokela J, Fewer DP. Identification of a homoarginine biosynthetic gene from a microcystin biosynthetic pathway in Fischerella sp. PCC 9339. Toxicon 2024; 243:107733. [PMID: 38670499 DOI: 10.1016/j.toxicon.2024.107733] [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: 10/13/2023] [Revised: 03/02/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024]
Abstract
Microcystins (MCs) are a family of chemically diverse toxins produced by numerous distantly related cyanobacteria. They are potent inhibitors of eukaryotic protein phosphatases 1 and 2A and are responsible for the toxicosis and death of wild and domestic animals around the world. Microcystins are synthesized on large enzyme complexes comprised of peptide synthetases, polyketide synthases, and additional modifying enzymes. Bioinformatic analysis identified the presence of an additional uncharacterized enzyme in the microcystin (mcy) biosynthetic gene cluster in Fischerella sp. PCC 9339, which we named McyK, that lacked a clearly defined role in the biosynthesis of microcystin. Further bioinformatic analysis suggested that McyK belongs to the inosamine-phosphate amidinotransferase family and could be involved in synthesizing homo amino acids. Quadrupole time-of-flight tandem mass spectrometry (Q-TOFMS/MS) analysis confirmed that Fischerella sp. PCC 9339 produces MC-Leucine2-Homoarginine4(MC-LHar) and [Aspartic acid3]MC-Leucine2-Homoarginine4 ([Asp3]MC-LHar) as the dominant chemical variants. We hypothesized that the McyK enzyme might be involved in the production of microcystin variants containing homoarginine (Har) in the strain. Heterologous expression of a codon-optimized mcyK gene in Escherichia coli confirmed that McyK is responsible for the synthesis of L-Har. These results confirm the production of MC-LHar, a novel microcystin chemical variant [Asp3]MC-LHar, and a new microcystin biosynthetic enzyme involved in supply of the rare homo-amino acid Har to the microcystin biosynthetic pathway in Fischerella sp. PCC 9339. This study provides new insights into the logic underpinning the biosynthesis of microcystin chemical variants and broadens our knowledge of structural diversity of the microcystin family of toxins.
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Affiliation(s)
- Xiaodan Ouyang
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Matti Wahlsten
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - Maija Pollari
- Department of Agricultural Sciences, University of Helsinki, Latokartanonkaari 5, FI-00014, Helsinki, Finland
| | - Endrews Delbaje
- Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, 14040-903, Ribeirão Preto, Brazil
| | - Jouni Jokela
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland
| | - David P Fewer
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland.
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Piccini C, Martínez de la Escalera G, Segura AM, Croci C, Kruk C. The Microcystis-microbiome interactions: origins of the colonial lifestyle. FEMS Microbiol Ecol 2024; 100:fiae035. [PMID: 38499447 PMCID: PMC10996927 DOI: 10.1093/femsec/fiae035] [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: 01/04/2024] [Revised: 02/21/2024] [Accepted: 03/16/2024] [Indexed: 03/20/2024] Open
Abstract
Species of the Microcystis genus are the most common bloom-forming toxic cyanobacteria worldwide. They belong to a clade of unicellular cyanobacteria whose ability to reach high biomasses during blooms is linked to the formation of colonies. Colonial lifestyle provides several advantages under stressing conditions of light intensity, ultraviolet light, toxic substances and grazing. The progression from a single-celled organism to multicellularity in Microcystis has usually been interpreted as individual phenotypic responses of the cyanobacterial cells to the environment. Here, we synthesize current knowledge about Microcystis colonial lifestyle and its role in the organism ecology. We then briefly review the available information on Microcystis microbiome and propose that changes leading from single cells to colonies are the consequence of specific and tightly regulated signals between the cyanobacterium and its microbiome through a biofilm-like mechanism. The resulting colony is a multi-specific community of interdependent microorganisms.
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Affiliation(s)
- Claudia Piccini
- Departamento de Microbiología, Centro de Investigación en Ciencias Ambientales, Instituto de Investigaciones Biológicas Clemente Estable. Av. Italia 3318, Montevideo 11600, Uruguay
| | - Gabriela Martínez de la Escalera
- Departamento de Microbiología, Centro de Investigación en Ciencias Ambientales, Instituto de Investigaciones Biológicas Clemente Estable. Av. Italia 3318, Montevideo 11600, Uruguay
| | - Angel M Segura
- Modelización Estadística de Datos e Inteligencia Artificial, Centro Universitario Regional del Este, Universidad de la República. Ruta nacional Nº9 intersección con ruta Nº15, Uruguay
| | - Carolina Croci
- Departamento de Microbiología, Centro de Investigación en Ciencias Ambientales, Instituto de Investigaciones Biológicas Clemente Estable. Av. Italia 3318, Montevideo 11600, Uruguay
| | - Carla Kruk
- Modelización Estadística de Datos e Inteligencia Artificial, Centro Universitario Regional del Este, Universidad de la República. Ruta nacional Nº9 intersección con ruta Nº15, Uruguay
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales, Facultad de Ciencias, Universidad de la República. Iguá 4225, Montevideo 11400, Uruguay
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Romanis CS, Timms VJ, Nebauer DJ, Crosbie ND, Neilan BA. Microbiome analysis reveals Microcystis blooms endogenously seeded from benthos within wastewater maturation ponds. Appl Environ Microbiol 2024; 90:e0158523. [PMID: 38117057 PMCID: PMC10807444 DOI: 10.1128/aem.01585-23] [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: 09/14/2023] [Accepted: 10/27/2023] [Indexed: 12/21/2023] Open
Abstract
Toxigenic Microcystis blooms periodically disrupt the stabilization ponds of wastewater treatment plants (WWTPs). Dense proliferations of Microcystis cells within the surface waters (SWs) impede the water treatment process by reducing the treatment efficacy of the latent WWTP microbiome. Further, water quality is reduced when conventional treatment leads to Microcystis cell lysis and the release of intracellular microcystins into the water column. Recurrent seasonal Microcystis blooms cause significant financial burdens for the water industry and predicting their source is vital for bloom management strategies. We investigated the source of recurrent toxigenic Microcystis blooms at Australia's largest lagoon-based municipal WWTP in both sediment core (SC) and SW samples between 2018 and 2020. Bacterial community composition of the SC and SW samples according to 16S rRNA gene amplicon sequencing showed that Microcystis sp. was dominant within SW samples throughout the period and reached peak relative abundances (32%) during the summer. The same Microcystis Amplicon sequence variants were present within the SC and SW samples indicating a potential migratory population that transitions between the sediment water and SWs during bloom formation events. To investigate the potential of the sediment to act as a repository of viable Microcystis cells for recurrent bloom formation, a novel in-vitro bloom model was established featuring sediments and sterilized SW collected from the WWTP. Microcystin-producing Microcystis blooms were established through passive resuspension after 12 weeks of incubation. These results demonstrate the capacity of Microcystis to transition between the sediments and SWs in WWTPs, acting as a perennial inoculum for recurrent blooms.IMPORTANCECyanobacterial blooms are prevalent to wastewater treatment facilities owing to the stable, eutrophic conditions. Cyanobacterial proliferations can disrupt operational procedures through the blocking of filtration apparatus or altering the wastewater treatment plant (WWTP) microbiome, reducing treatment efficiency. Conventional wastewater treatment often results in the lysis of cyanobacterial cells and the release of intracellular toxins which pose a health risk to end users. This research identifies a potential seeding source of recurrent toxigenic cyanobacterial blooms within wastewater treatment facilities. Our results demonstrate the capacity of Microcystis to transition between the sediments and surface waters (SWs) of wastewater treatment ponds enabling water utilities to develop adequate monitoring and management strategies. Further, we developed a novel model to demonstrate benthic recruitment of toxigenic Microcystis under laboratory conditions facilitating future research into the genetic mechanisms behind bloom development.
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Affiliation(s)
- C. S. Romanis
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
| | - V. J. Timms
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
- ARC Centre of Excellence for Synthetic Biology, Callaghan, Australia
| | - D. J. Nebauer
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
| | | | - B. A. Neilan
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
- ARC Centre of Excellence for Synthetic Biology, Callaghan, Australia
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5
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Wang Z, Lei Y, Liu Q, Sun Y, Zhang L, Huang Y, Yang Z. Long-term acclimation to warming improves the adaptive ability of Microcystis aeruginosa to high temperature: Based on growth, photosynthetic activity, and microcystin production. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 338:122727. [PMID: 37838315 DOI: 10.1016/j.envpol.2023.122727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 09/21/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023]
Abstract
Gradually warming of water bodies caused by climate change is expected to intensify the expansion of Microcystis blooms causing a series of severe problems in waters. However, most predictions about global warming further promoting the dominance of Microcystis are dependent on the strains only experiencing short-term acclimation to high temperature. It still remains unknown whether long-term warming acclimation improves the adaptive ability of Microcystis to high temperature. The present study used Microcysits aeruginosa maintained at 25 °C, short- and long -term acclimated at 30 °C to explore the above knowledge gaps. The results showed that: (1) The growth rate of long-term warming acclimated M. aeruginosa was significantly enhanced, compared with those of low temperature cultured and short-term warming acclimated ones; (2) A faster decline rate of photosynthetic activity during growth phase and a higher ultimately stable photosynthetic activity during stationary phase of M. aeruginosa were caused by longer warming acclimation time; (3) high temperature reduced the microcystin production of long-term warming acclimated M. aeruginosa compared to that of low temperature cultured M. aeruginosa; (4) Warming acclimation time improved the driving effect of photosynthetic activity on the growth of M. aeruginosa but decreased the restriction ability of growth state to microcystin production of M. aeruginosa at high temperature; (5) Compared to low temperature cultured M. aeruginosa, high temperature improved the driving effect of photosynthetic activity on the growth of long-term warming acclimated M. aeruginosa, but decreased the sensitivity of photosynthetic activities to environmental resources and the regulative ability of microcystin production to photosynthetic activity. These findings indicated that long-term warming acclimation enhanced M. aeruginosa adaptive ability to high temperature and demonstrated the necessity of applying long-term warming acclimated strains in the future studies about the impact of global warming on cyanobacteria.
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Affiliation(s)
- Zeshuang Wang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China; National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, College of Life and Environmental Science, Wenzhou University, Wenzhou, 325035, China
| | - Yulu Lei
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Qi Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Yunfei Sun
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Lu Zhang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Yuan Huang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Zhou Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
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Chen Q, Wang Z, Wei H, Wang J, Zhou W, Zhou P, Li D. Environmental concentrations of anionic surfactants in lake surface microlayers enhance the toxicity of Microcystis blooms: Insight from photosynthesis, interspecies competition, and MC production. WATER RESEARCH 2023; 244:120430. [PMID: 37678037 DOI: 10.1016/j.watres.2023.120430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 09/09/2023]
Abstract
Anionic surfactants represented by linear alkylbenzene sulfonate (LAS) exhibit vertical heterogeneity of concentrations in aquatic environments owing to their amphiphilic structure. Field investigations showed that the concentration of anionic surfactants (mainly LAS) in the water surface microlayer (SML) of Lake Taihu reached 580 μg/L, higher than that in the lower layer. Floating Microcystis blooms overlap in space with the high concentration of anionic surfactants in SML. However, few studies have focused on the effects of anionic surfactants (e.g., LAS) on the interspecies competition between toxic and nontoxic Microcystis. In this study, coculture and monoculture experiments were conducted with both toxic and nontoxic Microcystis species to explore how the environmental concentration of LAS regulates the dominance of toxic Microcystis and toxicity from the perspective of photosynthesis, species dominance, and MC production. The results showed that LAS concentrations above 0.267 or 0.431 mg/L (depending on light conditions) selectively promoted the photosynthetic competitive advantage of toxic Microcystis, leading to its higher population proportion in the community. Additionally, LAS concentrations above 0.5 mg/L induced the synthesis and release of microcystins (MCs). The results of chlorophyll fluorescence analysis, electron microscopy and transcriptome sequencing suggested that compared with nontoxic Microcystis, toxic Microcystis can better resist LAS stress by dissipating excess light, maintaining an intact membrane structure and maintaining cellular homeostasis. Transcriptome sequencing revealed that the photosynthetic damage of nontoxic Microcystis might be attributed to the impacts of LAS on the absorption and assimilation of nitrogen, which finally resulted in the degradation of phycobilisomes. This study can provide novel insight for establishing standards and safety management of wastewater discharge.
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Affiliation(s)
- Qinyi Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Zhicong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China.
| | - Hui Wei
- Yulin Municipal Ecology and Environment Emergency and Technical Service Center, Yulin 537000, P.R. China
| | - Jinglong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Weicheng Zhou
- School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, P.R. China
| | - Panpan Zhou
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Dunhai Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P.R. China
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Bashir F, Bashir A, Bouaïcha N, Chen L, Codd GA, Neilan B, Xu WL, Ziko L, Rajput VD, Minkina T, Arruda RS, Ganai BA. Cyanotoxins, biosynthetic gene clusters, and factors modulating cyanotoxin biosynthesis. World J Microbiol Biotechnol 2023; 39:241. [PMID: 37394567 DOI: 10.1007/s11274-023-03652-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/17/2023] [Indexed: 07/04/2023]
Abstract
Cyanobacterial harmful algal blooms (CHABs) are a global environmental concern that encompasses public health issues, water availability, and water quality owing to the production of various secondary metabolites (SMs), including cyanotoxins in freshwater, brackish water, and marine ecosystems. The frequency, extent, magnitude, and duration of CHABs are increasing globally. Cyanobacterial species traits and changing environmental conditions, including anthropogenic pressure, eutrophication, and global climate change, together allow cyanobacteria to thrive. The cyanotoxins include a diverse range of low molecular weight compounds with varying biochemical properties and modes of action. With the application of modern molecular biology techniques, many important aspects of cyanobacteria are being elucidated, including aspects of their diversity, gene-environment interactions, and genes that express cyanotoxins. The toxicological, environmental, and economic impacts of CHABs strongly advocate the need for continuing, extensive efforts to monitor cyanobacterial growth and to understand the mechanisms regulating species composition and cyanotoxin biosynthesis. In this review, we critically examined the genomic organization of some cyanobacterial species that lead to the production of cyanotoxins and their characteristic properties discovered to date.
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Affiliation(s)
- Fahim Bashir
- Department of Environmental Science, University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India
| | - Arif Bashir
- Department of Clinical Biochemistry and Biotechnology, Government College for Women, Nawa-Kadal, Srinagar, Jammu & Kashmir, India
| | - Noureddine Bouaïcha
- Laboratory Ecology, Systematic, and Evolution, UMR 8079 Univ. Paris-Sud, CNRS, AgroParisTech, University Paris-Saclay, 91190, Gif-sur-Yvette, France.
| | - Liang Chen
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science (SEES), Yunnan University (YNU), 650500, Kunming, China.
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China.
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Faculty of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an, 710048, China.
| | - Geoffrey A Codd
- Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK
| | - Brett Neilan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Wen-Li Xu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China
| | - Laila Ziko
- School of Life and Medical Sciences, University of Hertfordshire Hosted By Global Academic Foundation, Cairo, Egypt
- Biology Department, School of Sciences and Engineering, The American University in Cairo, New Cairo, 11835, Egypt
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Renan Silva Arruda
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Bashir Ahmad Ganai
- Center of Research for Development (CORD), University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India.
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8
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Song Y, Li R, Song W, Tang Y, Sun S, Mao G. Microcystis spp. and phosphorus in aquatic environments: A comprehensive review on their physiological and ecological interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 878:163136. [PMID: 37001662 DOI: 10.1016/j.scitotenv.2023.163136] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/02/2023] [Accepted: 03/24/2023] [Indexed: 05/13/2023]
Abstract
Cyanobacterial blooms caused by eutrophication have become a major environmental problem in aquatic ecosystems worldwide over the last few decades. Phosphorus is a limiting nutrient that affects the growth of cyanobacteria and plays a role in dynamic changes in algal density and the formation of cyanobacterial blooms. Therefore, identifying the association between phosphorus sources and Microcystis, which is the most representative and harmful cyanobacteria, is essential for building an understanding of the ecological risks of cyanobacterial blooms. However, systematic reviews summarizing the relationships between Microcystis and phosphorus in aquatic environments are rare. Thus, this study provides a comprehensive overview of the physiological and ecological interactions between phosphorus sources and Microcystis in aquatic environments from the following perspectives: (i) the effects of phosphorus source and concentration on Microcystis growth, (ii) the impacts of phosphorus on the environmental behaviors of Microcystis, (iii) mechanisms of phosphorus-related metabolism in Microcystis, and (iv) role of Microcystis in the distribution of phosphorus sources within aquatic environments. In addition, relevant unsolved issues and essential future investigations (e.g., secondary ecological risks) have been highlighted and discussed. This review provides deeper insights into the relationship between phosphorus sources and Microcystis and can serve as a reference for the evaluation, monitoring, and effective control of cyanobacterial blooms.
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Affiliation(s)
- Yuhao Song
- School of Life Sciences, Qufu Normal University, Qufu 273165, China.
| | - Ruikai Li
- School of Life Sciences, Qufu Normal University, Qufu 273165, China
| | - Wenjia Song
- School of Life Sciences, Qufu Normal University, Qufu 273165, China
| | - Yulu Tang
- School of Life Sciences, Qufu Normal University, Qufu 273165, China
| | - Shuangyan Sun
- School of Life Sciences, Qufu Normal University, Qufu 273165, China
| | - Guannan Mao
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
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9
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Samuel SA, Chia MA, Yusufu WN, Dauda S, Japhet WS, Habila JD. Nitrogen forms and concentration influence the impact of titanium dioxide nanoparticles on the biomass and antioxidant enzyme activities of Microcystis aeruginosa. Arch Microbiol 2023; 205:177. [PMID: 37029289 DOI: 10.1007/s00203-023-03500-4] [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: 12/23/2022] [Revised: 03/18/2023] [Accepted: 03/22/2023] [Indexed: 04/09/2023]
Abstract
Nanoparticles (NPs) are becoming more widely produced, used, and released into the aquatic environment. In aquatic ecosystems, these NPs affect different populations of photosynthesizing organisms, such as cyanobacteria. This study aimed to evaluate the effects of titanium dioxide (TiO2) NPs (48 mg l-1) combined with low (0.04 mM) and high (9 mM) concentrations of urea and nitrate on Microcystis aeruginosa. Microcystins (MCs) production and release were monitored in the cyanobacterium. The results showed that high urea concentration (9 mM) combined with TiO2 NPs inhibited growth, pigment, and malondialdehyde (MDA) content by 82%, 63%, and 47%, respectively. The treatment also increased the reactive oxygen species (ROS) and glutathione S-transferase (GST) activity by 40.7% and 67.7%, respectively. Similarly, low nitrate (0.04 mM) combined with TiO2 NPs inhibited growth by 40.3% and GST activity by 36.3% but stimulated pigment production and ROS concentration in M. aeruginosa. These responses suggest that high urea combined with TiO2.NPs and high nitrate combined with TiO2 NPs induced oxidative stress in cyanobacteria. The peroxidase (POD) activity of M. aeruginosa decreased by 17.7% with increasing urea concentrations. Our findings suggest that TiO2 NPs combined with changing nutrient (urea and nitrate) concentrations may adversely affect cyanobacterial development and antioxidant defense enzymes.
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Affiliation(s)
| | | | - Waetsi Nya Yusufu
- Department of Botany, Ahmadu Bello University, Zaria, Nigeria
- Department of Biological Sciences, Taraba State University, Jalingo 14, Nigeria
| | - Suleiman Dauda
- Department of Botany, Ahmadu Bello University, Zaria, Nigeria
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10
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Guo Y, Zhao X, Yao Z, Qian Z, Wang Y, Xian Q. The effects of exogenous amino acids on production of microcystin variants in Microcystis aeruginosa. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 259:106525. [PMID: 37087861 DOI: 10.1016/j.aquatox.2023.106525] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/25/2023] [Accepted: 04/05/2023] [Indexed: 05/03/2023]
Abstract
Dissolved free amino acids are a significant component of dissolved organic nitrogen (DON) in natural waterbodies. The effects of four amino acids (glutamic acid, phenylalanine, leucine, and arginine) on the growth and microcystins (MCs) production of Microcystis aeruginosa were studied in batch culture. The profiles of five MCs variants and the expression levels of target genes involved in MCs biosynthesis and nitrogen metabolism were measured. When amino acids were used as the sole nitrogen source instead of nitrate at different levels (0.5, 2.0 and 8.0 mg/L based on N) in BG-11 medium, algal cell growth and intracellular MCs quotas were inhibited slightly by the treatments with glutamic acid and arginine. The treatments with phenylalanine and leucine, on the other hand, had a strong inhibitory effect on algal cell growth and MCs production. Moreover, the concentrations of Chlorophyll a, phycocyanin and allophycocyanin in cells cultured in glutamic acid, leucine and phenylalanine were lower than those in the control group with nitrate as nitrogen source. The existence of leucine or phenylalanine can lead to a significant increase in the relative abundance of MCs variants structured with the corresponding amino acids. The expression of microcystin-producing gene mcyD was downregulated while the gene pipX associated with nitrogen metabolism was upregulated during the cultivation of M. aeruginosa with amino acids as sole nitrogen source. M. aeruginosa undergoes significant alterations due to exogenous amino acids and exhibits advanced strategies for MCs production.
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Affiliation(s)
- Yaxin Guo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Xiating Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Zongcheng Yao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Zongyao Qian
- Guangxi Key Laboratory of Karst Ecological Processes and Services, Huanjiang Observation and Research Station for Karst Ecosystems, Chinese Academy of Sciences, Huanjiang 547100, China
| | - Yuting Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Qiming Xian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
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11
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Godoy RFB, Trevisan E, Battistelli AA, Crisigiovanni EL, do Nascimento EA, da Fonseca Machado AL. Does water temperature influence in microcystin production? A case study of Billings Reservoir, São Paulo, Brazil. JOURNAL OF CONTAMINANT HYDROLOGY 2023; 255:104164. [PMID: 36848739 DOI: 10.1016/j.jconhyd.2023.104164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 01/27/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
We investigated the relationship between some water quality parameters and microcystin, chlorophyll-a, and cyanobacteria in different conditions of water temperature. We also proposed to predict chlorophyll-a concentration in the Billings Reservoir using three machine learning techniques. Our results indicate that in the condition of higher water temperatures with high density of cyanobacteria, microcystin concentration can increase severely (>102 μg/L). Besides the magnitude observed in higher concentrations, in water temperatures above 25.3 °C (classified as high extreme event), higher frequencies of inadequate values of microcystin (87.5%), chlorophyll-a (70%), and cyanobacteria (82.5%) compared to cooler temperatures (<19.6 °C) were observed. The prediction of chlorophyll-a in Billings Reservoir presented good results (0.76 ≤ R2 ≤ 0.82; 0.17 ≤ RMSE≤0.20) using water temperature, total phosphorus, and cyanobacteria as predictors, with the best result using Support Vector Machine.
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Affiliation(s)
- Rodrigo Felipe Bedim Godoy
- Centre de recherche sur les interactions bassins versants-écosystèmes aquatiques (RIVE), Université du Québec à Trois-Rivières, Trois-Rivières, Quebec, Canada; Interuniversity Research Group in Limnology (GRIL), Université de Montréal, Montreal, Quebec, Canada.
| | - Elias Trevisan
- Instituto Federal do Paraná, Campus União da Vitória, União da Vitória, Paraná, Brazil
| | - André Aguiar Battistelli
- Department of Environmental Engineering, Midwestern State University (UNICENTRO), Maria Roza de Almeida Street, Irati, Paraná CEP 84505-677, Brazil
| | | | - Elynton Alves do Nascimento
- Department of Environmental Engineering, Midwestern State University (UNICENTRO), Maria Roza de Almeida Street, Irati, Paraná CEP 84505-677, Brazil.
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12
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Baer MM, Godwin CM, Johengen TH. The effect of single versus dual nutrient decreases on phytoplankton growth rates, community composition, and Microcystin concentration in the western basin of Lake Erie. HARMFUL ALGAE 2023; 123:102382. [PMID: 36894205 DOI: 10.1016/j.hal.2023.102382] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 01/06/2023] [Accepted: 01/08/2023] [Indexed: 06/18/2023]
Abstract
The primary management strategy for minimizing harmful algal blooms (HABs) in Lake Erie has been to reduce springtime loading of phosphorus (P) to the lake. However, some studies have shown that the growth rate and toxin content for the HABs-causing cyanobacterium Microcystis also respond to the availability of dissolved inorganic nitrogen (N). This evidence is based on both observational studies that correlate bloom development with changes in N forms and concentrations in the lake, and experiments in which P and/or N are added at concentrations in excess of those present in the lake. The goal of this study was to determine whether a combined decrease in N and P concentrations from ambient levels in Lake Erie could limit the development of HABs more than a reduction in P concentration only. To directly test the impact of P-only versus dual N and P concentration decreases on phytoplankton in the western basin of Lake Erie, we evaluated changes in growth rate, community composition, and microcystin (MC) concentration through eight bioassay experiments performed from June through October 2018, which encompassed the normal Lake Erie Microcystis-dominated HAB season. Our results showed that during the first five experiments covering June 25 to August 13, the P-only and the dual N and P decrease treatments had similar effects. However, when ambient N became scarce later in the season, the N and P decrease treatments resulted in negative growth rates for cyanobacteria, whereas -P only decreases did not. During low ambient N conditions, dual nutrient decreases lowered the prevalence of cyanobacteria among the total phytoplankton community and decreased microcystin concentrations. The results presented here complement previous experimental work on Lake Erie and suggest that dual nutrient control could be an effective management strategy to decrease microcystin production during the bloom and even possibly diminish or shorten the duration of the bloom based on creating nutrient limiting conditions sooner in the HAB growing season.
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Affiliation(s)
- Mikayla M Baer
- Cooperative Institute for Great Lakes Research, School for Environment and Sustainability, University of Michigan
| | - Casey M Godwin
- Cooperative Institute for Great Lakes Research, School for Environment and Sustainability, University of Michigan.
| | - Thomas H Johengen
- Cooperative Institute for Great Lakes Research, School for Environment and Sustainability, University of Michigan; Michigan Sea Grant, School for Environment and Sustainability, University of Michigan
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13
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Facey JA, Violi JP, King JJ, Sarowar C, Apte SC, Mitrovic SM. The Influence of Micronutrient Trace Metals on Microcystis aeruginosa Growth and Toxin Production. Toxins (Basel) 2022; 14:toxins14110812. [PMID: 36422986 PMCID: PMC9694995 DOI: 10.3390/toxins14110812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Microcystis aeruginosa is a widespread cyanobacteria capable of producing hepatotoxic microcystins. Understanding the environmental factors that influence its growth and toxin production is essential to managing the negative effects on freshwater systems. Some micronutrients are important cofactors in cyanobacterial proteins and can influence cyanobacterial growth when availability is limited. However, micronutrient requirements are often species specific, and can be influenced by substitution between metals or by luxury uptake. In this study, M. aeruginosa was grown in modified growth media that individually excluded some micronutrients (cobalt, copper, iron, manganese, molybdenum) to assess the effect on growth, toxin production, cell morphology and iron accumulation. M. aeruginosa growth was limited when iron, cobalt and manganese were excluded from the growth media, whereas the exclusion of copper and molybdenum had no effect on growth. Intracellular microcystin-LR concentrations were variable and were at times elevated in treatments undergoing growth limitation by cobalt. Intracellular iron was notably higher in treatments grown in cobalt-deplete media compared to other treatments possibly due to inhibition or competition for transporters, or due to irons role in detoxifying reactive oxygen species (ROS).
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Affiliation(s)
- Jordan A. Facey
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2000, Australia
- Correspondence:
| | - Jake P. Violi
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2000, Australia
| | - Josh J. King
- CSIRO Land and Water, Lucas Heights, Sydney, NSW 2234, Australia
| | - Chowdhury Sarowar
- Prince of Wales Clinical School, University of New South Wales, Kensington, NSW 2052, Australia
| | - Simon C. Apte
- CSIRO Land and Water, Lucas Heights, Sydney, NSW 2234, Australia
| | - Simon M. Mitrovic
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2000, Australia
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14
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Bachhar A, Jablonsky J. Entner-Doudoroff pathway in Synechocystis PCC 6803: Proposed regulatory roles and enzyme multifunctionalities. Front Microbiol 2022; 13:967545. [PMID: 36051759 PMCID: PMC9424857 DOI: 10.3389/fmicb.2022.967545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
The Entner-Doudoroff pathway (ED-P) was established in 2016 as the fourth glycolytic pathway in Synechocystis sp. PCC 6803. ED-P consists of two reactions, the first catalyzed by 6-phosphogluconate dehydratase (EDD), the second by keto3-deoxygluconate-6-phosphate aldolase/4-hydroxy-2-oxoglutarate aldolase (EDA). ED-P was previously concluded to be a widespread (∼92%) pathway among cyanobacteria, but current bioinformatic analysis estimated the occurrence of ED-P to be either scarce (∼1%) or uncommon (∼47%), depending if dihydroxy-acid dehydratase (ilvD) also functions as EDD (currently assumed). Thus, the biochemical characterization of ilvD is a task pending to resolve this uncertainty. Next, we have provided new insights into several single and double glycolytic mutants based on kinetic model of central carbon metabolism of Synechocystis. The model predicted that silencing 6-phosphogluconate dehydrogenase (gnd) could be coupled with ∼90% down-regulation of G6P-dehydrogenase, also limiting the metabolic flux via ED-P. Furthermore, our metabolic flux estimation implied that growth impairment linked to silenced EDA under mixotrophic conditions is not caused by diminished carbon flux via ED-P but rather by a missing mechanism related to the role of EDA in metabolism. We proposed two possible, mutually non-exclusive explanations: (i) Δeda leads to disrupted carbon catabolite repression, regulated by 2-keto3-deoxygluconate-6-phosphate (ED-P intermediate), and (ii) EDA catalyzes the interconversion between glyoxylate and 4-hydroxy-2-oxoglutarate + pyruvate in the proximity of TCA cycle, possibly effecting the levels of 2-oxoglutarate under Δeda. We have also proposed a new pathway from EDA toward proline, which could explain the proline accumulation under Δeda. In addition, the presented in silico method provides an alternative to 13C metabolic flux analysis for marginal metabolic pathways around/below the threshold of ultrasensitive LC-MS. Finally, our in silico analysis provided alternative explanations for the role of ED-P in Synechocystis while identifying some severe uncertainties.
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15
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Jalili F, Moradinejad S, Zamyadi A, Dorner S, Sauvé S, Prévost M. Evidence-Based Framework to Manage Cyanobacteria and Cyanotoxins in Water and Sludge from Drinking Water Treatment Plants. Toxins (Basel) 2022; 14:toxins14060410. [PMID: 35737071 PMCID: PMC9228313 DOI: 10.3390/toxins14060410] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/12/2022] [Accepted: 06/13/2022] [Indexed: 02/07/2023] Open
Abstract
Freshwater bodies and, consequently, drinking water treatment plants (DWTPs) sources are increasingly facing toxic cyanobacterial blooms. Even though conventional treatment processes including coagulation, flocculation, sedimentation, and filtration can control cyanobacteria and cell-bound cyanotoxins, these processes may encounter challenges such as inefficient removal of dissolved metabolites and cyanobacterial cell breakthrough. Furthermore, conventional treatment processes may lead to the accumulation of cyanobacteria cells and cyanotoxins in sludge. Pre-oxidation can enhance coagulation efficiency as it provides the first barrier against cyanobacteria and cyanotoxins and it decreases cell accumulation in DWTP sludge. This critical review aims to: (i) evaluate the state of the science of cyanobacteria and cyanotoxin management throughout DWTPs, as well as their associated sludge, and (ii) develop a decision framework to manage cyanobacteria and cyanotoxins in DWTPs and sludge. The review identified that lab-cultured-based pre-oxidation studies may not represent the real bloom pre-oxidation efficacy. Moreover, the application of a common exposure unit CT (residual concentration × contact time) provides a proper understanding of cyanobacteria pre-oxidation efficiency. Recently, reported challenges on cyanobacterial survival and growth in sludge alongside the cell lysis and cyanotoxin release raised health and technical concerns with regards to sludge storage and sludge supernatant recycling to the head of DWTPs. According to the review, oxidation has not been identified as a feasible option to handle cyanobacterial-laden sludge due to low cell and cyanotoxin removal efficacy. Based on the reviewed literature, a decision framework is proposed to manage cyanobacteria and cyanotoxins and their associated sludge in DWTPs.
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Affiliation(s)
- Farhad Jalili
- Department of Civil, Mineral and Mining Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (F.J.); (S.D.); (M.P.)
| | - Saber Moradinejad
- Department of Civil, Mineral and Mining Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (F.J.); (S.D.); (M.P.)
- Correspondence:
| | - Arash Zamyadi
- Faculty of Engineering and Information Technology, University of Melbourne, Melbourne, VIC 3010, Australia;
| | - Sarah Dorner
- Department of Civil, Mineral and Mining Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (F.J.); (S.D.); (M.P.)
| | - Sébastien Sauvé
- Department of Chemistry, University of Montréal, Montréal, QC H3C 3J7, Canada;
| | - Michèle Prévost
- Department of Civil, Mineral and Mining Engineering, Polytechnique Montréal, Montréal, QC H3C 3A7, Canada; (F.J.); (S.D.); (M.P.)
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16
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Hellweger FL, Martin RM, Eigemann F, Smith DJ, Dick GJ, Wilhelm SW. Models predict planned phosphorus load reduction will make Lake Erie more toxic. Science 2022; 376:1001-1005. [PMID: 35617400 DOI: 10.1126/science.abm6791] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Harmful cyanobacteria are a global environmental problem, yet we lack actionable understanding of toxigenic versus nontoxigenic strain ecology and toxin production. We performed a large-scale meta-analysis including 103 papers and used it to develop a mechanistic, agent-based model of Microcystis growth and microcystin production. Simulations for Lake Erie suggest that the observed toxigenic-to-nontoxigenic strain succession during the 2014 Toledo drinking water crisis was controlled by different cellular oxidative stress mitigation strategies (protection by microcystin versus degradation by enzymes) and the different susceptibility of those mechanisms to nitrogen limitation. This model, as well as a simpler empirical one, predicts that the planned phosphorus load reduction will lower biomass but make nitrogen and light more available, which will increase toxin production, favor toxigenic cells, and increase toxin concentrations.
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Affiliation(s)
- Ferdi L Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - Robbie M Martin
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Falk Eigemann
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - Derek J Smith
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA.,Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, MI, USA
| | - Steven W Wilhelm
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
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17
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Dulić T, Svirčev Z, Palanački Malešević T, Faassen EJ, Savela H, Hao Q, Meriluoto J. Assessment of Common Cyanotoxins in Cyanobacteria of Biological Loess Crusts. Toxins (Basel) 2022; 14:toxins14030215. [PMID: 35324712 PMCID: PMC8953721 DOI: 10.3390/toxins14030215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/27/2022] [Accepted: 03/11/2022] [Indexed: 12/23/2022] Open
Abstract
Cyanotoxins are a diverse group of bioactive compounds produced by cyanobacteria that have adverse effects on human and animal health. While the phenomenon of cyanotoxin production in aquatic environments is well studied, research on cyanotoxins in terrestrial environments, where cyanobacteria abundantly occur in biocrusts, is still in its infancy. Here, we investigated the potential cyanotoxin production in cyanobacteria-dominated biological loess crusts (BLCs) from three different regions (China, Iran, and Serbia) and in cyanobacterial cultures isolated from the BLCs. The presence of cyanotoxins microcystins, cylindrospermopsin, saxitoxins, and β-N-methylamino-L-alanine was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, while the presence of cyanotoxin-encoding genes (mcyE, cyrJ, sxtA, sxtG, sxtS, and anaC) was investigated by polymerase chain reaction (PCR) method. We could not detect any of the targeted cyanotoxins in the biocrusts or the cyanobacterial cultures, nor could we amplify any cyanotoxin-encoding genes in the cyanobacterial strains. The results are discussed in terms of the biological role of cyanotoxins, the application of cyanobacteria in land restoration programs, and the use of cyanotoxins as biosignatures of cyanobacterial populations in loess research. The article highlights the need to extend the field of research on cyanobacteria and cyanotoxin production to terrestrial environments.
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Affiliation(s)
- Tamara Dulić
- Department of Biochemistry, Faculty of Sciences and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland; (Z.S.); (J.M.)
- Correspondence:
| | - Zorica Svirčev
- Department of Biochemistry, Faculty of Sciences and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland; (Z.S.); (J.M.)
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia;
| | - Tamara Palanački Malešević
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia;
| | - Elisabeth J. Faassen
- Wageningen Food Safety Research, Wageningen University and Research, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands;
- Aquatic Ecology and Water Quality Management, Wageningen University and Research, Droevendaalsesteeg 3a, 6708 PB Wageningen, The Netherlands
| | - Henna Savela
- Department of Life Technologies, Faculty of Technology, University of Turku, Kiinamyllynkatu 10, 20014 Turku, Finland;
| | - Qingzhen Hao
- Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19, Beitucheng Western Road, Beijing 100029, China;
| | - Jussi Meriluoto
- Department of Biochemistry, Faculty of Sciences and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland; (Z.S.); (J.M.)
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia;
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18
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Oxidation to Control Cyanobacteria and Cyanotoxins in Drinking Water Treatment Plants: Challenges at the Laboratory and Full-Scale Plants. WATER 2022. [DOI: 10.3390/w14040537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The impact of oxidation on mitigation of cyanobacteria and cyanotoxins in drinking water treatment sludge was investigated at the laboratory and treatment plant scales. Two common oxidants, KMnO4 (5 and 10 mg/L) and H2O2 (10 and 20 mg/L) were applied under controlled steady-state conditions. Non-oxidized and oxidized sludge was left to stagnate in the dark for 7 to 38 days. Controlled laboratory trials show that KMnO4 and H2O2 decreased cell counts up to 62% and 77%, respectively. The maximum total MC level reduction achieved after oxidation was 41% and 98% using 20 mg/L H2O2 and 10 mg/L KMnO4, respectively. Stagnation caused cell growth up to 2.6-fold in 8 out of 22 oxidized samples. Microcystin (MC) producer orders as Chroococcales and Synechococcales were persistent while Nostocales was sensitive to combined oxidation and stagnation stresses. In parallel, two on-site shock oxidation treatments were performed in the DWTP’s sludge holding tank using 10 mg/L KMnO4. On-site shock oxidation decreased taxonomic cell counts by up to 43% within 24 h. Stagnation preceded by on-site shock oxidation could increase total cell counts by up to 55% as compared to oxidation alone. The increase of cell counts and mcyD gene copy numbers during stagnation revealed the impact of oxidation/stagnation on cyanobacterial cell growth. These findings show the limitations of sludge oxidation as a strategy to manage cyanobacteria and cyanotoxins in sludge and suggest that alternative approaches to prevent the accumulation and mitigation of cyanobacteria in sludge should be considered.
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19
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Feist SM, Lance RF. Genetic detection of freshwater harmful algal blooms: A review focused on the use of environmental DNA (eDNA) in Microcystis aeruginosa and Prymnesium parvum. HARMFUL ALGAE 2021; 110:102124. [PMID: 34887004 DOI: 10.1016/j.hal.2021.102124] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
Recurrence and severity of harmful algal blooms (HABs) are increasing due to a number of factors, including human practices and climate change. Sensitive and robust methods that allow for early and expedited HAB detection across large landscape scales are needed. Among the suite of HAB detection tools available, a powerful option exists in genetics-based approaches utilizing environmental sampling, also termed environmental DNA (eDNA). Here we provide a detailed methodological review of three HAB eDNA approaches (quantitative PCR, high throughput sequencing, and isothermal amplification). We then summarize and synthesize recently published eDNA applications covering a variety of HAB surveillance and research objectives, all with a specific emphasis in the detection of two widely problematic freshwater species, Microcystis aeruginosa and Prymnesium parvum. In our summary and conclusion we build on this literature by discussing ways in which eDNA methods could be advanced to improve HAB detection. We also discuss ways in which eDNA data could be used to potentially provide novel insight into the ecology, mitigation, and prediction of HABs.
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Affiliation(s)
- Sheena M Feist
- Environmental Lab, United States Army Corps of Engineers Research and Development Center, Vicksburg, MS, 39180, United States.
| | - Richard F Lance
- Environmental Lab, United States Army Corps of Engineers Research and Development Center, Vicksburg, MS, 39180, United States
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20
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Cyanobacteria and Cyanotoxins in a Changing Environment: Concepts, Controversies, Challenges. WATER 2021. [DOI: 10.3390/w13182463] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Concern is widely being published that the occurrence of toxic cyanobacteria is increasing in consequence of climate change and eutrophication, substantially threatening human health. Here, we review evidence and pertinent publications to explore in which types of waterbodies climate change is likely to exacerbate cyanobacterial blooms; whether controlling blooms and toxin concentrations requires a balanced approach of reducing not only the concentrations of phosphorus (P) but also those of nitrogen (N); how trophic and climatic changes affect health risks caused by toxic cyanobacteria. We propose the following for further discussion: (i) Climate change is likely to promote blooms in some waterbodies—not in those with low concentrations of P or N stringently limiting biomass, and more so in shallow than in stratified waterbodies. Particularly in the latter, it can work both ways—rendering conditions for cyanobacterial proliferation more favourable or less favourable. (ii) While N emissions to the environment need to be reduced for a number of reasons, controlling blooms can definitely be successful by reducing only P, provided concentrations of P can be brought down to levels sufficiently low to stringently limit biomass. Not the N:P ratio, but the absolute concentration of the limiting nutrient determines the maximum possible biomass of phytoplankton and thus of cyanobacteria. The absolute concentrations of N or P show which of the two nutrients is currently limiting biomass. N can be the nutrient of choice to reduce if achieving sufficiently low concentrations has chances of success. (iii) Where trophic and climate change cause longer, stronger and more frequent blooms, they increase risks of exposure, and health risks depend on the amount by which concentrations exceed those of current WHO cyanotoxin guideline values for the respective exposure situation. Where trophic change reduces phytoplankton biomass in the epilimnion, thus increasing transparency, cyanobacterial species composition may shift to those that reside on benthic surfaces or in the metalimnion, changing risks of exposure. We conclude that studying how environmental changes affect the genotype composition of cyanobacterial populations is a relatively new and exciting research field, holding promises for understanding the biological function of the wide range of metabolites found in cyanobacteria, of which only a small fraction is toxic to humans. Overall, management needs case-by-case assessments focusing on the impacts of environmental change on the respective waterbody, rather than generalisations.
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21
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Changes in Growth, Photosynthesis Performance, Pigments, and Toxin Contents of Bloom-Forming Cyanobacteria after Exposure to Macroalgal Allelochemicals. Toxins (Basel) 2021; 13:toxins13080589. [PMID: 34437460 PMCID: PMC8402365 DOI: 10.3390/toxins13080589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/10/2021] [Accepted: 08/20/2021] [Indexed: 11/17/2022] Open
Abstract
Macroalgae can directly restrict the growth of various phytoplankton species by releasing allelopathic compounds; therefore, considerable attention should be paid to the allelopathic potential of these organisms against harmful and bloom-forming cyanobacteria. The main aim of this study was to demonstrate for the first time the allelopathic activity of Ulva intestinalis on the growth, the fluorescence parameters: the maximum PSII quantum efficiency (Fv/Fm) and the effective quantum yield of PSII photochemistry (ΦPSII), the chlorophyll a (Chl a) and carotenoid (Car) content, and the microcystin-LR (MC-LR) and phenol content of three bloom-forming cyanobacteria, Aphanizomenon sp., Nodularia spumigena, and Nostoc sp. We found both negative and positive allelopathic effects of U. intestinalis on tested cyanobacteria. The study clearly showed that the addition of the filtrate of U. intestinalis significantly inhibited growth, decreased pigment content and Fv/Fm and ΦPSII values of N. spumigena and Nostoc sp., and stimulated Aphanizomenon sp. The addition of different concentrations of aqueous extract also stimulated the cyanobacterial growth. It was also shown that the addition of extract obtained from U. intestinalis caused a significant decrease in the MC-LR content in Nostoc sp. cells. Moreover, it the phenol content in N. spumigena cells was increased. On the other hand, the cell-specific phenol content for Aphanizomenon sp. decreased due to the addition of the filtrate. In this work, we demonstrated that the allelopathic effect of U. intestinalis depends on the target species’ identity as well as the type of allelopathic method used. The study of the allelopathic Baltic macroalgae may help to identify their possible role as a significant biological factor influencing harmful cyanobacterial blooms in brackish ecosystems.
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Wood SA, Puddick J, Hawes I, Steiner K, Dietrich DR, Hamilton DP. Variability in microcystin quotas during a Microcystis bloom in a eutrophic lake. PLoS One 2021; 16:e0254967. [PMID: 34288957 PMCID: PMC8294494 DOI: 10.1371/journal.pone.0254967] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 07/08/2021] [Indexed: 11/18/2022] Open
Abstract
Microcystis is a bloom-forming genus of cyanobacteria with some genotypes that produce highly toxic microcystin hepatotoxins. In waterbodies where biological and physical factors are relatively homogenous, toxin quotas (the average amount of toxin per cell), at a single point in time, are expected to be relatively constant. In this study we challenged this assumption by investigating the spatial distribution of microcystin quotas at a single point in time on two separate occasions in a lake with a major Microcystis bloom. Microcystis cell concentrations varied widely across the lake on both sampling occasions (730- and 137-fold) together with microcystin quotas (148- and 362-fold). Cell concentrations and microcystin quotas were strongly positively correlated (R2 = 0.89, P < 0.001, n = 28; R2 = 0.67, P < 0.001, n = 25). Analysis of Microcystis strains using high-throughput sequencing of the 16S-23S rRNA intergenic spacer region showed no relationship between microcystin quota and the relative abundance of specific sequences. Collectively, the results of this study indicate an association between microcystin production and cell density that magnifies the potential for bloom toxicity at elevated cell concentrations.
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Affiliation(s)
| | | | - Ian Hawes
- Department of Biological Sciences, University of Waikato, Hamilton, New Zealand
| | | | | | - David P. Hamilton
- Australian Rivers Institute, Griffith University, Brisbane, Australia
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Zhu R, Wang H, Shen H, Deng X, Chen J. The dynamics and release characteristics of microcystins in the plateau Lake Erhai, Southwest China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:23473-23481. [PMID: 33452641 DOI: 10.1007/s11356-020-12312-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Microcystins (MCs) have seriously polluted drinking water supplies and have caused great harm to aquatic organisms and humans. Understanding the dynamics of MC concentrations and its influencing factors is necessary for drinking water safety. Many previous studies on MC pollution focused on intracellular MCs rather than on extracellular MCs, which are more difficult to remove by water treatment. So far, the release characteristics of MCs and the relationships between intracellular and extracellular MCs are still unclear. To explore these questions, a survey was conducted at 18 sites across Lake Erhai from May 2014 to April 2015 as in Lake Erhai the frequency and coverage area of cyanobacterial blooms have been increasing. Variation of extracellular MCs lagged behind that of intracellular MCs. The highest value of intracellular MCs was 1.07 μg L-1 in October 2014 and the highest extracellular MC concentration was 0.035 μg L-1 in November 2014. Intracellular MCs were positively influenced by MC-producing cyanobacterial biomass, water temperature (WT), pH, and conductivity (Cond). The extracellular MCs showed little correlation with cyanobacterial abundances and intracellular MC concentrations, but showed significant negative correlations with WT, pH, and Cond. These results indicated that high biomass and high intracellular MC concentrations did not quickly lead to large releases of MCs, and that when cyanobacterial cells died and blooms disappeared, MCs were intensively released into the water, posing the greatest threat to drinking water supply.
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Affiliation(s)
- Rong Zhu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
- Marine Fisheries Research Institute of Zhejiang, Zhoushan, 316021, People's Republic of China
| | - Huan Wang
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Hong Shen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Xuwei Deng
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China
| | - Jun Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, People's Republic of China.
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Xu S, Liu Y, Zhang J, Gao B. Proteomic mechanisms for the combined stimulatory effects of glyphosate and antibiotic contaminants on Microcystis aeruginosa. CHEMOSPHERE 2021; 267:129244. [PMID: 33321278 DOI: 10.1016/j.chemosphere.2020.129244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/04/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
A single exposure to glyphosate or antibiotic may facilitate cyanobacterial growth at currently reported concentrations due to hormesis. However, the influence of these contaminants on cyanobacteria under combined exposure conditions has not been reported. In this study, proteomic mechanisms for the combined effects of glyphosate and a quaternary antibiotic mixture of amoxicillin, sulfamethoxazole, tetracycline, and ciprofloxacin in a dominant bloom-forming cyanobacterium (Microcystis aeruginosa) were investigated and compared with those for single exposure to glyphosate. The growth rate of M. aeruginosa, photosynthetic activity indicated by Fv/Fm, and microcystin production ability showed a typical U-shaped hormetic dose-response to glyphosate exposure. Upregulated proteins related to photosynthesis and biosynthesis, as well as increased photosynthetic activity, were responsible for the stimulated growth induced by 0.1-5 μg/L glyphosate, while the upregulation of mcyB protein contributed to increased microcystin synthesis in glyphosate-treated cells. The presence of 0.04-0.2 μg/L mixed antibiotics significantly (p < 0.05) enhanced the stimulation effects of glyphosate. Combined exposure to glyphosate and mixed antibiotics promoted microcystin synthesis through the upregulation of six microcystin synthesis regulatory proteins (mcyC, mcyF, mcyG, mcyI, MAE_56520, and ntcA) and stimulated cyanobacterial growth through the upregulation of proteins involved in photosynthesis, cell division, carbon fixation, pentose phosphate, translation, and chlorophyll synthesis. Combined exposure to glyphosate and antibiotic contaminants promoted cyanobacterial growth at no-effect concentrations of single exposure (0.04 μg/L for mixed antibiotics; 0.05, 10 and 100 μg/L for glyphosate), suggesting an increased threat from combined contamination to aquatic ecosystems through promoting the formation of cyanobacterial bloom.
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Affiliation(s)
- Sijia Xu
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, PR China
| | - Ying Liu
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, PR China.
| | - Jian Zhang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, PR China
| | - Baoyu Gao
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, PR China
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Zupančič M, Kogovšek P, Šter T, Remec Rekar Š, Cerasino L, Baebler Š, Krivograd Klemenčič A, Eleršek T. Potentially Toxic Planktic and Benthic Cyanobacteria in Slovenian Freshwater Bodies: Detection by Quantitative PCR. Toxins (Basel) 2021; 13:toxins13020133. [PMID: 33670338 PMCID: PMC7917684 DOI: 10.3390/toxins13020133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/03/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
Due to increased frequency of cyanobacterial blooms and emerging evidence of cyanotoxicity in biofilm, reliable methods for early cyanotoxin threat detection are of major importance for protection of human, animal and environmental health. To complement the current methods of risk assessment, this study aimed to evaluate selected qPCR assays for detection of potentially toxic cyanobacteria in environmental samples. In the course of one year, 25 plankton and 23 biofilm samples were collected from 15 water bodies in Slovenia. Three different analyses were performed and compared to each other; qPCR targeting mcyE, cyrJ and sxtA genes involved in cyanotoxin production, LC-MS/MS quantifying microcystin, cylindrospermopsin and saxitoxin concentration, and microscopic analyses identifying potentially toxic cyanobacterial taxa. qPCR analyses detected potentially toxic Microcystis in 10 lake plankton samples, and potentially toxic Planktothrix cells in 12 lake plankton and one lake biofilm sample. A positive correlation was observed between numbers of mcyE gene copies and microcystin concentrations. Potential cylindrospermopsin- and saxitoxin-producers were detected in three and seven lake biofilm samples, respectively. The study demonstrated a potential for cyanotoxin production that was left undetected by traditional methods in both plankton and biofilm samples. Thus, the qPCR method could be useful in regular monitoring of water bodies to improve risk assessment and enable timely measures.
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Affiliation(s)
- Maša Zupančič
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, 1000 Ljubljana, Slovenia;
- Jozef Stefan International Postgraduate School, 1000 Ljubljana, Slovenia
- Correspondence:
| | - Polona Kogovšek
- Department of Biotechnology and Systems Biology, National Institute of Biology, 1000 Ljubljana, Slovenia; (P.K.); (Š.B.)
| | - Tadeja Šter
- Slovenian Environment Agency, 1000 Ljubljana, Slovenia; (T.Š.); (Š.R.R.); (A.K.K.)
| | - Špela Remec Rekar
- Slovenian Environment Agency, 1000 Ljubljana, Slovenia; (T.Š.); (Š.R.R.); (A.K.K.)
| | - Leonardo Cerasino
- Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all’Adige, Italy;
| | - Špela Baebler
- Department of Biotechnology and Systems Biology, National Institute of Biology, 1000 Ljubljana, Slovenia; (P.K.); (Š.B.)
| | | | - Tina Eleršek
- Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, 1000 Ljubljana, Slovenia;
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26
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Martin RM, Moniruzzaman M, Stark GF, Gann ER, Derminio DS, Wei B, Hellweger FL, Pinto A, Boyer GL, Wilhelm SW. Episodic Decrease in Temperature Increases mcy Gene Transcription and Cellular Microcystin in Continuous Cultures of Microcystis aeruginosa PCC 7806. Front Microbiol 2020; 11:601864. [PMID: 33343544 PMCID: PMC7744600 DOI: 10.3389/fmicb.2020.601864] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/12/2020] [Indexed: 11/26/2022] Open
Abstract
Microcystins produced during harmful cyanobacterial blooms are a public health concern. Although patterns are emerging, the environmental cues that stimulate production of microcystin remain confusing, hindering our ability to predict fluctuations in bloom toxicity. In earlier work, growth at cool temperatures relative to optimum (18°C vs. 26°C) was confirmed to increase microcystin quota in batch cultures of Microcystis aeruginosa NIES-843. Here, we tested this response in M. aeruginosa PCC 7806 using continuous cultures to examine temporal dynamics and using RNA-sequencing to investigate the physiological nature of the response. A temperature reduction from 26 to 19°C increased microcystin quota ∼2-fold, from an average of ∼464 ag μm–3 cell volume to ∼891 ag μm–3 over a 7–9 d period. Reverting the temperature to 26°C returned the cellular microcystin quota to ∼489 ag μm–3. Long periods (31–42 d) at 19°C did not increase or decrease microcystin quota beyond that observed at 7–9 d. Nitrogen concentration had little effect on the overall response. RNA sequencing indicated that the decrease in temperature to 19°C induced a classic cold-stress response in M. aeruginosa PCC 7806, but this operated on a different timescale than the increased microcystin production. Microcystin quota showed a strong 48- to 72-h time-lag correlation to mcy gene expression, but no correlation to concurrent mcy expression. This work confirms an effect of temperature on microcystin quota and extends our understanding of the physiological nature of the response.
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Affiliation(s)
- Robbie M Martin
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Mohammad Moniruzzaman
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Gwendolyn F Stark
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Eric R Gann
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Dominique S Derminio
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States
| | - Bofan Wei
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States
| | - Ferdi L Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - Ameet Pinto
- Civil and Environmental Engineering, Northeastern University, Boston, MA, United States
| | - Gregory L Boyer
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
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27
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Rangel LM, Silva LHS, Faassen EJ, Lürling M, Ger KA. Copepod Prey Selection and Grazing Efficiency Mediated by Chemical and Morphological Defensive Traits of Cyanobacteria. Toxins (Basel) 2020; 12:toxins12070465. [PMID: 32708114 PMCID: PMC7404970 DOI: 10.3390/toxins12070465] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/13/2020] [Accepted: 07/17/2020] [Indexed: 11/25/2022] Open
Abstract
Phytoplankton anti-grazer traits control zooplankton grazing and are associated with harmful blooms. Yet, how morphological versus chemical phytoplankton defenses regulate zooplankton grazing is poorly understood. We compared zooplankton grazing and prey selection by contrasting morphological (filament length: short vs. long) and chemical (saxitoxin: STX- vs. STX+) traits of a bloom-forming cyanobacterium (Raphidiopsis) offered at different concentrations in mixed diets with an edible phytoplankton to a copepod grazer. The copepod selectively grazed on the edible prey (avoidance of cyanobacteria) even when the cyanobacterium was dominant. Avoidance of the cyanobacterium was weakest for the “short STX-” filaments and strongest for the other three strains. Hence, filament size had an effect on cyanobacterial avoidance only in the STX- treatments, while toxin production significantly increased cyanobacterial avoidance regardless of filament size. Moreover, cyanobacterial dominance reduced grazing on the edible prey by almost 50%. Results emphasize that the dominance of filamentous cyanobacteria such as Raphidiopsis can interfere with copepod grazing in a trait specific manner. For cyanobacteria, toxin production may be more effective than filament size as an anti-grazer defense against selectively grazing zooplankton such as copepods. Our results highlight how multiple phytoplankton defensive traits interact to regulate the producer-consumer link in plankton ecosystems.
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Affiliation(s)
- Luciana M. Rangel
- Laboratório de Ficologia, Museu Nacional, Departamento de Botânica, Universidade Federal do Rio de Janeiro, 20940-040 Rio de Janeiro, Brazil; (L.M.R.); (L.H.S.S.)
| | - Lúcia H. S. Silva
- Laboratório de Ficologia, Museu Nacional, Departamento de Botânica, Universidade Federal do Rio de Janeiro, 20940-040 Rio de Janeiro, Brazil; (L.M.R.); (L.H.S.S.)
| | - Elisabeth J. Faassen
- Wageningen Food Safety Research, Wageningen Research, Akkermaalsbos 2, 6708 WB Wageningen, The Netherlands;
- Department of Environmental Sciences, Aquatic Ecology and Water Quality Management Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB Wageningen, The Netherlands
| | - Miquel Lürling
- Department of Environmental Sciences, Aquatic Ecology and Water Quality Management Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB Wageningen, The Netherlands
- Correspondence: (M.L.); (K.A.G.)
| | - Kemal Ali Ger
- Center for Coastal Limnological and Marine Studies (CECLIMAR), Campus Litoral Norte, Universidade Federal de Rio Grande de Sul, 95625-000 Imbé, Brazil
- Correspondence: (M.L.); (K.A.G.)
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28
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Álvarez SD, Kruk C, Martínez de la Escalera G, Montes MA, Segura AM, Piccini C. Morphology captures toxicity in Microcystis aeruginosa complex: Evidence from a wide environmental gradient ✰. HARMFUL ALGAE 2020; 97:101854. [PMID: 32732048 DOI: 10.1016/j.hal.2020.101854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 06/04/2020] [Accepted: 06/07/2020] [Indexed: 06/11/2023]
Abstract
Blooms of the Microcystis aeruginosa complex (MAC) consist of mixtures of toxin-producing and non-toxin-producing populations, but the environmental conditions that determine their relative abundance and shift are not clear. Morphological traits reflect the responses of MAC organisms to environmental changes, thus they could be useful to improve the predictability of the abundance of both toxic and nontoxic populations. In this work, the response of MAC toxic populations to environmental conditions and their relationship with morphology (size of organisms) were investigated in different water bodies (reservoir, river, and estuary) covering wide salinity (0-33) and temperature (10-36 °C) gradients. Sub-surface water samples were collected and divided into 4 size classes (mesh size 〈20 µm, 20-60 µm, 60-150 µm and〉 150 µm) and three toxicity proxies were assessed (mcyE gene and transcripts copy numbers and microcystin concentration) for each size-class. For all the size-classes, the logarithm of the number of mcyE gene copies per sample was proportional to the logarithm of the corresponding biovolume fraction, showing that MAC biovolume is a good indicator of toxicity potential. When toxicity was analyzed through mcyE transcript abundance and microcystin concentration, the largest size fraction (>150 µm) showed the highest toxicity values of both proxies. Nevertheless, mcyE transcription and toxin production per cell were higher in the colonies retained in the 60 to 150 µm size fractions, followed by single cells (<20 µm). At the reservoir, where environmental variability is low, the total abundance of mcyE gene copies was significantly explained by MAC biovolume, regardless of the environmental conditions. However, when data from the reservoir to the estuary were modeled, biovolume and temperature (with a minor contribution of salinity and wind intensity) were selected in the best models. According to these results, the size distribution of MAC biovolume appears as a good predictor of active toxin production, being the colonies in the 60-150 µm size fraction good indicators of higher toxicity. These results can be used to predict MAC toxicity based on the size structure of the community.
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Affiliation(s)
- Susana Deus Álvarez
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Montevideo, Uruguay
| | - Carla Kruk
- Ecología Funcional de Sistemas Acuáticos, CURE-Rocha, Universidad de la República, Uruguay; Sección Limnología, IECA, Facultad de Ciencias, Universidad de la República, Uruguay
| | | | - Martín A Montes
- NASA Goddard Space Flight Center, Terrestrial Information Systems Laboratory, Greenbelt, MD 20771, United States
| | - Angel M Segura
- Modelización y Análisis de Recursos Naturales, CURE Rocha, Universidad de la República, Uruguay
| | - Claudia Piccini
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Montevideo, Uruguay.
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29
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Wejnerowski Ł, Falfushynska H, Horyn O, Osypenko I, Kokociński M, Meriluoto J, Jurczak T, Poniedziałek B, Pniewski F, Rzymski P. In Vitro Toxicological Screening of Stable and Senescing Cultures of Aphanizomenon, Planktothrix, and Raphidiopsis. Toxins (Basel) 2020; 12:E400. [PMID: 32560354 PMCID: PMC7354461 DOI: 10.3390/toxins12060400] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/20/2022] Open
Abstract
Toxicity of cyanobacteria is the subject of ongoing research, and a number of toxic metabolites have been described, their biosynthesis pathways have been elucidated, and the mechanism of their action has been established. However, several knowledge gaps still exist, e.g., some strains produce hitherto unknown toxic compounds, while the exact dynamics of exerted toxicity during cyanobacterial growth still requires further exploration. Therefore, the present study investigated the toxicity of extracts of nine freshwater strains of Aphanizomenon gracile, an Aphanizomenon sp. strain isolated from the Baltic Sea, a freshwater strain of Planktothrix agardhii, and two strains of Raphidiopsis raciborskii obtained from 25- and 70-day-old cultures. An in vitro experimental model based on Cyprinus carpio hepatocytes (oxidative stress markers, DNA fragmentation, and serine/threonine protein activity) and brain homogenate (cholinesterase activity) was employed. The studied extracts demonstrated toxicity to fish cells, and in general, all examined extracts altered at least one or more of considered parameters, indicating that they possess, to some degree, toxic potency. Although the time from which the extracts were obtained had a significant importance for the response of fish cells, we observed strong variability between the different strains and species. In some strains, extracts that originated from 25-day-old cultures triggered more harmful effects on fish cells compared to those obtained from 70-day-old cultures, whereas in other strains, we observed the opposite effect or a lack of a significant change. Our study revealed that there was no clear or common pattern regarding the degree of cyanobacterial bloom toxicity at a given stage of development. This means that young cyanobacterial blooms that are just forming can pose an equally toxic threat to aquatic vertebrates and ecosystem functioning as those that are stable or old with a tendency to collapse. This might be largely due to a high variability of strains in the bloom.
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Affiliation(s)
- Łukasz Wejnerowski
- Department of Hydrobiology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland;
| | - Halina Falfushynska
- Department of Orthopedagogy and Physical Therapy, Ternopil V. Hnatiuk National Pedagogical University, 46027 Ternopil, Ukraine; (O.H.); (I.O.)
| | - Oksana Horyn
- Department of Orthopedagogy and Physical Therapy, Ternopil V. Hnatiuk National Pedagogical University, 46027 Ternopil, Ukraine; (O.H.); (I.O.)
| | - Inna Osypenko
- Department of Orthopedagogy and Physical Therapy, Ternopil V. Hnatiuk National Pedagogical University, 46027 Ternopil, Ukraine; (O.H.); (I.O.)
| | - Mikołaj Kokociński
- Department of Hydrobiology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland;
| | - Jussi Meriluoto
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland;
| | - Tomasz Jurczak
- United Nations Educational, Scientific and Cultural Organization (UNESCO) Chair on Ecohydrology and Applied Ecology, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland;
| | - Barbara Poniedziałek
- Department of Environmental Medicine, Poznan University of Medical Sciences, Rokietnicka 8, 60-806 Poznań, Poland;
| | - Filip Pniewski
- Institute of Oceanography, University of Gdańsk, Al. Piłsudskiego 46, 81-378 Gdynia, Poland;
| | - Piotr Rzymski
- Department of Environmental Medicine, Poznan University of Medical Sciences, Rokietnicka 8, 60-806 Poznań, Poland;
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30
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Natumi R, Janssen EML. Cyanopeptide Co-Production Dynamics beyond Mirocystins and Effects of Growth Stages and Nutrient Availability. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:6063-6072. [PMID: 32302105 DOI: 10.1021/acs.est.9b07334] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Intensified cyanobacterial bloom events are of increasing global concern because of adverse effects associated with the release of bioactive compounds, including toxic cyanopeptides. Cyanobacteria can produce a variety of cyanopeptides, yet our knowledge about their abundance and co-production remains limited. We applied a suspect-screening approach, including 700 structurally known cyanopeptides, and identified 11 cyanopeptides in Microcystis aeruginosa and 17 in Dolichospermum flos-aquae. Total cyanopeptide concentrations ranged from high nmol to μmol gdry-1 with slightly higher cell quotas in the mid-exponential growth phase. Relative cyanopeptide profiles were unchanged throughout the growth cycle. We demonstrate that quantification based on microcystin-LR equivalents can introduce an error of up to 6-fold and recommend a class-equivalent approach instead. In M. aeruginosa, rarely studied cyclamides dominated (>80%) over cyanopeptolins and microcystins. While all nutrient reductions caused less growth, only lowering phosphorous and micronutrients reduced cyanopeptide production by M. aeruginosa. Similar trends were observed for D. flos-aquae and only lowering nitrogen decreased cyanopeptide production while the relative abundance of individual cyanopeptides remained stable. The synchronized production of other cyanopeptides along with microcystins emphasizes the need to make them available as reference standards to encourage more studies on their occurrence in blooms, persistence, and potential toxicity.
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Affiliation(s)
- Regiane Natumi
- Department of Environmental Chemistry, Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland
| | - Elisabeth M-L Janssen
- Department of Environmental Chemistry, Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland
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Veaudor T, Blanc-Garin V, Chenebault C, Diaz-Santos E, Sassi JF, Cassier-Chauvat C, Chauvat F. Recent Advances in the Photoautotrophic Metabolism of Cyanobacteria: Biotechnological Implications. Life (Basel) 2020; 10:life10050071. [PMID: 32438704 PMCID: PMC7281370 DOI: 10.3390/life10050071] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/16/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022] Open
Abstract
Cyanobacteria constitute the only phylum of oxygen-evolving photosynthetic prokaryotes that shaped the oxygenic atmosphere of our planet. Over time, cyanobacteria have evolved as a widely diverse group of organisms that have colonized most aquatic and soil ecosystems of our planet and constitute a large proportion of the biomass that sustains the biosphere. Cyanobacteria synthesize a vast array of biologically active metabolites that are of great interest for human health and industry, and several model cyanobacteria can be genetically manipulated. Hence, cyanobacteria are regarded as promising microbial factories for the production of chemicals from highly abundant natural resources, e.g., solar energy, CO2, minerals, and waters, eventually coupled to wastewater treatment to save costs. In this review, we summarize new important discoveries on the plasticity of the photoautotrophic metabolism of cyanobacteria, emphasizing the coordinated partitioning of carbon and nitrogen towards growth or compound storage, and the importance of these processes for biotechnological perspectives. We also emphasize the importance of redox regulation (including glutathionylation) on these processes, a subject which has often been overlooked.
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Affiliation(s)
- Théo Veaudor
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Victoire Blanc-Garin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Célia Chenebault
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Encarnación Diaz-Santos
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Jean-François Sassi
- Commissariat à l’énergie atomique et aux énergies alternatives (CEA), Centre de Cadarache St Paul Lez, 13108 Durance, France;
| | - Corinne Cassier-Chauvat
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Franck Chauvat
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
- Correspondence: ; Tel.: +33-1-69-08-78-11
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Lin SR, Chen YH, Tseng FJ, Weng CF. The production and bioactivity of prodigiosin: quo vadis? Drug Discov Today 2020; 25:828-836. [PMID: 32251776 DOI: 10.1016/j.drudis.2020.03.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/11/2020] [Accepted: 03/26/2020] [Indexed: 12/13/2022]
Abstract
Prodigiosin (PG), a red tripyrrole pigment, belongs to a member of the prodiginine family and is normally secreted by various sources including Serratia marcescens and other Gram-negative bacteria. The studies of PG have received innovative devotion as a result of reported antimicrobial, larvicidal and anti-nematoid immunomodulation and antitumor properties, owing to its antibiotic and cytotoxic activities. This review provides a comprehensive summary of research undertaken toward the isolation and structural elucidation of the prodiginine family of natural products. Additionally, the current evidence-based understanding of the biological activities and medicinal potential of PG is employed to determine the efficacy, with some reports of information related to pharmacokinetics, pharmacodynamics and toxicology.
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Affiliation(s)
- Shian-Ren Lin
- Graduated Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, 11041, Taiwan
| | - Yu-Hsin Chen
- National Museum of Marine Biology and Aquarium, Pingtung 94450, Taiwan
| | - Feng-Jen Tseng
- Department of Orthopedics, Hualien Armed Force General Hospital, Hualien 97144, Taiwan
| | - Ching-Feng Weng
- The Center of Translational Medicine, Department of Basic Medical Science, Xiamen Medical College, Xiamen 361023, Fujian, China; Institute of Respiratory Disease, Department of Basic Medical Science, Xiamen Medical College, Xiamen 361023, Fujian, China.
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Effects of Nutrient Limitation on the Synthesis of N-Rich Phytoplankton Toxins: A Meta-Analysis. Toxins (Basel) 2020; 12:toxins12040221. [PMID: 32244741 PMCID: PMC7232484 DOI: 10.3390/toxins12040221] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 11/21/2022] Open
Abstract
Eutrophication has played a major role in the worldwide increase of harmful algal blooms (HABs). Higher input of key nutrients, such as nitrogen (N) and phosphorus (P), can stimulate the growth of harmful algal species in freshwater, estuarine, and coastal marine ecosystems. Some HAB-forming taxa, particularly several cyanobacteria and dinoflagellate species, are harmful through the production of N-rich toxins that have detrimental effects on the environment and human health. Here, we test how changes in nutrient availability affect N-rich toxin synthesis in cyanobacteria and dinoflagellates using a meta-analysis approach. Overall, N-rich toxin content showed an increase with P limitation, while it tended to decrease with N limitation, but we also observed substantial variation in responses both within and across genera and toxin groups. For instance, in response to N limitation, microcystin content varied from a 297% decrease up to a 273% increase, and paralytic shellfish poisoning (PSP) toxin content varied from a 204% decrease to an 82% increase. Cylindrospermopsin, produced by N2-fixing cyanobacteria, showed no clear direction in response to nutrient limitation, and cellular contents of this compound may thus vary independently of nutrient fluctuations. Our results confirm earlier reported stoichiometric regulation of N-rich phytoplankton toxins, showing increased toxin content with an increase in cellular N:P ratios, and vice versa. Thus, changes in N-rich toxin content largely follow the changes in relative cellular N content. Consequently, although nutrient limitation may limit bloom biomass and thereby bloom toxicity, our results warn that P limitation can cause accumulation of cellular toxins and thus lead to unexpected increases in bloom toxicity.
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Feng LJ, Sun XD, Zhu FP, Feng Y, Duan JL, Xiao F, Li XY, Shi Y, Wang Q, Sun JW, Liu XY, Liu JQ, Zhou LL, Wang SG, Ding Z, Tian H, Galloway TS, Yuan XZ. Nanoplastics Promote Microcystin Synthesis and Release from Cyanobacterial Microcystis aeruginosa. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:3386-3394. [PMID: 31961660 DOI: 10.1021/acs.est.9b06085] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Although the fate of nanoplastics (<100 nm) in freshwater systems is increasingly well studied, much less is known about its potential threats to cyanobacterial blooms, the ultimate phenomenon of eutrophication occurrence worldwide. Previous studies have evaluated the consequences of nanoplastics increasing the membrane permeability of microbes, however, there is no direct evidence for interactions between nanoplastics and microcystin; intracellular hepatotoxins are produced by some genera of cyanobacteria. Here, we show that the amino-modified polystyrene nanoplastics (PS-NH2) promote microcystin synthesis and release from Microcystis aeruginosa, a dominant species causing cyanobacterial blooms, even without the change of coloration. We demonstrate that PS-NH2 inhibits photosystem II efficiency, reduces organic substance synthesis, and induces oxidative stress, enhancing the synthesis of microcystin. Furthermore, PS-NH2 promotes the extracellular release of microcystin from M. aeruginosa via transporter protein upregulation and impaired cell membrane integrity. Our findings propose that the presence of nanoplastics in freshwater ecosystems might enhance the threat of eutrophication to aquatic ecology and human health.
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Affiliation(s)
- Li-Juan Feng
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Xiao-Dong Sun
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Fan-Ping Zhu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Yue Feng
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Jian-Lu Duan
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Fu Xiao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Xiang-Yu Li
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Yi Shi
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Qian Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Jia-Wen Sun
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Xiao-Yu Liu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Jia-Qi Liu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Lin-Lin Zhou
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Shu-Guang Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Zhaojun Ding
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, College of Life Science, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Huiyu Tian
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, College of Life Science, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Tamara Susan Galloway
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, Devon, U.K
| | - Xian-Zheng Yuan
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong 266237, P. R. China
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Liu F, Yazdani M, Ahner BA, Wu M. An array microhabitat device with dual gradients revealed synergistic roles of nitrogen and phosphorous in the growth of microalgae. LAB ON A CHIP 2020; 20:798-805. [PMID: 31971190 DOI: 10.1039/c9lc01153f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Harmful algal blooms (HABs) are an emerging environmental problem contaminating water resources and disrupting the balance of the ecosystems. HABs are caused by the sudden growth of photosynthetic algal cells in both fresh and marine water, and have been expanding in extent and appearing more frequently due to the climate change and population growth. Despite the urgency of the problem, the exact environmental conditions that trigger HABs are unknown. This is in part due to the lack of high throughput tools for screening environmental parameters in promoting the growth of photosynthetic microorganisms. In this article, we developed an array microhabitat device with well defined dual nutrient gradients suitable for quantitative studies of multiple environmental parameters in microalgal cell growth. This device enabled an ability to provide 64 different nutrient conditions [nitrogen (N), phosphorous (P), and N : P ratio] at the same time, and the gradient generation took less than 90 min, advancing the current pond and test tube assays in terms of time and cost. Using a photosynthetic algal cell line, Chlamydomonas reinhardtii, preconditioned in co-limited media, we revealed that N and P synergistically promoted cell growth. Interestingly, no discernible response was observed when single P or N gradient was imposed. Our work demonstrated the enabling capability of the microfluidic platform for screening effects of multiple environmental factors in photosynthetic cell growth, and highlighted the importance of the synergistic roles of environmental factors in algal cell growth.
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Affiliation(s)
- Fangchen Liu
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
| | - Mohammad Yazdani
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
| | - Beth A Ahner
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
| | - Mingming Wu
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
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Zhou Y, Li X, Xia Q, Dai R. Transcriptomic survey on the microcystins production and growth of Microcystis aeruginosa under nitrogen starvation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 700:134501. [PMID: 31689655 DOI: 10.1016/j.scitotenv.2019.134501] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/15/2019] [Accepted: 09/15/2019] [Indexed: 06/10/2023]
Abstract
Cyanobacteria are a vital component of freshwater phytoplankton, and many species are recognized for their ability to produce toxins and harmful algal blooms (HABs). Nitrogen is an essential element of all the complex macromolecules in algal cells. However, the underlying molecular mechanism of the changes in transcriptomic patterns and physiological responses in response to N starvation is poorly understood. The transcriptomes were generated via RNA-sequencing (RNA-Seq) technology to study the major metabolic pathway under N starvation. The results shed light on the mechanism of toxin production and physiological adaptations in Microcystis aeruginosa (M. aeruginosa). The cell density gradually increased during the first two days then declined over time and was finally stable at (15.50 ± 0.5) × 105 cell mL-1 after 6 days. The chlorophyll-a content and phycocyanin content of M. aeruginosa increased during the first two days and subsequently decreased markedly over time under N starvation. The variable to maximum chlorophyll fluorescence ratio (Fv/Fm ratio) decreased with time under N starvation. Most photosynthesis genes have similarity decreasing trends with growth physiological changes. The microcystins (MCs) levels generally increased first, reaching a peak value with 1.35 pg cell-1 on the fifth day, and then remained roughly constant. The genes involved in N metabolism-related gene expression were upregulated to maintain normal biological activity, while the genes involved in photosynthesis-related gene expression were downregulated to save energy. All genes encoding algae toxin synthesis were upregulated under N starvation. The observed expression patterns demonstrate that all MCs genes respond similarly to MCs production within the cell. Our results indicate the response mechanism of M. aeruginosa under N starvation and provide a comprehensive understanding of N-controlling cyanobacteria and MCs synthesis.
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Affiliation(s)
- Yanping Zhou
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Xuan Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
| | - Qiongqiong Xia
- North China Municipal Engineering Design & Research Institute Co. Ltd., Tianjin 300074, China
| | - Ruihua Dai
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
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Bouaïcha N, Miles CO, Beach DG, Labidi Z, Djabri A, Benayache NY, Nguyen-Quang T. Structural Diversity, Characterization and Toxicology of Microcystins. Toxins (Basel) 2019; 11:toxins11120714. [PMID: 31817927 PMCID: PMC6950048 DOI: 10.3390/toxins11120714] [Citation(s) in RCA: 206] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/22/2022] Open
Abstract
Hepatotoxic microcystins (MCs) are the most widespread class of cyanotoxins and the one that has most often been implicated in cyanobacterial toxicosis. One of the main challenges in studying and monitoring MCs is the great structural diversity within the class. The full chemical structure of the first MC was elucidated in the early 1980s and since then, the number of reported structural analogues has grown steadily and continues to do so, thanks largely to advances in analytical methodology. The structures of some of these analogues have been definitively elucidated after chemical isolation using a combination of techniques including nuclear magnetic resonance, amino acid analysis, and tandem mass spectrometry (MS/MS). Others have only been tentatively identified using liquid chromatography-MS/MS without chemical isolation. An understanding of the structural diversity of MCs, the genetic and environmental controls for this diversity and the impact of structure on toxicity are all essential to the ongoing study of MCs across several scientific disciplines. However, because of the diversity of MCs and the range of approaches that have been taken for characterizing them, comprehensive information on the state of knowledge in each of these areas can be challenging to gather. We have conducted an in-depth review of the literature surrounding the identification and toxicity of known MCs and present here a concise review of these topics. At present, at least 279 MCs have been reported and are tabulated here. Among these, about 20% (55 of 279) appear to be the result of chemical or biochemical transformations of MCs that can occur in the environment or during sample handling and extraction of cyanobacteria, including oxidation products, methyl esters, or post-biosynthetic metabolites. The toxicity of many MCs has also been studied using a range of different approaches and a great deal of variability can be observed between reported toxicities, even for the same congener. This review will help clarify the current state of knowledge on the structural diversity of MCs as a class and the impacts of structure on toxicity, as well as to identify gaps in knowledge that should be addressed in future research.
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Affiliation(s)
- Noureddine Bouaïcha
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
- Correspondence: ; Tel.: +33-(01)69154990; Fax: +33-(0)169155696
| | - Christopher O. Miles
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Daniel G. Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Zineb Labidi
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Amina Djabri
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Naila Yasmine Benayache
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
| | - Tri Nguyen-Quang
- Biofluids and Biosystems Modeling (BBML), Faculty of Agriculture, Dalhousie University, 39 Cox Road, Truro, B2N 5E3 Nova Scotia, Canada;
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Facey JA, Apte SC, Mitrovic SM. A Review of the Effect of Trace Metals on Freshwater Cyanobacterial Growth and Toxin Production. Toxins (Basel) 2019; 11:E643. [PMID: 31694295 PMCID: PMC6891437 DOI: 10.3390/toxins11110643] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/01/2019] [Accepted: 11/02/2019] [Indexed: 12/21/2022] Open
Abstract
Cyanobacterial blooms are becoming more common in freshwater systems, causing ecological degradation and human health risks through exposure to cyanotoxins. The role of phosphorus and nitrogen in cyanobacterial bloom formation is well documented and these are regularly the focus of management plans. There is also strong evidence that trace metals are required for a wide range of cellular processes, however their importance as a limiting factor of cyanobacterial growth in ecological systems is unclear. Furthermore, some studies have suggested a direct link between cyanotoxin production and some trace metals. This review synthesises current knowledge on the following: (1) the biochemical role of trace metals (particularly iron, cobalt, copper, manganese, molybdenum and zinc), (2) the growth limitation of cyanobacteria by trace metals, (3) the trace metal regulation of the phytoplankton community structure and (4) the role of trace metals in cyanotoxin production. Iron dominated the literature and regularly influenced bloom formation, with 15 of 18 studies indicating limitation or colimitation of cyanobacterial growth. A range of other trace metals were found to have a demonstrated capacity to limit cyanobacterial growth, and these metals require further study. The effect of trace metals on cyanotoxin production is equivocal and highly variable. Better understanding the role of trace metals in cyanobacterial growth and bloom formation is an essential component of freshwater management and a direction for future research.
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Affiliation(s)
- Jordan A. Facey
- Freshwater and Estuarine Research Group, School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo 2007, Australia
| | | | - Simon M. Mitrovic
- Freshwater and Estuarine Research Group, School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo 2007, Australia
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Gao Y, Shimizu K, Amano C, Wang X, Pham TL, Sugiura N, Utsumi M. Response of microcystin biosynthesis and its biosynthesis gene cluster transcription in Microcystis aeruginosa on electrochemical oxidation. ENVIRONMENTAL TECHNOLOGY 2019; 40:3593-3601. [PMID: 29806796 DOI: 10.1080/09593330.2018.1482371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
Microcystin-LR (MC-LR), which is one of the most commonly found microcystins (MCs) in fresh water, has been proved to be a potential tumour promoter and classified as 2B by the International Agency for Research on Cancer. MC-LR decomposition and inhibition of MC-LR production in Microcystis aeruginosa were investigated under electrolysis condition using an electrolysis cell consisting of Ti/Pt electrodes and Nafion membrane. The relationship between the decrease in MC-LR concentration and transcription of MC-LR synthesis gene clusters was determined by performing real-time reverse transcription polymerase chain reaction (RT-qPCR) to monitor changes in the levels of transcription encoding mcyB and mcyD (cDNA to DNA) in M. aeruginosa NIES 1086 under electrolysis condition and three different conditions (i.e. oxygenated, air aerated and unaerated) as controls. Cell density decreased from day 2 under electrolysis than under the three controls. Intracellular MC-LR concentration was approximately 33 fg cell-1 under electrolysis from days 4 to 8, while those in the other conditions ranged in 40-50 fg cell-1. The mcyB transcription continuously decreased from day 2 to nondetectable level in day 6 under electrolysis, while this transcription was stabilised under the three controls. This result suggested that oxidative stress, such as hydroxyl radicals, played an important role in the down-regulation of mcyB and mcyD gene transcription level and the MC-LR concentration and cell density of M. aeruginosa.
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Affiliation(s)
- Yu Gao
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology , Qingdao , People's Republic of China
- Graduate School of Life and Environment Science, University of Tsukuba , Tsukuba , Japan
| | - Kazuya Shimizu
- Faculty of Life Science, Toyo University , Gunma , Japan
| | - Chie Amano
- Graduate School of Life and Environment Science, University of Tsukuba , Tsukuba , Japan
- Department of Limnology and Bio-Oceanography, University of Vienna , Wien , Austria
| | - Xin Wang
- Graduate School of Life and Environment Science, University of Tsukuba , Tsukuba , Japan
- School of Envrionment and Energy, Peking University , Shenzhen , People's Republic of China
| | - Thanh Luu Pham
- Graduate School of Life and Environment Science, University of Tsukuba , Tsukuba , Japan
| | - Norio Sugiura
- Graduate School of Life and Environment Science, University of Tsukuba , Tsukuba , Japan
- Malaysia-Japan International Institute of Technology, University Technology Malaysia , Johor Bahru , Malaysia
| | - Motoo Utsumi
- Graduate School of Life and Environment Science, University of Tsukuba , Tsukuba , Japan
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Chen Q, Wang M, Zhang J, Shi W, Mynett AE, Yan H, Hu L. Physiological effects of nitrate, ammonium, and urea on the growth and microcystins contamination of Microcystis aeruginosa: Implication for nitrogen mitigation. WATER RESEARCH 2019; 163:114890. [PMID: 31351354 DOI: 10.1016/j.watres.2019.114890] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/18/2019] [Accepted: 07/19/2019] [Indexed: 05/03/2023]
Abstract
The effects of three commonly bioavailable nitrogen (N) sources (nitrate, ammonium, and urea) on regulating the growth and microcystins (MCs) production of Microcystis aeruginosa (M. aeruginosa) at environmentally relevant concentrations were investigated from a physiological perspective. Changes in amino acid quotas as well as the transcripts of target genes associated with N metabolism (ntcA, pipX and glnB) and toxin formation (mcyA and mcyD) were determined. Results indicated that increases in nitrate and urea concentrations enhanced M. aeruginosa growth, but high ammonium concentration (7 mg-N/L) suppressed the growth. The total intracellular MCs (IMCs) content was well correlated (0.65, p < 0.001) to amino acids (the sum of methionine, leucine, serine, alanine, arginine, glutamic acid, and aspartic acid) associated with MCs production. Ammonium favors amino acid synthesis in M. aeruginosa, thus cells grown under high concentrations of ammonium (7 mg-N/L) had sufficient precursors for MCs production, which might lead to higher IMCs. Both high and low ammonium concentration resulted in high total extracellular MCs (EMCs) level in water, despite of their different mechanisms. These results indicated that mitigation of nitrogen in eutrophic waters should be very cautious of unexpected risks, as the reduction of ammonium may have the risk of stimulating M. aeruginosa growth or increasing EMCs levels.
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Affiliation(s)
- Qiuwen Chen
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China; Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing, 210029, China.
| | - Min Wang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China; Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Jianyun Zhang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China.
| | - Wenqing Shi
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, 210029, China; Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Arthur E Mynett
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Hanlu Yan
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
| | - Liuming Hu
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing, 210029, China
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41
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Omidi A, Esterhuizen-Londt M, Pflugmacher S. Interspecies interactions between Microcystis aeruginosa PCC 7806 and Desmodesmus subspicatus SAG 86.81 in a co-cultivation system at various growth phases. ENVIRONMENT INTERNATIONAL 2019; 131:105052. [PMID: 31357091 DOI: 10.1016/j.envint.2019.105052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
In lakes, cyanobacterial blooms are frequently associated with green algae and dominate the phytoplankton community in successive waves. In the present study, the interactions between Microcystis aeruginosa PCC 7806 and Desmodesmus subspicatus were studied to clarify the probable ecological significance of algal secondary metabolites; focusing on the role of cyanotoxin 'microcystin-LR' (MC-LR). A dialysis co-cultivation technique was applied where M. aeruginosa was grown inside and D. subspicatus was cultured outside of the dialysis tubing. The concentration of the intra- and extracellular MC-LR and the growth of two species were measured at different time points over a period of one month. Additionally, the growth of the two species in the culture filtrate of one another and the effect of the purified MC-LR on the growth of the green alga were studied. The results indicated that the co-existing species could affect each other depending on the growth phases. Despite the early dominance of D. subspicatus during the logarithmic phase, M. aeruginosa suppressed the growth of the green alga at the stationary phase, which coincided with increased MC production and release. However, the inhibitory effects of Microcystis might be related to its other extracellular metabolites rather than, or possibly in addition to, MC.
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Affiliation(s)
- Azam Omidi
- Technische Universität Berlin, Chair Ecological Impact Research and Ecotoxicology, Ernst-Reuter-Platz 1, 10587 Berlin, Germany.
| | - Maranda Esterhuizen-Londt
- University of Helsinki, Aquatic Ecotoxicology in an Urban Environment, Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, Niemenkatu 73, 15140 Lahti, Finland; Korean Institute of Science and Technology Europe (KIST), Joint laboratory of Applied Ecotoxicology, Campus E7 1, 66123 Saarbrücken, Germany; Helsinki Institute of Sustainability (HELSUS), Fabianinkatu 33, 00014 Helsinki, Finland.
| | - Stephan Pflugmacher
- University of Helsinki, Aquatic Ecotoxicology in an Urban Environment, Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, Niemenkatu 73, 15140 Lahti, Finland; Korean Institute of Science and Technology Europe (KIST), Joint laboratory of Applied Ecotoxicology, Campus E7 1, 66123 Saarbrücken, Germany; Helsinki Institute of Sustainability (HELSUS), Fabianinkatu 33, 00014 Helsinki, Finland.
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42
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Pan D, Pavagadhi S, Umashankar S, Rai A, Benke PI, Rai M, Saxena G, Gangu V, Swarup S. Resource partitioning strategies during toxin production in Microcystis aeruginosa revealed by integrative omics analysis. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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43
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Qian ZY, Chen X, Zhu HT, Shi JZ, Gong TT, Xian QM. Study on the cyanobacterial toxin metabolism of Microcystis aeruginosa in nitrogen-starved conditions by a stable isotope labelling method. JOURNAL OF HAZARDOUS MATERIALS 2019; 373:558-564. [PMID: 30952000 DOI: 10.1016/j.jhazmat.2019.03.127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 03/16/2019] [Accepted: 03/30/2019] [Indexed: 06/09/2023]
Abstract
In this study, the biosynthesis of microcystins (MCs) was investigated after long-term nitrogen-starved conditions in cyanobacterium Microcystis aeruginosa. The results demonstrated that the algal cells were able to survive in a non-growing state with nitrogen starvation for more than one month. The physiological properties of the algal cells were studied to elucidate the mechanisms of viability under nitrogen-deprivation conditions. After the state of nitrogen chlorosis, new toxins could be resynthesized and tracked using 15N-stable isotope-labelled nitrogen. Nitrogen starvation of nutritionally replete cells resulted in a significant increase of microcystin-LY (MC-LY), thereby suggesting that MC-LY may undergo catabolism to provide nitrogen or that MC-LY may be produced to play an important role in the cell in response to nitrogen deprivation. The rank order of different types of nitrogen in algal cells assimilation was N-ammonium > N-urea > N-nitrate > N-alanine. The relationship between the production of toxin variants and various environmental conditions is an interesting issue for future research and may help improve the understanding of the ecological role of cyanobacterial toxins.
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Affiliation(s)
- Zong-Yao Qian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Xiao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - He-Te Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Jun-Zhe Shi
- Wuxi Environmental Monitoring Central Station, Wuxi, 214121, China
| | - Ting-Ting Gong
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Qi-Ming Xian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
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44
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Banerji A, Bagley MJ, Shoemaker JA, Tettenhorst DR, Nietch CT, Allen HJ, Santo Domingo JW. Evaluating putative ecological drivers of microcystin spatiotemporal dynamics using metabarcoding and environmental data. HARMFUL ALGAE 2019; 86:84-95. [PMID: 31358280 PMCID: PMC7877229 DOI: 10.1016/j.hal.2019.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/19/2019] [Accepted: 05/07/2019] [Indexed: 05/03/2023]
Abstract
Microcystin is a cyanobacterial hepatotoxin of global concern. Understanding the environmental factors that cause high concentrations of microcystin is crucial to the development of lake management strategies that minimize harmful exposures. While the literature is replete with studies linking cyanobacterial production of microcystin to changes in various nutrients, abiotic stressors, grazers, and competitors, no single biotic or abiotic factor has been shown to be reliably predictive of microcystin concentrations in complex ecosystems. We performed random forest regression analyses with 16S and 18S rRNA gene sequencing data and environmental data to determine which putative ecological drivers best explained spatiotemporal variation in total microcystin and several individual congeners in a eutrophic freshwater reservoir. Model performance was best for predicting concentrations of the congener MC-LR, with ca. 88% of spatiotemporal variance explained. Most of the variance was associated with changes in the relative abundance of the cyanobacterial genus Microcystis. Follow-up RF regression analyses revealed that factors that were the most important in predicting MC-LR were also the most important in predicting Microcystis population dynamics. We discuss how these results relate to prevailing ecological hypotheses regarding the function of microcystin.
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Affiliation(s)
- A Banerji
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - M J Bagley
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - J A Shoemaker
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - D R Tettenhorst
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - C T Nietch
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - H J Allen
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
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45
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Violi JP, Mitrovic SM, Colville A, Main BJ, Rodgers KJ. Prevalence of β-methylamino-L-alanine (BMAA) and its isomers in freshwater cyanobacteria isolated from eastern Australia. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 172:72-81. [PMID: 30682636 DOI: 10.1016/j.ecoenv.2019.01.046] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 06/09/2023]
Abstract
Environmental exposure to the amino acid β-methylamino-L-alanine (BMAA) was linked to the high incidence of neurodegenerative disease first reported on the island of Guam in the 1940s and has more recently been implicated in an increased incidence of amyotrophic lateral sclerosis (ALS) in parts of the USA. BMAA has been shown to be produced by a range of cyanobacteria and some marine diatoms and dinoflagellates in different parts of the world. BMAA is commonly found with two of its constitutional isomers: 2,4- diaminobutyric acid (2,4-DAB) and N-(2-aminoethyl) glycine (AEG). These isomers are thought to be co-produced by the same organisms that produce BMAA and MS/MS analysis following LC separation can add an additional level of specificity over LC-FL. Although the presence of BMAA and 2,4-DAB in surface scum samples from several sites in Australia has been reported, which Australian cyanobacterial species are capable of BMAA, 2,4-DAB and AEG production remains unknown. The aims of the present studies were to identify some of the cyanobacterial genera or species that can produce BMAA, 2,4-DAB and AEG in freshwater cyanobacteria blooms in eastern Australia. Eleven freshwater sites were sampled and from these, 19 single-species cyanobacterial cultures were established. Amino acids were extracted from cyanobacterial cultures and analysed using liquid chromatography-tandem mass spectrometry. BMAA was detected in 17 of the 19 isolates, 2,4-DAB was detected in all isolates, and AEG was detected in 18 of the 19 isolates, showing the prevalence of these amino acids in Australian freshwater cyanobacteria. Concentrations of all three isomers in Australian cyanobacteria were generally higher than the concentrations reported elsewhere. This study confirmed the presence of BMAA and its isomers in cyanobacteria isolated from eastern Australian freshwater systems, and determined which Australian cyanobacterial genera or species were capable of producing them when cultured under laboratory conditions.
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Affiliation(s)
- Jake P Violi
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Simon M Mitrovic
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Anne Colville
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Brendan J Main
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
| | - Kenneth J Rodgers
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia.
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Kumar P, Hegde K, Brar SK, Cledon M, Kermanshahi-Pour A. Potential of biological approaches for cyanotoxin removal from drinking water: A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 172:488-503. [PMID: 30738231 DOI: 10.1016/j.ecoenv.2019.01.066] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 01/20/2019] [Accepted: 01/22/2019] [Indexed: 05/20/2023]
Abstract
Biological treatment of cyanotoxins has gained much importance in recent decades and holds a promise to work in coordination with various physicochemical treatments. In drinking water treatment plants (DWTPs), effective removal of cyanotoxins with reduced toxicity is a primary concern. Commonly used treatments, such as ozonation, chlorination or activated carbon, undergo significant changes in their operating conditions (mainly dosage) to counter the variation in different environmental parameters, such as pH, temperature, and high cyanotoxin concentration. Presence of metal ions, natural organic matter (NOM), and other chemicals demand higher dosage and hence affect the activation energy to efficiently break down the cyanotoxin molecule. Due to these higher dose requirements, the treatment leads to the formation of toxic metabolites at a concentration high enough to break the guideline values. Biological methods of cyanotoxin removal proceed via enzymatic pathway where the protein-encoding genes are often responsible for the compound breakdown into non-toxic metabolites. However, in contrast to the chemical treatment, the biological processes advance at a much slower kinetic rate, predominantly due to a longer onset period (high lag phase). In fact, more than 90% of the studies reported on the biological degradation of the cyanotoxins attribute the biodegradation to the bacterial suspension. This suspended growth limits the mass transfer kinetics due to the presence of metal ions, NOMs and, other oxidizable matter, which further prolongs the lag phase and makes biological process toxic-free, albeit less efficient. In this context, this review attempts to bring out the importance of the attached growth mechanism, in particular, the biofilm-based treatment approaches which can enhance the biodegradation rate.
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Affiliation(s)
- Pratik Kumar
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec, Canada G1K 9A9
| | | | - Satinder Kaur Brar
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec, Canada G1K 9A9; Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, Canada M3J 1P3.
| | - Maximiliano Cledon
- CIMAS (CONICET, UnComa, Rio Negro), Güemes 1030, San Antonio Oeste, Rio Negro, Argentina
| | - Azadeh Kermanshahi-Pour
- Biorefining and Remediation Laboratory, Department of Process Engineering and Applied Science, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia, Canada B3J 1Z1
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47
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Li H, Alsanea A, Barber M, Goel R. High-throughput DNA sequencing reveals the dominance of pico- and other filamentous cyanobacteria in an urban freshwater Lake. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 661:465-480. [PMID: 30677691 DOI: 10.1016/j.scitotenv.2019.01.141] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 01/10/2019] [Accepted: 01/12/2019] [Indexed: 06/09/2023]
Abstract
The current study presents findings related to algal blooms in a fresh water lake, which has been experiencing severe cyanobacterial blooms (CyanoHABs). Primarily, picocyanobacteria belonging to the genus Synechococcus and filamentous cyanobacterial group belonging to Aphanizomenon and Dolichospermum dominated top water column during non-bloom and bloom periods respectively. The dominance of Synechococcus in early summer informs that blooming in Utah Lake starts in early summer and then later is taken over by other bloom-forming cyanobacteria, such as species belonging to the genus Aphanizomenon. A strong negative correlation (r = -0.9, p < 0.001) was found between the occurrence of Aphanizomenon and Synechococcus which correlates very well with the fact that the blooms of these two different cyanobacteria never coexisted. The predominance of cyanobacteria in 2017 was attributed more to temperature (r = 0.18, p < 0.001). The Actinobacteria was negatively correlated with primary production and high chlorophyll a concentration. Flavobacterium and Limnohabitans were the main phytoplankton colonizers and predators detected that could secrete extracellular enzymes to degrade algal exudates (such as proteins and polysaccharides). Additionally, cyanotoxins producers Microcystis aeruginosa and Planktothrix accounted for up to 12.43% and 7.04% of total cyanobacteria abundance during blooms. The relative abundance of chloroplast reads was overall lower than the cyanobacteria reads, except for the May 5th sampling in 2017. There was inter-annual variability in the bloom-associated heterotrophic bacterial populations, but these populations were consistent with bloom-associated bacterial populations found in other lakes. Community diversity analysis for both Shannon and Simpson indices indicated lower community diversity during the bloom period. The beta diversity conducted by PCoA and UPGMA trees suggested the significant temporal rather than spatial impacts on shaping the phytoplankton community structures during the summer season.
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Affiliation(s)
- Hanyan Li
- Department of Civil and Environmental Engineering, University of Utah, UT, USA
| | - Anwar Alsanea
- Department of Civil and Environmental Engineering, University of Utah, UT, USA
| | - Michael Barber
- Department of Civil and Environmental Engineering, University of Utah, UT, USA
| | - Ramesh Goel
- Department of Civil and Environmental Engineering, University of Utah, UT, USA.
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48
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Zhou Y, Zhang X, Li X, Jia P, Dai R. Evaluation of changes in Microcystis aeruginosa growth and microcystin production by urea via transcriptomic surveys. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 655:181-187. [PMID: 30469064 DOI: 10.1016/j.scitotenv.2018.11.100] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 11/02/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
The freshwater cyanobacteria, Microcystis aeruginosa (M. aeruginosa), is well known to produce microcystins (MCs) and induce the formation of harmful algal blooms (HABs) in aquatic environments, but the effects that urea fertilizer has on cyanobacterial growth and toxin production from a molecular biology perspective remain poorly understood. We evaluated changes in the growth and toxicity of M. aeruginosa cultured under different conditions of nitrogen (N) starvation (NN), low nitrogen (LN), and high nitrogen (HN). Cell density and chlorophyll-a concentrations decreased in cyanobacteria exposed to N starvation and increased following the addition of urea, whereas MCs content increased to a peak and then decreased after urea addition. Transcriptomic analysis confirmed that most genes encoding MCs and genes involved in N metabolic pathways were upregulated under N starvation and LN conditions, whereas these genes were downregulated under HN conditions. Our results offer important insights into the exploring N in controlling the formation of HABs and toxin production based on both physiological and molecular response.
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Affiliation(s)
- Yanping Zhou
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xufeng Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xuan Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Peili Jia
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Ruihua Dai
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
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49
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Hou X, Huang J, Tang J, Wang N, Zhang L, Gu L, Sun Y, Yang Z, Huang Y. Allelopathic inhibition of juglone (5-hydroxy-1,4-naphthoquinone) on the growth and physiological performance in Microcystis aeruginosa. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 232:382-386. [PMID: 30500701 DOI: 10.1016/j.jenvman.2018.11.105] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/19/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
The elimination of cyanobacteria blooms has become an urgent concern in aquatic environmental protection. Allelopathic control is considered a potential approach because of its exclusive and ecological safety properties. The present study evaluated the allelopathic effect of juglone, a derivative from the genus Juglans, on the toxic Microcystis aeruginosa. Juglone at 3.0-9.0 mg L-1 notably depressed the cell proliferation of M. aeruginosa. The cell abundance treated by 9.0 mg L-1 juglone decreased by 75% after an 11-day exposure. The antioxidant enzyme activity (SOD and CAT) in juglone groups increased remarkably, suggesting juglone-induced oxidant stress in the M. aeruginosa cells. Juglone exposure enhanced the intracellular and extracellular microcystin contents per cell. Nonetheless, the total amount of microcystins in the juglone-treated cyanobacterial system did not increase because of the decreased cell abundance. These results indicated the application potential of juglone for M. aeruginosa extermination.
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Affiliation(s)
- Xinying Hou
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Jing Huang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Jinghong Tang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Na Wang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Lu Zhang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Lei Gu
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Yunfei Sun
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Zhou Yang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Yuan Huang
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
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50
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Wang M, Shi W, Chen Q, Zhang J, Yi Q, Hu L. Effects of nutrient temporal variations on toxic genotype and microcystin concentration in two eutrophic lakes. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 166:192-199. [PMID: 30269014 DOI: 10.1016/j.ecoenv.2018.09.095] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/19/2018] [Accepted: 09/21/2018] [Indexed: 06/08/2023]
Abstract
Harmful cyanobacterial blooms are a growing threat to freshwater ecosystems worldwide due to the production of microcystin (MC), which can have detrimental effects on water quality and human health. The relations between MC-producing Microcystis, MC production, and environmental variables especially nutrient conditions in eutrophic lakes, Lake Taihu and Lake Yanghe, were investigated during the bloom season of 2015. Results showed that toxigenic cells contributed to 8.94-75.68% and 7.87-58.69% of the total Microcystis in Lake Taihu and Lake Yanghe, respectively. The dynamics of toxigenic cells and MC production were positively associated with NH3-N concentration in Lake Taihu, while positively associated with the concentrations of TP, TDP and PO4-P in Lake Yanghe, indicating that the dominant nutrient factor affecting the toxic blooms was nitrogen in Lake Taihu, whereas it was phosphorus in Lake Yanghe. The significant relationship between TLR eq (total MC after transformation of MC-RR and MC-YR into MC-LR) and Chlorophyll-a (Chl-a) concentration implied that Chl-a could be an alternative measure to predict MC risk in the two lakes, and the safe threshold value of Chl-a was proposed as 25.38 and 31.06 μg/L in Lake Taihu and Lake Yanghe, respectively.
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Affiliation(s)
- Min Wang
- School of Life Sciences, University of Science and Technology of China, Hefei 230026, China; Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wenqing Shi
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China
| | - Qiuwen Chen
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China.
| | - Jianyun Zhang
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China
| | - Qitao Yi
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China
| | - Liuming Hu
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China
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