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Heterotrophic Bacteria Dominate Catalase Expression during Microcystis Blooms. Appl Environ Microbiol 2022; 88:e0254421. [PMID: 35862723 PMCID: PMC9328184 DOI: 10.1128/aem.02544-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In the oligotrophic oceans, key autotrophs depend on "helper" bacteria to reduce oxidative stress from hydrogen peroxide (H2O2) in the extracellular environment. H2O2 is also a ubiquitous stressor in freshwaters, but the effects of H2O2 on autotrophs and their interactions with bacteria are less well understood in freshwaters. Naturally occurring H2O2 in freshwater systems is proposed to impact the proportion of microcystin-producing (toxic) and non-microcystin-producing (nontoxic) Microcystis in blooms, which influences toxin concentrations and human health impacts. However, how different strains of Microcystis respond to naturally occurring H2O2 concentrations and the microbes responsible for H2O2 decomposition in freshwater cyanobacterial blooms are unknown. To address these knowledge gaps, we used metagenomics and metatranscriptomics to track the presence and expression of genes for H2O2 decomposition by microbes during a cyanobacterial bloom in western Lake Erie in the summer of 2014. katG encodes the key enzyme for decomposing extracellular H2O2 but was absent in most Microcystis cells. katG transcript relative abundance was dominated by heterotrophic bacteria. In axenic Microcystis cultures, an H2O2 scavenger (pyruvate) significantly improved growth rates of one toxic strain while other toxic and nontoxic strains were unaffected. These results indicate that heterotrophic bacteria play a key role in H2O2 decomposition in Microcystis blooms and suggest that their activity may affect the fitness of some Microcystis strains and thus the strain composition of Microcystis blooms but not along a toxic versus nontoxic dichotomy. IMPORTANCE Cyanobacterial harmful algal blooms (CHABs) threaten freshwater ecosystems globally through the production of toxins. Toxin production by cyanobacterial species and strains during CHABs varies widely over time and space, but the ecological drivers of the succession of toxin-producing species remain unclear. Hydrogen peroxide (H2O2) is ubiquitous in natural waters, inhibits microbial growth, and may determine the relative proportions of Microcystis strains during blooms. However, the mechanisms and organismal interactions involved in H2O2 decomposition are unexplored in CHABs. This study shows that some strains of bloom-forming freshwater cyanobacteria benefit from detoxification of H2O2 by associated heterotrophic bacteria, which may impact bloom development.
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52
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Chen B, Pan Y, Chen Y, Zhang Z, Yang Z, Zheng M, Lu T, Jiang L, Qian H. TiO 2 nanoparticles exert an adverse effect on aquatic microbial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 831:154942. [PMID: 35367556 DOI: 10.1016/j.scitotenv.2022.154942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 03/25/2022] [Accepted: 03/27/2022] [Indexed: 06/14/2023]
Abstract
Titanium dioxide nanoparticle (n-TiO2) is a widely used nanomaterial, which is inevitably released as a residue into aquatic ecosystems during material production and usage. However, the effects of n-TiO2 on aquatic microbial communities have not been completely elucidated. This study examined the toxic effects of n-TiO2 on eukaryotic and prokaryotic microbial communities in freshwater environments. We determined that n-TiO2 had a greater inhibitory effect on the growth of eukaryotic algae than cyanobacteria in monocultures. A similar phenomenon was observed in a microcosm experiment, revealing that n-TiO2 slightly reduced the content of chlorophyll-a but evidently increased the phycocyanin content. Moreover, the alpha diversity of the eukaryotic community was not affected, whereas its beta diversity increased with exposure to n-TiO2. Although n-TiO2 altered the composition of freshwater microbial communities, it did not change the functions of the prokaryotic community, which might be attributed to the functional redundancy of microbiota. Co-occurrence network analysis indicated that n-TiO2 destabilized the freshwater community, especially the eukaryotic community, and potentially disturbed the aquatic ecosystem. Our study revealed that the ecological risk of n-TiO2 on aquatic microbial communities is complex; hence, rational utilization of n-TiO2 should be emphasized.
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Affiliation(s)
- Bingfeng Chen
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Yizhou Pan
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Yiling Chen
- Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Zhenyan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Zhihan Yang
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Meng Zheng
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Tao Lu
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Liying Jiang
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China.
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Yan M, Jin H, Pan C, Hang H, Li D, Han X. Movement Disorder and Neurotoxicity Induced by Chronic Exposure to Microcystin-LR in Mice. Mol Neurobiol 2022; 59:5516-5531. [PMID: 35732866 DOI: 10.1007/s12035-022-02919-y] [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: 04/06/2022] [Accepted: 06/07/2022] [Indexed: 10/17/2022]
Abstract
Microcystins are produced by some species of cyanobacteria, which are hazardous materials to the environment and human beings. It has been demonstrated that microcystin-LR (MC-LR) could disrupt the blood-brain barrier and cause learning and memory deficits, but the neurotoxicity of MC-LR on motor function remains unclear. In this study, the mice were exposed to MC-LR dissolved in drinking water at doses of 1, 7.5, or 15 μg/L for 15 months. We observed that 15 μg/L MC-LR could enter mouse brain tissues such as the cortex, hippocampus, and substantia nigra (SN). And 15 μg/L MC-LR also caused hypokinesia in mice and induced the loss and apoptosis of SN dopaminergic neurons (DA neurons). Meanwhile, MC-LR induced the accumulation of alpha synuclein (α-syn) in DA neurons and decreased the proteins of tyrosine hydroxylase (TH), dopa decarboxylase (DDC) and dopamine transporter (DAT), resulting in a reduction in dopamine (DA) content, which are pathological features of Parkinson's disease (PD). These results suggested that chronic MC-LR might induce PD-like lesions in mice. Moreover, chronic MC-LR exposure caused the inflammatory response in the SN, manifested by the increased numbers of glial cells and the release of inflammatory factors (TNF-α, MCP-1, and IL-6). In vitro, it was proved that MC-LR mediated SH-SY5Y cell apoptosis by activating oxidative stress and damaging mitochondria. Collectively, this study revealed a novel molecular mechanism for MC-LR neurotoxicity with significant implications for human health and the public environment.
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Affiliation(s)
- Minghao Yan
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Haibo Jin
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Chun Pan
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Hexing Hang
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China.,Department of Hepatopancreatobiliary Surgery, Drum Tower Hospital, Medical School of Nanjing University, Zhongshan Road 321, Jiangsu Province, 210008, China
| | - Dongmei Li
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China. .,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China.
| | - Xiaodong Han
- Immunology and Reproduction Biology Laboratory & State Key Laboratory of Analytical Chemistry for Life Science, Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China. .,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, Jiangsu, China.
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54
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Li J, Cao L, Guo Z. Joint effects and mechanisms of luteolin and kaempferol on toxigenic Microcystis growth-Comprehensive analysis on two isomers interaction in binary mixture. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 312:114904. [PMID: 35344874 DOI: 10.1016/j.jenvman.2022.114904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/27/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
Allelochemicals are widely accepted as promising algaecide to mitigate Microcystis-dominated cyanobacterial blooms (MCBs). Allelopathic algicidal effect of single luteolin or kaempferol against Microcystis had been confirmed, but their joint effect against Microcystis was unclear. This study comprehensively explored time-dependent joint effect and mechanisms of luteolin and kaempferol on Microcystis growth during 14 day-test. The 50%-inhibitory threshold of their mixture (IC50 mix) was verified as 4.872 and 5.211 mg/L at equitoxic ratio, and 5.167 and 4.487 mg/L at equivalent ratio, respectively, on day 8 and 14. Using toxicity unit, isobologram and predictive models, results revealed that luteolin and kaempferol at equivalent ratio interacted additively at lower, median and higher dosages, while at equitoxic ratio interacted additively at lower dosage but synergistically at median and higher dosages in Microcystis on day 8 and 14, implying that their equitoxic mixture posed better algicidal effect against Microcystis. Various dosages of equitoxic mixture concurrently decreased aqueous and total microcystins (MCs) contents along test. Thus, luteolin and kaempferol could be jointly applied as high-efficacy and eco-safe algaecide with declined MCs pollution risks. As mixture dosage elevated, more strongly weakened cellular MCs retention and inhibited cellular photosynthetic pigments content during late stage, as well as decreased aqueous MCs content long test, jointly explained increasing growth inhibition ratio with rising mixture dosage. Yet, cell damage was gradually repaired due to early stimulated antioxidant defense at each mixture dosage, thus cell damage might not be a major reason for inhibited growth under mixture stress. This study provided novel insights and guidance to coupled application of luteolin and kamepferol for mitigating MCBs and decreasing MCs pollution risks.
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Affiliation(s)
- Jieming Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, 100193, China.
| | - Linrong Cao
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, 100193, China
| | - Zhonghui Guo
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, 100193, China
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55
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A Review of Cyanophage–Host Relationships: Highlighting Cyanophages as a Potential Cyanobacteria Control Strategy. Toxins (Basel) 2022; 14:toxins14060385. [PMID: 35737046 PMCID: PMC9229316 DOI: 10.3390/toxins14060385] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Harmful algal blooms (HABs) are naturally occurring phenomena, and cyanobacteria are the most commonly occurring HABs in freshwater systems. Cyanobacteria HABs (cyanoHABs) negatively affect ecosystems and drinking water resources through the production of potent toxins. Furthermore, the frequency, duration, and distribution of cyanoHABs are increasing, and conditions that favor cyanobacteria growth are predicted to increase in the coming years. Current methods for mitigating cyanoHABs are generally short-lived and resource-intensive, and have negative impacts on non-target species. Cyanophages (viruses that specifically target cyanobacteria) have the potential to provide a highly specific control strategy with minimal impacts on non-target species and propagation in the environment. A detailed review (primarily up to 2020) of cyanophage lifecycle, diversity, and factors influencing infectivity is provided in this paper, along with a discussion of cyanophage and host cyanobacteria relationships for seven prominent cyanoHAB-forming genera in North America, including: Synechococcus, Microcystis, Dolichospermum, Aphanizomenon, Cylindrospermopsis, Planktothrix, and Lyngbya. Lastly, factors affecting the potential application of cyanophages as a cyanoHAB control strategy are discussed, including efficacy considerations, optimization, and scalability for large-scale applications.
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56
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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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57
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Latour D, Perrière F, Purdie D. Higher sensitivity to hydrogen peroxide and light stress conditions of the microcystin producer Microcystis aeruginosa sp PCC7806 compared to non-producer strains. HARMFUL ALGAE 2022; 114:102219. [PMID: 35550290 DOI: 10.1016/j.hal.2022.102219] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/14/2022] [Accepted: 02/25/2022] [Indexed: 06/15/2023]
Abstract
The increasing incidence of cyanobacterial blooms with their associated production of cyanotoxins lead managers of aquatics systems to control their biomass to limit the health risk. Among the variety of existing treatment approaches, hydrogen peroxide (H2O2) shows increasing use but the effects of environmental parameters on its effectiveness are still not completely known. With the aim to assess the efficiency of H2O2 treatments in the control of cyanobacterial blooms and decrease toxic risk, we tested three Microcystis strains according to their ability to produce cyanotoxins (a microcystin-producing, non-microcystin-producing and mcyB-knockout mutant). Photochemical efficiency, percentage of living cells and microcystin cell content were compared under various hydrogen peroxide concentrations coupled with stress conditions encountered during the life cycle of cyanobacteria as darkness and high light. The microcystin-producing strain appeared the more sensitive to hydrogen peroxide treatment and to light condition, probably due to a lower rate of repair of Photo System II (PSII). We also highlighted various responses of PSII activity according to Microcystis strains which could partly explain the shift of dominant genotypes often occurring during a bloom event. Our results confirm the link between light and microcystin content and variations of microcystin contents appear as a consequence of photosynthetic activity. These findings could be of particular interest regarding water quality management, especially the use of H2O2 as a potential algaecide which seems to be more effective to use during periods of high light.
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Affiliation(s)
- Delphine Latour
- Université Clermont Auvergne, CNRS, LMGE-UMR 6023, F-63178 Aubière Cedex, France.
| | - Fanny Perrière
- Université Clermont Auvergne, CNRS, LMGE-UMR 6023, F-63178 Aubière Cedex, France
| | - Duncan Purdie
- University of Southampton, National Oceanography Centre, Waterfront Campus, European Way, Southampton SO14 3ZH, United Kingdom
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58
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Wu D, Zhang J, Du W, Yin Y, Guo H. Toxicity mechanism of cerium oxide nanoparticles on cyanobacteria Microcystis aeruginosa and their ecological risks. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:34010-34018. [PMID: 35031986 DOI: 10.1007/s11356-021-18090-1] [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: 08/31/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
The extensive application of cerium oxide nanoparticles (CeO2 NPs), a type of rare earth nanomaterial, led to pollution into aquatic environments. Cyanobacteria, a significant component of freshwater ecosystems, can interact with CeO2 NPs. However, little attention has been paid as to whether CeO2 NPs will have adverse effects on cyanobacteria. In the present study, Microcystis aeruginosa (FACHB-942) was exposed to different concentrations (0, 1, 10, and 50 mg/L) of CeO2 NPs. Results showed 50 mg/L CeO2 NPs inhibited algal growth (11.48% ± 5.76%), suppressed photosynthesis and induced the generation of reactive oxygen species (ROS) after 72 h exposure. The toxicity mechanism is the adsorption of CeO2 NPs on cell surface, the ROS formation and the intracellular Ce. Additionally, the intracellular microcystins (MCs) content was significantly induced (11.84% ± 1.47%) by 50 mg/L CeO2 NPs, while no significance was found in 1 and 10 mg/L CeO2 NP treatments. Results indicated high concentrations of CeO2 NPs could be toxic to algae through the adverse effects on algal growth and photosynthesis. Moreover, the promoted MCs production could also pose a threat to freshwater ecosystems due to the possible release into the environment.
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Affiliation(s)
- Di Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Juanjuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Wenchao Du
- School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Ying Yin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
- Joint International Research Centre for Critical Zone Science, University of Leeds and Nanjing University, Nanjing University, Nanjing, 210023, China.
| | - Hongyan Guo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
- Joint International Research Centre for Critical Zone Science, University of Leeds and Nanjing University, Nanjing University, Nanjing, 210023, China
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59
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Ren L, Huang J, Ding K, Wang Y, Yang Y, Zhang L, Wu H. Comparative Study of Algal Responses and Adaptation Capability to Ultraviolet Radiation with Different Nutrient Regimes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095485. [PMID: 35564879 PMCID: PMC9104955 DOI: 10.3390/ijerph19095485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/24/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023]
Abstract
Frequent outbreaks of harmful algal blooms (HABs) represent one of the most serious outcomes of eutrophication, and light radiation plays a critical role in the succession of species. Therefore, a better understanding of the impact of light radiation is essential for mitigating HABs. In this study, Chlorella pyrenoidosa and non-toxic and toxic Microcystis aeruginosa were mono-cultured and co-cultured to explore algal responses under different nutrient regimes. Comparisons were made according to photosynthetically active radiation (PAR), UV-B radiation exerted oxidative stresses, and negative effects on the photosynthesis and growth of three species under normal growth conditions, and algal adaptive responses included extracellular polymeric substance (EPS) production, the regulation of superoxide dismutase (SOD) activity, photosynthetic pigments synthesis, etc. Three species had strain-specific responses to UV-B radiation and toxic M. aeruginosa was more tolerant and showed a higher adaptation capability to UV-B in the mono-cultures, including the lower sensitivity and better self-repair efficiency. In addition to stable μmax in PAR ad UV-B treatments, higher EPS production and enhanced production of photosynthetic pigments under UV-B radiation, toxic M. aeruginosa showed a better recovery of its photosynthetic efficiency. Nutrient enrichment alleviated the negative effects of UV-B radiation on three species, and the growth of toxic M. aeruginosa was comparable between PAR and UV-B treatment. In the co-cultures with nutrient enrichment, M. aeruginosa gradually outcompeted C. pyrenoidosa in the PAR treatment and UV-B treatment enhanced the growth advantages of M. aeruginosa, when toxic M. aeruginosa showed a greater competitiveness. Overall, our study indicated the adaptation of typical algal species to ambient UV-B radiation and the stronger competitive ability of toxic M. aeruginosa in the UV-radiated waters with severer eutrophication.
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Affiliation(s)
- Lingxiao Ren
- School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China; (K.D.); (Y.W.); (L.Z.); (H.W.)
- Correspondence: ; Tel.: +86-158-5066-2170
| | - Jing Huang
- Three Gorges Beijing Enterprises Nanjing Water Group Co., Ltd., Nanjing 210000, China;
| | - Keqiang Ding
- School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China; (K.D.); (Y.W.); (L.Z.); (H.W.)
| | - Yi Wang
- School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China; (K.D.); (Y.W.); (L.Z.); (H.W.)
| | - Yangyang Yang
- School of Environmental Engineering, Xuzhou University of Technology, Xuzhou 221018, China;
| | - Lijuan Zhang
- School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China; (K.D.); (Y.W.); (L.Z.); (H.W.)
| | - Haoyu Wu
- School of Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China; (K.D.); (Y.W.); (L.Z.); (H.W.)
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60
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Liu J, Chen L, Zhang X. Current research scenario for biological effect of exogenous factors on microcystin synthesis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:26190-26201. [PMID: 35089514 DOI: 10.1007/s11356-021-18256-x] [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: 09/08/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
In natural water bodies, numerous cyanobacteria have the potential to intracellularly synthesize cyanotoxins, among which microcystin (MC) is the ubiquitous toxin that has been well known to be carcinogenic for hepatocytes. MC synthesis is a complex process, which involves about 10 non-ribosomal proteins encoded by the mcy gene cluster. In the natural environments containing MC-producing cyanobacteria, a variety of external factors can affect the generation of MC by mediating the expression of synthesizing genes. These factors can be generally divided into biotic factors (e.g., daphnia, virioplankton, MC-degrading bacteria, algicidal bacteria) and abiotic factors (e.g., nutrients, physical factors, chemicals, phytochemicals, essential trace elements), which are of great significance to the effective reduction of MC. Furthermore, comparison of MC-synthesizing genes in different cyanobacterial strains was performed, and the related factors affecting MC synthesis were summarized. Then, the problems and gaps regarding the biological effect of exogenous factors on microcystin synthesis were discussed. This review article may provide new ideas for addressing the challenges and bottlenecks of MC management.
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Affiliation(s)
- Jiahui Liu
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha, China
| | - Lv Chen
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha, China
| | - Xian Zhang
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha, China.
- Hunan Provincial Key Laboratory of Clinical Epidemiology, Central South University, Changsha, China.
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61
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Trung B, Vollebregt ME, Lürling M. Warming and Salt Intrusion Affect Microcystin Production in Tropical Bloom-Forming Microcystis. Toxins (Basel) 2022; 14:toxins14030214. [PMID: 35324711 PMCID: PMC8948854 DOI: 10.3390/toxins14030214] [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: 02/17/2022] [Revised: 03/04/2022] [Accepted: 03/15/2022] [Indexed: 02/01/2023] Open
Abstract
The Vietnamese Mekong Delta is predicted to be one of the regions most impacted by climate change, causing increased temperature and salinity in inland waters. We hypothesized that the increase in temperature and salinity may impact the microcystin (MC) production of two Microcystis strains isolated in this region from a freshwater pond (strain MBC) and a brackish water pond (strain MTV). The Microcystis strains were grown at low (27 °C), medium (31 °C), high (35 °C) and extremely high (37 °C) temperature in flat photobioreactors (Algaemist). At each temperature, when cultures reached a stable state, sea salt was added to increase salinity to 4‰, 8‰, 12‰ and 16‰. MC concentrations and cell quota were reduced at high and extremely high temperatures. Salinity, in general, had comparable effects on MC concentrations and quota. At a salinity of 4‰ and 8‰, concentrations of MC per mL of culture and MC cell quota (based on chlorophyll, dry-weight and particle counts) were higher than at 0.5‰, while at the highest salinities (12‰ and 16‰) these were strongly reduced. Strain MBC produced five MC variants of which MC-RR and MC-LR were most abundant, followed by MC-YR and relatively low amounts of demethylated variants dmMC-RR and dmMC-LR. In strain MTV, MC-RR was most abundant, with traces of MC-YR and dmMC-RR only in cultures grown at 16‰ salinity. Overall, higher temperature led to lower MC concentrations and cell quota, low salinity seemed to promote MC production and high salinity reduced MC production. Hence, increased temperature and higher salinity could lead to less toxic Microcystis, but since these conditions might favour Microcystis over other competitors, the overall biomass gain could offset a lower toxicity.
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62
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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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63
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Wan X, Guo Q, Li X, Wang G, Zhao Y. Synergistic toxicity to the toxigenic Microcystis and enhanced microcystin release exposed to polycyclic aromatic hydrocarbon mixtures. Toxicon 2022; 210:49-57. [PMID: 35217023 DOI: 10.1016/j.toxicon.2022.02.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/11/2022] [Accepted: 02/20/2022] [Indexed: 11/15/2022]
Abstract
With the continued influx and accumulation of polycyclic aromatic hydrocarbons (PAHs) in eutrophic waters, the effects of PAHs on cyanobacteria bloom need to be clarified. PAHs usually existed as mixtures in aquatic environments, but the combined toxicity of PAH mixtures to toxigenic cyanobacteria remained unknown. This study investigated the effects of phenanthrene (Phe) and benzo [a]pyrene (BaP), alone or in combination, on the growth and physiology of Microcystis aeruginosa. The results showed that a hormesis effect on growth at low doses of the single Phe (≤1 mg/L) or PAH mixtures (≤0.279 mg/L) was observed, whereas the single BaP induced significant growth inhibitions at all concentrations (≥0.2 mg/L). The median effective concentrations (96 h) for Phe, BaP and their mixtures were 4.29, 1.29 and 1.07 mg/L, respectively. Mixture toxicity models showed that Phe and BaP elicited a synergistic interaction on M. aeruginosa. The synergy may be ascribed to the excessive oxidative stress induced by PAH mixtures, which further led to membrane structure damages, photosynthesis inhibitions and decreased metabolic activity. Moreover, the microcystins (MCs) release significantly increased by 25.3% and 31.9% upon exposure to 0.558 and 1.116 mg/L of PAH mixtures. In all, this study suggested that the enhanced release of MCs by PAH mixtures might exacerbate potential risks to the aquatic environment.
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Affiliation(s)
- Xiang Wan
- School of Geography, School of Environment, Nanjing Normal University, Nanjing, 210023, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing, 210023, China
| | - Qingchun Guo
- School of Geography, School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Xiaojun Li
- School of Geography, School of Environment, Nanjing Normal University, Nanjing, 210023, China
| | - Guoxiang Wang
- School of Geography, School of Environment, Nanjing Normal University, Nanjing, 210023, China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing, 210023, China.
| | - Yanyan Zhao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
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64
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de Vries S, de Vries J. Evolutionary genomic insights into cyanobacterial symbioses in plants. QUANTITATIVE PLANT BIOLOGY 2022; 3:e16. [PMID: 37077989 PMCID: PMC10095879 DOI: 10.1017/qpb.2022.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 05/03/2023]
Abstract
Photosynthesis, the ability to fix atmospheric carbon dioxide, was acquired by eukaryotes through symbiosis: the plastids of plants and algae resulted from a cyanobacterial symbiosis that commenced more than 1.5 billion years ago and has chartered a unique evolutionary path. This resulted in the evolutionary origin of plants and algae. Some extant land plants have recruited additional biochemical aid from symbiotic cyanobacteria; these plants associate with filamentous cyanobacteria that fix atmospheric nitrogen. Examples of such interactions can be found in select species from across all major lineages of land plants. The recent rise in genomic and transcriptomic data has provided new insights into the molecular foundation of these interactions. Furthermore, the hornwort Anthoceros has emerged as a model system for the molecular biology of cyanobacteria-plant interactions. Here, we review these developments driven by high-throughput data and pinpoint their power to yield general patterns across these diverse symbioses.
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Affiliation(s)
- Sophie de Vries
- Department of Applied Bioinformatics, Institute for Microbiology and Genetics, University of Goettingen, Goettingen, Germany
- Authors for correspondence: Sophie de Vries E-mail: Jan de Vries E-mail:
| | - Jan de Vries
- Department of Applied Bioinformatics, Institute for Microbiology and Genetics, University of Goettingen, Goettingen, Germany
- Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
- Campus Institute Data Science (CIDAS), University of Goettingen, Goettingen, Germany
- Authors for correspondence: Sophie de Vries E-mail: Jan de Vries E-mail:
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Hu C, Zuo Y, Peng L, Gan N, Song L. Widespread Distribution and Adaptive Degradation of Microcystin Degrader ( mlr-Genotype) in Lake Taihu, China. Toxins (Basel) 2021; 13:toxins13120864. [PMID: 34941702 PMCID: PMC8705652 DOI: 10.3390/toxins13120864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 11/16/2022] Open
Abstract
Microbial degradation is an important route for removing environmental microcystins (MCs). Here, we investigated the ecological distribution of microcystin degraders (mlr-genotype), and the relationship between the substrate specificity of the microcystin degrader and the profile of microcystin congener production in the habitat. We showed that microcystin degraders were widely distributed and closely associated with Microcystis abundance in Lake Taihu, China. We characterized an indigenous degrader, Sphingopyxis N5 in the northern Lake Taihu, and it metabolized six microcystin congeners in increasing order (RR > LR > YR > LA > LF and LW). Such a substrate-specificity pattern was congruent to the order of the dominance levels of these congeners in northern Lake Taihu. Furthermore, a meta-analysis on global microcystin degraders revealed that the substrate-specificity patterns varied geographically, but generally matched the profiles of microcystin congener production in the degrader habitats, and the indigenous degrader typically metabolized well the dominant MC congeners, but not the rare congeners in the habitat. This highlighted the phenotypic congruence between microcystin production and degradation in natural environments. We theorize that such congruence resulted from the metabolic adaptation of the indigenous degrader to the local microcystin congeners. Under the nutrient microcystin selection, the degraders might have evolved to better exploit the locally dominant congeners. This study provided the novel insight into the ecological distribution and adaptive degradation of microcystin degraders.
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Affiliation(s)
- Chenlin Hu
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
- College of Pharmacy, University of Houston, Houston, TX 77204, USA
| | - Yanxia Zuo
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
| | - Liang Peng
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Nanqin Gan
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Correspondence: (N.G.); (L.S.)
| | - Lirong Song
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Correspondence: (N.G.); (L.S.)
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Wan Q, Li J, Chen Y. Comparative growth and cellular responses of toxigenic Microcystis exposed to different types of microplastics at various doses. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 290:117950. [PMID: 34419863 DOI: 10.1016/j.envpol.2021.117950] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/24/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Microplastics (MPs) pollution frequently co-occur with Microcystis-dominated blooms in freshwaters, but MPs effects on toxigenic Microcystis growth and effect mechanisms remained poorly understood. This study used 0.5 μm-size polyethylene (PE) and polyvinyl chloride (PVC) to explore dose- and time-dependent effects of single and combined MPs (i.e., PE + PVC) on toxigenic Microcystis growth and cellular responses during 16 day-test. Results showed that Microcystis growth and cellular responses depended on exposure time, MPs dose and type. MPs elicited hormesis effect in early stage at low dose (5 mg/L), while increasingly inhibited growth with rising PVC or PE + PVC dose but declining PE dose (5, 10, 50 mg/L) in mid-late stage, with stress intensity of PE + PVC > PVC > PE. Further analyses revealed unobvious cell damage under MPs stress, largely because antioxidases were increasingly activated as MPs stress enhanced. Unicellular MCs release ability during mid stage almost coincided with total/bound amount and each fraction of ex-poly and ex-pro trends under MPs stress. Significant positive relationship existed between MCs release ability and ex-poly/ex-pro fractions and total amount of Microcystis cells along mid-late stage under MPs stress, validating that ex-poly/ex-pro production was regulated as a result of MCs release. Besides, unicellular MCs production ability was generally positively correlated with soluble, tightly-bound and total ex-poly and ex-pro at late stage. These suggested that cellular antioxidants, MCs production/release ability and ex-poly/ex-pro production of Microcystis could be coupled to exert integrated defense against MPs stress to protect surviving cells in Microcystis population. These findings are crucial for acquiring the fate of Microcystis-dominated blooms co-occurring with MPs pollution, and reasonably assessing and managing involved eco-risks.
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Affiliation(s)
- Qianruo Wan
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, 100193, China
| | - Jieming Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, 100193, China.
| | - Yanran Chen
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, 100193, China
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67
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Kim M, Kim W, Lee Y, Park W. Linkage between bacterial community-mediated hydrogen peroxide detoxification and the growth of Microcystis aeruginosa. WATER RESEARCH 2021; 207:117784. [PMID: 34731663 DOI: 10.1016/j.watres.2021.117784] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/30/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Microcystis aeruginosa, an important cyanobloom-forming cyanobacterium, is sensitive to the high light intensity and consequent oxidative stress. Based on our genomic and transcriptomic analyses of H2O2-treated cells, many genes involved in photosynthesis, Calvin cycle, and microcystin synthesis were downregulated, whereas several toxin-antitoxin genes, DNA repair genes, and H2O2-defense systems such as peroxiredoxins and glutathione synthesis were upregulated. Axenic M. aeruginosa was then co-cultured with synthetic bacterial communities collected from 15 different freshwater samples with exhibiting different degrees of H2O2-production and catalase activities. Our analyses indicated that H2O2-resistant bacterial communities favored the growth and photosynthetic activity of M. aeruginosa cells under either H2O2 treatment or high light conditions. Nanopore-based bacterial community analyses indicated that these growth-promoting effects were likely attributable to a high proportion of Alphaproteobacteria (e.g., Brevundimonas and Ochrobactrum species), which protected M. aeruginosa cells from H2O2 toxicity. Further, these bacterial communities exhibited higher catalase activity levels and faster O2 production rates upon H2O2 detoxification. Taken together, our findings newly suggest that the occurrence of catalase-less M. aeruginosa blooms is largely influenced by the surrounding microbiota during high light and organic-rich conditions.
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Affiliation(s)
- Minkyung Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Yunho Lee
- Department of Food Science and Biotechnology, CHA University, Pocheon, Gyeonggi-do 11160, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea.
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68
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Genotyping and multivariate regression trees reveal ecological diversification within the Microcystis aeruginosa complex along a wide environmental gradient. Appl Environ Microbiol 2021; 88:e0147521. [PMID: 34818109 DOI: 10.1128/aem.01475-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Addressing the ecological and evolutionary processes underlying biodiversity patterns is essential to identify the mechanisms shaping community structure and function. In bacteria, the formation of new ecologically distinct populations (ecotypes) is proposed as one of the main drivers of diversification. New ecotypes arise when mutations in key functional genes or acquisition of new metabolic pathways by horizontal gene transfer allow the population to exploit new resources, permitting their coexistence with the parental population. We previously reported the presence of microcystin-producing organisms of the Microcystis aeruginosa complex (toxic MAC) through an 800 km environmental gradient ranging from freshwater to estuarine-marine waters in South America. We hypothesize that the success of toxic MAC in such a gradient is due to the existence of very closely related populations that are ecologically distinct (ecotypes), each specialized to a specific arrangement of environmental variables. Here, we analyzed toxic MAC genetic diversity through qPCR and high-resolution melting analysis (HRMA) of a functional gene (mcyJ, microcystin synthetase cluster). We explored the variability of the mcyJ gene along the environmental gradient by multivariate classification and regression trees (mCART). Six groups of mcyJ genotypes were distinguished and associated with different combinations of water temperature, conductivity and turbidity. We propose that each mcyJ variant associated to a defined environmental condition is an ecotype (or species) whose relative abundances vary according to their fitness in the local environment. This mechanism would explain the success of toxic MAC in such a wide array of environmental conditions. Importance Organisms of the Microcystis aeruginosa Complex form harmful algal blooms (HABs) in nutrient-rich water bodies worldwide. MAC HABs are difficult to manage owing to the production of potent toxins (microcystins) that resist water treatment. Besides, the role of microcystins in the ecology of MAC organisms is still elusive, meaning that the environmental conditions driving the toxicity of the bloom are not clear. Furthermore, the lack of coherence between morphology-based and genomic-based species classification makes it difficult to draw sound conclusions about when and where each member species of the MAC will dominate the bloom. Here, we propose that the diversification process and success of toxic MAC in a wide range of waterbodies involves the generation of ecotypes, each specialized in a particular niche, whose relative abundance varies according to its fitness in the local environment. This knowledge can improve the generation of accurate prediction models of MAC growth and toxicity, helping to prevent human and animal intoxication.
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69
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A Generic LC-HRMS Screening Method for Marine and Freshwater Phycotoxins in Fish, Shellfish, Water, and Supplements. Toxins (Basel) 2021; 13:toxins13110823. [PMID: 34822607 PMCID: PMC8619867 DOI: 10.3390/toxins13110823] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/17/2022] Open
Abstract
Phycotoxins occur in various marine and freshwater environments, and can accumulate in edible species such as fish, crabs, and shellfish. Human exposure to these toxins can take place, for instance, through consumption of contaminated species or supplements and through the ingestion of contaminated water. Symptoms of phycotoxin intoxication include paralysis, diarrhea, and amnesia. When the cause of an intoxication cannot directly be found, a screening method is required to identify the causative toxin. In this work, such a screening method was developed and validated for marine and freshwater phycotoxins in different matrices: fish, shellfish, water, and food supplements. Two LC methods were developed: one for hydrophilic and one for lipophilic phycotoxins. Sample extracts were measured in full scan mode with an Orbitrap high resolution mass spectrometer. Additionally, a database was created to process the data. The method was successfully validated for most matrices, and in addition, regulated lipophilic phycotoxins, domoic acid, and some paralytic shellfish poisoning toxins could be quantified in shellfish. The method showed limitations for hydrophilic phycotoxins in sea water and for lipophilic phycotoxins in food supplements. The developed method is a screening method; in order to confirm suspected compounds, comparison with a standard or an additional analysis such as NMR is required.
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70
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Menezes I, Capelo-Neto J, Pestana CJ, Clemente A, Hui J, Irvine JTS, Nimal Gunaratne HQ, Robertson PKJ, Edwards C, Gillanders RN, Turnbull GA, Lawton LA. Comparison of UV-A photolytic and UV/TiO 2 photocatalytic effects on Microcystis aeruginosa PCC7813 and four microcystin analogues: A pilot scale study. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 298:113519. [PMID: 34411798 DOI: 10.1016/j.jenvman.2021.113519] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 07/14/2021] [Accepted: 08/07/2021] [Indexed: 06/13/2023]
Abstract
To date, the high cost of supplying UV irradiation has prevented the widespread application of UV photolysis and titanium dioxide based photocatalysis in removing undesirable organics in the water treatment sector. To overcome this problem, the use of UV-LEDs (365 nm) for photolysis and heterogeneous photocatalysis applying TiO2 coated glass beads under UV-LED illumination (365 nm) in a pilot scale reactor for the elimination of Microcystis aeruginosa PCC7813 and four microcystin analogues (MC-LR, -LY, -LW, -LF) with a view to deployment in drinking water reservoirs was investigated. UV-A (365 nm) photolysis was shown to be more effective than the UV/TiO2 photocatalytic system for the removal of Microcystis aeruginosa cells and microcystins. During photolysis, cell density significantly decreased over 5 days from an initial concentration of 5.8 × 106 cells mL-1 until few cells were left. Both intra- and extracellular microcystin concentrations were significantly reduced by 100 and 92 %, respectively, by day 5 of the UV treatment for all microcystin analogues. During UV/TiO2 treatment, there was great variability between replicates, making prediction of the effect on cyanobacterial cell and toxin behavior difficult.
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Affiliation(s)
- Indira Menezes
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Brazil; School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom.
| | - José Capelo-Neto
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Brazil
| | - Carlos J Pestana
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Allan Clemente
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Brazil
| | - Jianing Hui
- School of Chemistry, University of St Andrews, St Andrews, United Kingdom
| | - John T S Irvine
- School of Chemistry, University of St Andrews, St Andrews, United Kingdom
| | - H Q Nimal Gunaratne
- School of Chemistry and Chemical Engineering, Queen's University, Belfast, United Kingdom
| | - Peter K J Robertson
- School of Chemistry and Chemical Engineering, Queen's University, Belfast, United Kingdom
| | - Christine Edwards
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Ross N Gillanders
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
| | - Graham A Turnbull
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
| | - Linda A Lawton
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
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71
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Wang K, Mou X, Cao H, Struewing I, Allen J, Lu J. Co-occurring microorganisms regulate the succession of cyanobacterial harmful algal blooms. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117682. [PMID: 34271516 PMCID: PMC8478823 DOI: 10.1016/j.envpol.2021.117682] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 06/10/2021] [Accepted: 06/28/2021] [Indexed: 05/04/2023]
Abstract
Cyanobacterial harmful algal blooms (CyanoHABs) have been found to transmit from N2 fixer-dominated to non-N2 fixer-dominated in many freshwater environments when the supply of N decreases. To elucidate the mechanisms underlying such "counter-intuitive" CyanoHAB species succession, metatranscriptomes (biotic data) and water quality-related variables (abiotic data) were analyzed weekly during a bloom season in Harsha Lake, a multipurpose lake that serves as a drinking water source and recreational ground. Our results showed that CyanoHABs in Harsha Lake started with N2-fixing Anabaena in June (ANA stage) when N was high, and transitioned to non-N2-fixing Microcystis- and Planktothrix-dominated in July (MIC-PLA stage) when N became limited (low TN/TP). Meanwhile, the concentrations of cyanotoxins, i.e., microcystins were significantly higher in the MIC-PLA stage. Water quality results revealed that N species (i.e., TN, TN/TP) and water temperature were significantly correlated with cyanobacterial biomass. Expression levels of several C- and N-processing-related cyanobacterial genes were highly predictive of the biomass of their species. More importantly, the biomasses of Microcystis and Planktothrix were also significantly associated with expressions of microbial genes (mostly from heterotrophic bacteria) related to processing organic substrates (alkaline phosphatase, peptidase, carbohydrate-active enzymes) and cyanophage genes. Collectively, our results suggest that besides environmental conditions and inherent traits of specific cyanobacterial species, the development and succession of CyanoHABs are regulated by co-occurring microorganisms. Specifically, the co-occurring microorganisms can alleviate the nutrient limitation of cyanobacteria by remineralizing organic compounds.
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Affiliation(s)
- Kai Wang
- Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Xiaozhen Mou
- Department of Biological Sciences, Kent State University, Kent, OH, United States
| | - Huansheng Cao
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, China
| | - Ian Struewing
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States
| | - Joel Allen
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States
| | - Jingrang Lu
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States.
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72
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Kibuye FA, Zamyadi A, Wert EC. A critical review on operation and performance of source water control strategies for cyanobacterial blooms: Part I-chemical control methods. HARMFUL ALGAE 2021; 109:102099. [PMID: 34815017 DOI: 10.1016/j.hal.2021.102099] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
Cyanobacterial blooms produce nuisance metabolites (e.g., cyanotoxins and T&O compounds) thereby posing water quality management issues for aquatic sources used for potable water production, aquaculture, and recreation. A variety of in-lake/reservoir control measures are implemented to reduce the abundance of nuisance cyanobacteria biomass or decrease the amount of available phosphorous (P). This paper critically reviews the chemical control strategies implemented for in-lake/reservoir management of cyanobacterial blooms, i.e., algaecides and nutrient sequestering coagulants/flocculants, by highlighting (i) their mode of action, (ii) cases of successful and unsuccessful treatment, (iii) and factors influencing performance (e.g., water quality, process control techniques, source water characteristics, etc.). Algaecides generally result in immediate improvements in water quality and offer selective cyanobacterial control when peroxide-based alagecides are used. However, they have a range of limitations: causing cell lysis and release of cyanotoxins, posing negative impacts on aquatic plants and animals, leaving behind environmentally relevant treatment residuals (e.g., Cu in water and sediments), and offering only short-term bloom control characterized by cyanobacterial rebound. Coagulants/flocculants (alum, iron, calcium, and lanthanum bentonite) offer long-term internal nutrient control when external nutrient loading is controlled. Treatment performance is often influenced by background water quality conditions, and source water characteristics (e.g., surface area, depth, mixing regimes, and residence time). The reviewed case studies highlight that external nutrient load reduction is the most fundamental aspect of cyanobacterial control. None of the reviewed control strategies provide a comprehensive solution to cyanobacterial blooms.
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Affiliation(s)
- Faith A Kibuye
- Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV 89193-9954, United States
| | - Arash Zamyadi
- Walter and Eliza Hall Institute of Medical Research (WEHI), 1G, Royal Parade, Parkville VIC 3052, Australia; Water Research Australia (WaterRA) Melbourne based position hosted by Melbourne Water, 990 La Trobe St, Docklands VIC 3008, Australia
| | - Eric C Wert
- Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV 89193-9954, United States.
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Huo D, Gan N, Geng R, Cao Q, Song L, Yu G, Li R. Cyanobacterial blooms in China: diversity, distribution, and cyanotoxins. HARMFUL ALGAE 2021; 109:102106. [PMID: 34815019 DOI: 10.1016/j.hal.2021.102106] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
Cyanobacterial blooms, which refer to the massive growth of harmful cyanobacteria, have altered the global freshwater ecosystems during the past decades. China has the largest population in the world, and it is suffering from the harmful effect of water eutrophication and cyanobacterial blooms along with rapid development of the economy and society. Research on cyanobacterial blooms and cyanotoxins in China have been overwhelmingly enhanced and emphasized during the past decades. In the present review, the research on cyanobacterial blooms in China is generally introduced, including the history of cyanobacterial bloom studies, the diversity of the bloom-forming cyanobacteria species (BFCS), and cyanotoxin studies in China. Most studies have focused on Microcystis, its blooms, and microcystins. Newly emerging blooms with the dominance of non-Microcystis BFCS have been gradually expanding to wide regions in China. Understanding the basic features of these non-Microcystis BFCS and their blooms, including their diversity, occurrence, physio-ecology, and harmful metabolites, will provide direction on future studies of cyanobacterial blooms in China.
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Affiliation(s)
- Da Huo
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Nanqin Gan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Ruozhen Geng
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 400049, PR China
| | - Qi Cao
- Tianjin Key Laboratory of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Lirong Song
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Gongliang Yu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Renhui Li
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou 325000, PR China.
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Tee HS, Wood SA, Bouma-Gregson K, Lear G, Handley KM. Genome Streamlining, Plasticity, and Metabolic Versatility Distinguish Co-occurring Toxic and Nontoxic Cyanobacterial Strains of Microcoleus. mBio 2021; 12:e0223521. [PMID: 34700377 PMCID: PMC8546630 DOI: 10.1128/mbio.02235-21] [Citation(s) in RCA: 6] [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: 07/27/2021] [Accepted: 09/20/2021] [Indexed: 01/21/2023] Open
Abstract
Harmful cyanobacterial bloom occurrences have increased worldwide due to climate change and eutrophication, causing nuisance and animal deaths. Species from the benthic cyanobacterial genus Microcoleus are ubiquitous and form thick mats in freshwater systems, such as rivers, that are sometimes toxic due to the production of potent neurotoxins (anatoxins). Anatoxin-producing (toxic) strains typically coexist with non-anatoxin-producing (nontoxic) strains in mats, although the reason for this is unclear. To determine the genetic mechanisms differentiating toxic and nontoxic Microcoleus, we sequenced and assembled genomes from 11 cultures and compared these to another 31 Microcoleus genomes. Average nucleotide identities (ANI) indicate that toxic and nontoxic strains are distinct species (ANI, <95%), and only 6% of genes are shared across all 42 genomes, suggesting a high level of genetic divergence among Microcoleus strains. Comparative genomics showed substantial genome streamlining in toxic strains and a potential dependency on external sources for thiamine and sucrose. Toxic and nontoxic strains are further differentiated by an additional set of putative nitrate transporter (nitrogen uptake) and cyanophycin (carbon and nitrogen storage) genes, respectively. These genes likely confer distinct competitive advantages based on nutrient availability and suggest nontoxic strains are more robust to nutrient fluctuations. Nontoxic strains also possess twice as many transposable elements, potentially facilitating greater genetic adaptation to environmental changes. Our results offer insights into the divergent evolution of Microcoleus strains and the potential for cooperative and competitive interactions that contribute to the co-occurrence of toxic and nontoxic species within mats. IMPORTANCE Microcoleus autumnalis, and closely related Microcoleus species, compose a geographically widespread group of freshwater benthic cyanobacteria. Canine deaths due to anatoxin-a poisoning, following exposure to toxic proliferations, have been reported globally. While Microcoleus proliferations are on the rise, the mechanisms underpinning competition between, or coexistence of, toxic and nontoxic strains are unknown. This study identifies substantial genetic differences between anatoxin-producing and non-anatoxin-producing strains, pointing to reduced metabolic flexibility in toxic strains, and potential dependence on cohabiting nontoxic strains. Results provide insights into the metabolic and evolutionary differences between toxic and nontoxic Microcoleus, which may assist in predicting and managing aquatic proliferations.
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Affiliation(s)
- Hwee Sze Tee
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | | | - Keith Bouma-Gregson
- U.S. Geological Survey, California Water Science Center, Sacramento, California, USA
| | - Gavin Lear
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Kim M. Handley
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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Li J, Cao L, Guo Z, An G, Li B, Li J. Time- and dose-dependent allelopathic effects and mechanisms of kaempferol on toxigenic Microcystis growth. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 222:112508. [PMID: 34284326 DOI: 10.1016/j.ecoenv.2021.112508] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
This study determined time-dependent IC50 and confirmed 3.5 mg/L as IC50 value for kaempferol inhibiting toxigenic Microcystis growth, based on which algicidal effects and mechanisms against toxigenic Microcystis exposed to various kaempferol doses (0.5-2 × IC50) were explored along 14 day-test. Results showed that growth inhibition ratio (GIR) almost elevated with increasing kaempferol dose, and at each dose GIR elevated firstly and fluctuated around 17.8%- > 40%, 53.6%-65.6% and 84.8%-89.3% at 1.75, 3.5 and 7 mg/L kaempferol during mid-late stage, respectively. With rising kaempferol dose, photosynthetic pigments contents (chlorophyll-a, phycobiliproteins), antioxidant response (superoxide dismutase and catalase (CAT) activities, glutathione (GSH) contents) and microcystins (MCs) production were almost increasingly stimulated as cellular protective responses during early-mid stage. However, these parameters (excluding CAT and GSH) were almost increasingly inhibited at late stage by prolonged stress and Microcystis cell was still more severely damaged as dose elevated along test, which could be reasons for increasing GIR with rising kamepferol dose. Persistent stimulation of CAT and GSH at each dose could alleviate cell damage until late stage, thus GIR no longer increased at late stage at each kaempferol dose. Moreover, fewer MCs release under kaempferol stress than control suggested kaempferol as eco-safe algaecide for migrating toxigenic Microcystis-dominated blooms (MCBs) and decreasing MCs risks. Compared with our previous data for luteolin inhibiting toxigenic Microcystis, this study supported formerly-proposed 'flavonoids structure - algicidal activity' relationship that the only OH-location difference between kaempferol and luteolin could affect algicidal activity and mechanisms against toxigenic Microcystis. Also, kaempferol and luteolin was revealed to exert additive effect on toxigenic Microcystis growth at equitoxic ratio. Our findings gave novel algicidal scenario of flavonoids and were greatly implicated in eco-friendly migrating toxigenic MCBs.
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Affiliation(s)
- Jieming Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Linrong Cao
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Zhonghui Guo
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Guangqi An
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Biying Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Ji Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China.
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Vilar MCP, da Costa Pena Rodrigues TF, da Silva Ferrão-Filho A, de Oliveira E Azevedo SMF. Grazer-Induced Chemical Defense in a Microcystin-Producing Microcystis aeruginosa (Cyanobacteria) Exposed to Daphnia gessneri Infochemicals. J Chem Ecol 2021; 47:847-858. [PMID: 34569003 DOI: 10.1007/s10886-021-01315-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
Cyanobacteria are photosynthetic microorganisms that compose phytoplankton and therefore have a trophic relationship with zooplankton, which represent an important link for energy flux in aquatic food webs. Several species can form blooms and produce bioactive metabolites known as cyanotoxins. However, the ecological and adaptative role of these toxins are still under debate. Many studies have addressed the cyanotoxins' function in defense against herbivory when grazing pressure by zooplankton plays a role in phytoplankton top-down control. Thus, the present study evaluated the ecophysiological responses of the cyanobacterial strain Microcystis aeruginosa NPLJ-4 underlying the chemical induced defense against the cladoceran Daphnia gessneri. Exposure to predator infochemicals consisted of cultures established in ASM-1 medium prepared in a filtrate from a culture of adults of D. gessneri at an environmentally relevant density. Daphnia infochemicals promoted a significant increase in toxin production by M. aeruginosa. However, no differences in growth were observed, despite a significant increase in both maximum photosynthetic efficiency and electron transport rate in response to zooplankton. Additionally, there was no significant variation in the production of exopolysaccharides. Overall, although a grazer-induced defense response was demonstrated, there were no effects on M. aeruginosa fitness, which maintained its growth in the presence of Daphnia alarm cues.
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Affiliation(s)
- Mauro Cesar Palmeira Vilar
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, 21949-902, Brazil.
| | - Thiago Ferreira da Costa Pena Rodrigues
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, 21949-902, Brazil
| | - Aloysio da Silva Ferrão-Filho
- Laboratory of Evaluation and Promotion of Environmental Health, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, 21040-360, Brazil
| | - Sandra Maria Feliciano de Oliveira E Azevedo
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, 21949-902, Brazil
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Li B, Li J, An G, Zhao C, Wang C. Long-term and strong suppression against Microcystis growth and microcystin-release by luteolin continuous-release microsphere: Optimal construction, characterization, effects and proteomic mechanisms. WATER RESEARCH 2021; 202:117448. [PMID: 34364065 DOI: 10.1016/j.watres.2021.117448] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/21/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
Microcystis-dominated cyanobacterial blooms (MCBs) severely threaten ecological health by causing hypoxia and releasing microcystins (MCs). Luteolin has potential as low-cost eco-safe algaecide against Microcystis, but to enhance sustainability of its algicidal effect and elucidate underlying mechanisms at proteomic level are urgently desirable. This study optimally constructed continuous-release microsphere (CRM) of luteolin with strong solidity and durability even after long-term immersion. Applying luteolin CRM, this study developed a long-term algicidal option to strongly inhibit Microcystis growth and MC-release until 49 days, with inhibition ratios of growth and MC-release (both ≥ 98%) and inhibitory effect-lasting time (nearly 50 days) of CRM superior to most former reports, and long-term strong inhibitory effects of CRM on Microcystis growth and MC-release kept stable at various nitrogen levels. Also, luteolin CRM rendered extracellular MCs content decrease to nearby acceptable threshold for drinking water. These signified a promising prospect of luteolin CRM in sustained effective control against toxigenic MCBs in waters of different eutrophic states. Comparative proteomic analysis showed that luteolin CRM significantly up-regulated photosynthesis and protein homestasis, but down-regulated other processes including stress response, MC-synthesis/release, glycolysis, amino acid synthesis, fatty acid synthesis/β-oxidation, tricarboxylic acid cycle, transcription, translation, transport, cell shaping and cell division. These implied that continuous stress of luteolin released from CRM induced Microcystis proteome towards a shift of higher energy storage but lower energy release/consumption, which largely disturbed its physiological metabolic processes and thus negatively impact its growth. Proteomics results shed newly deep insights on algicidal mechanisms of flavonoid in the form of CRM.
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Affiliation(s)
- Biying Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Jieming Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China.
| | - Guangqi An
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Caihong Zhao
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Chengyu Wang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
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Tazart Z, Manganelli M, Scardala S, Buratti FM, Nigro Di Gregorio F, Douma M, Mouhri K, Testai E, Loudiki M. Remediation Strategies to Control Toxic Cyanobacterial Blooms: Effects of Macrophyte Aqueous Extracts on Microcystis aeruginosa (Growth, Toxin Production and Oxidative Stress Response) and on Bacterial Ectoenzymatic Activities. Microorganisms 2021; 9:microorganisms9081782. [PMID: 34442861 PMCID: PMC8400474 DOI: 10.3390/microorganisms9081782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
Increasing toxic cyanobacterial blooms in freshwater demand environmentally friendly solutions to control their growth and toxicity, especially in arid countries, where most drinking water is produced from surface reservoirs. We tested the effects of macrophyte allelochemicals on Microcystis aeruginosa and on the fundamental role of bacteria in nutrient recycling. The effects of Ranunculus aquatilis aqueous extract, the most bioactive of four Moroccan macrophyte extracts, were tested in batch systems on M. aeruginosa growth, toxin production and oxidative stress response and on the ectoenzymatic activity associated with the bacterial community. M. aeruginosa density was reduced by 82.18%, and a significant increase in oxidative stress markers was evidenced in cyanobacterial cells. Microcystin concentration significantly decreased, and they were detected only intracellularly, an important aspect in managing toxic blooms. R. aquatilis extract had no negative effects on associated bacteria. These results confirm a promising use of macrophyte extracts, but they cannot be generalized. The use of the extract on other toxic strains, such as Planktothrix rubescens, Raphidiopsis raciborskii and Chrysosporum ovalisporum, caused a reduction in growth rate but not in cyanotoxin content, increasing toxicity. The need to assess species-specific cyanobacteria responses to verify the efficacy and safety of the extracts for human health and the environment is highlighted.
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Affiliation(s)
- Zakaria Tazart
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
- Water, Biodiversity and Climate Change Laboratory, Phycology, Biotechnology and Environmental Toxicology Research Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah P.O. Box 2390, Marrakech 40000, Morocco; (K.M.); (M.L.)
| | - Maura Manganelli
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
- Correspondence:
| | - Simona Scardala
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Franca Maria Buratti
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Federica Nigro Di Gregorio
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Mountasser Douma
- Environmental Microbiology and Toxicology Research Unit, Polydisciplinary Faculty of Khouribga (FPK), Sultan Moulay Slimane University, Beni Mellal 23000, Morocco;
| | - Khadija Mouhri
- Water, Biodiversity and Climate Change Laboratory, Phycology, Biotechnology and Environmental Toxicology Research Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah P.O. Box 2390, Marrakech 40000, Morocco; (K.M.); (M.L.)
| | - Emanuela Testai
- Istituto Superiore di Sanità, Environment & Health Department, Viale Regina Elena, 299, 00161 Rome, Italy; (Z.T.); (S.S.); (F.M.B.); (F.N.D.G.); (E.T.)
| | - Mohammed Loudiki
- Water, Biodiversity and Climate Change Laboratory, Phycology, Biotechnology and Environmental Toxicology Research Unit, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah P.O. Box 2390, Marrakech 40000, Morocco; (K.M.); (M.L.)
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Markandran K, Xuan JVLE, Yu H, Shun LM, Ferenczi MA. Mn 2+ -Phos-Tag Polyacrylamide for the Quantification of Protein Phosphorylation Levels. Curr Protoc 2021; 1:e221. [PMID: 34411463 DOI: 10.1002/cpz1.221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This paper provides a guideline for optimizing and utilizing Mn2+ Phos-tag gel technology to separate phosphorylated proteins from their unphosphorylated counterparts. It provides key insights into methods for careful sample preparation and experimental directions for determining the appropriate Phos-tag gel compositions and electrophoresis and western blotting conditions. This protocol has been used to successfully resolve proteins extracted from cardiac and skeletal muscles. The guidelines can be extended for optimizing protocols to resolve proteins from other cells or tissue sources. With this, phosphoproteomics and the elucidation of underlying mechanisms of disease progression can be accelerated. © 2021 The Authors. Current Protocols published by Wiley Periodicals LLC.
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Affiliation(s)
- Kasturi Markandran
- Laboratory of Muscle and Cardiac Biophysics, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Jane Vanetta Lee En Xuan
- Laboratory of Muscle and Cardiac Biophysics, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Haiyang Yu
- Laboratory of Muscle and Cardiac Biophysics, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,WuXi Biologics, Wuxi, Jiangsu, China
| | - Lim Meng Shun
- Laboratory of Muscle and Cardiac Biophysics, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Michael A Ferenczi
- Laboratory of Muscle and Cardiac Biophysics, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Brunel Medical School, Brunel University London, Uxbridge, UK
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Tian H, Jin J, Chen B, Lefebvre DD, Lougheed SC, Wang Y. Depth-Dependent Spatiotemporal Dynamics of Overwintering Pelagic Microcystis in a Temperate Water Body. Microorganisms 2021; 9:microorganisms9081718. [PMID: 34442797 PMCID: PMC8399979 DOI: 10.3390/microorganisms9081718] [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: 07/09/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 12/03/2022] Open
Abstract
Cyanobacteria in the genus Microcystis are dominant components of many harmful algal blooms worldwide. Their pelagic–benthic life cycle helps them survive periods of adverse conditions and contributes greatly to their ecological success. Many studies on Microcystis overwintering have focused on benthic colonies and suggest that sediment serves as the major inoculum for subsequent summer blooms. However, the contemporaneous overwintering pelagic population may be important as well but is understudied. In this study, we investigated near-surface and near-bottom pelagic population dynamics of both microcystin-producing Microcystis and total Microcystis over six weeks in winter at Dog Lake (South Frontenac, ON, Canada). We quantified relative Microcystis concentrations using real-time PCR. Our results showed that the spatiotemporal distribution of overwintering pelagic Microcystis was depth dependent. The abundance of near-bottom pelagic Microcystis declined with increased depth with no influence of depth on near-surface Microcystis abundance. In the shallow region of the lake (<10 m), most pelagic Microcystis was found near the lake bottom (>90%). However, the proportion of near-surface Microcystis rose sharply to over 60% as the depth increased to approximately 18 m. The depth-dependent distribution pattern was found to be similar in both microcystin-producing Microcystis and total Microcystis. Our results suggest the top of the water column may be a more significant contributor of Microcystis recruitment inoculum than previously thought and merits more attention in early CHAB characterization and remediation.
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Affiliation(s)
- Haolun Tian
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (H.T.); (J.J.); (D.D.L.); (S.C.L.)
| | - Junjie Jin
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (H.T.); (J.J.); (D.D.L.); (S.C.L.)
| | - Bojian Chen
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;
| | - Daniel D. Lefebvre
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (H.T.); (J.J.); (D.D.L.); (S.C.L.)
| | - Stephen C. Lougheed
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (H.T.); (J.J.); (D.D.L.); (S.C.L.)
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;
| | - Yuxiang Wang
- Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada; (H.T.); (J.J.); (D.D.L.); (S.C.L.)
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China;
- Correspondence:
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81
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Wang K, Mou X. Coordinated Diel Gene Expression of Cyanobacteria and Their Microbiome. Microorganisms 2021; 9:microorganisms9081670. [PMID: 34442749 PMCID: PMC8398468 DOI: 10.3390/microorganisms9081670] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022] Open
Abstract
Diel rhythms have been well recognized in cyanobacterial metabolisms. However, whether this programmed activity of cyanobacteria could elicit coordinated diel gene expressions in microorganisms (microbiome) that co-occur with cyanobacteria and how such responses in turn impact cyanobacterial metabolism are unknown. To address these questions, a microcosm experiment was set up using Lake Erie water to compare the metatranscriptomic variations of Microcystis cells alone, the microbiome alone, and these two together (whole water) over two day-night cycles. A total of 1205 Microcystis genes and 4779 microbiome genes exhibited significant diel expression patterns in the whole-water microcosm. However, when Microcystis and the microbiome were separated, only 515 Microcystis genes showed diel expression patterns. A significant structural change was not observed for the microbiome communities between the whole-water and microbiome microcosms. Correlation analyses further showed that diel expressions of carbon, nitrogen, phosphorous, and micronutrient (iron and vitamin B12) metabolizing genes were significantly coordinated between Microcystis and the microbiome in the whole-water microcosm. Our results suggest that diel fluxes of organic carbon and vitamin B12 (cobalamin) in Microcystis could cause the diel expression of microbiome genes. Meanwhile, the microbiome communities may support the growth of Microcystis by supplying them with recycled nutrients, but compete with Microcystis for iron.
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Omidi A, Pflugmacher S, Kaplan A, Kim YJ, Esterhuizen M. Reviewing Interspecies Interactions as a Driving Force Affecting the Community Structure in Lakes via Cyanotoxins. Microorganisms 2021; 9:1583. [PMID: 34442662 PMCID: PMC8401979 DOI: 10.3390/microorganisms9081583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 11/26/2022] Open
Abstract
The escalating occurrence of toxic cyanobacterial blooms worldwide is a matter of concern. Global warming and eutrophication play a major role in the regularity of cyanobacterial blooms, which has noticeably shifted towards the predomination of toxic populations. Therefore, understanding the effects of cyanobacterial toxins in aquatic ecosystems and their advantages to the producers are of growing interest. In this paper, the current literature is critically reviewed to provide further insights into the ecological contribution of cyanotoxins in the variation of the lake community diversity and structure through interspecies interplay. The most commonly detected and studied cyanobacterial toxins, namely the microcystins, anatoxins, saxitoxins, cylindrospermopsins and β-N-methylamino-L-alanine, and their ecotoxicity on various trophic levels are discussed. This work addresses the environmental characterization of pure toxins, toxin-containing crude extracts and filtrates of single and mixed cultures in interspecies interactions by inducing different physiological and metabolic responses. More data on these interactions under natural conditions and laboratory-based studies using direct co-cultivation approaches will provide more substantial information on the consequences of cyanotoxins in the natural ecosystem. This review is beneficial for understanding cyanotoxin-mediated interspecies interactions, developing bloom mitigation technologies and robustly assessing the hazards posed by toxin-producing cyanobacteria to humans and other organisms.
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Affiliation(s)
- Azam Omidi
- Chair Ecological Impact Research and Ecotoxicology, Technische Universität Berlin, 10587 Berlin, Germany;
| | - Stephan Pflugmacher
- Clayton H. Riddell Faculty of Environment, Earth, and Resources, University of Manitoba, Wallace Bldg., 125 Dysart Rd, Winnipeg, MB R3T 2N2, Canada;
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel;
| | - Young Jun Kim
- Joint Laboratory of Applied Ecotoxicology, Korean Institute of Science and Technology Europe (KIST), Campus 7.1, 66123 Saarbrücken, Germany;
| | - Maranda Esterhuizen
- Joint Laboratory of Applied Ecotoxicology, Korean Institute of Science and Technology Europe (KIST), Campus 7.1, 66123 Saarbrücken, Germany;
- Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Niemenkatu 73, 15140 Lahti, Finland
- Finland and Helsinki Institute of Sustainability Science (HELSUS), Fabianinkatu 33, 00014 Helsinki, Finland
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83
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Morón-Asensio R, Schuler D, Wiedlroither A, Offterdinger M, Kurmayer R. Differential Labeling of Chemically Modified Peptides and Lipids among Cyanobacteria Planktothrix and Microcystis. Microorganisms 2021; 9:1578. [PMID: 34442657 PMCID: PMC8398151 DOI: 10.3390/microorganisms9081578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/18/2021] [Accepted: 07/19/2021] [Indexed: 11/20/2022] Open
Abstract
The cyanoHAB forming cyanobacteria Microcystis and Planktothrix frequently produce high intracellular amounts of microcystins (MCs) or anabaenopeptins (APs). In this study, chemically modified MCs and APs have been localized on a subcellular level in Microcystis and Planktothrix applying copper-catalyzed alkyne-azide cycloaddition (CuACC). For this purpose, three different non-natural amino acids carrying alkyne or azide moieties were fed to individual P. agardhii strains No371/1 and CYA126/8 as well as to M. aeruginosa strain Hofbauer showing promiscuous incorporation of various amino acid substrates during non-ribosomal peptide synthesis (NRPS). Moreover, CYA126/8 peptide knock-out mutants and non-toxic strain Synechocystis PCC6803 were processed under identical conditions. Simultaneous labeling of modified peptides with ALEXA405 and ALEXA488 and lipid staining with BODIPY 505/515 were performed to investigate the intracellular location of the modified peptides. Pearson correlation coefficients (PCC) obtained from confocal images were calculated between the different fluorophores and the natural autofluorescence (AF), and between labeled modified peptides and dyed lipids to investigate the spatial overlap between peptides and the photosynthetic complex, and between peptides and lipids. Overall, labeling of modified MCs (M. aeruginosa) and APs (P. agardhii) using both fluorophores revealed increased intensity in MC/AP producing strains. For Synechocystis lacking NRPS, no labeling using either ALEXA405 or ALEXA488 was observed. Lipid staining in M. aeruginosa and Synechocystis was intense while in Planktothrix it was more variable. When compared with AF, both modified peptides and lipids showed a heterologous distribution. In comparison, the correlation between stained lipids and labeled peptides was not increased suggesting a reduced spatial overlap.
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Affiliation(s)
- Rubén Morón-Asensio
- Research Department for Limnology, University of Innsbruck, Mondseestrasse 9, 5310 Mondsee, Austria; (D.S.); (A.W.)
| | - David Schuler
- Research Department for Limnology, University of Innsbruck, Mondseestrasse 9, 5310 Mondsee, Austria; (D.S.); (A.W.)
| | - Anneliese Wiedlroither
- Research Department for Limnology, University of Innsbruck, Mondseestrasse 9, 5310 Mondsee, Austria; (D.S.); (A.W.)
| | - Martin Offterdinger
- Core Facility Biooptics (CCB), Medical University Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria;
| | - Rainer Kurmayer
- Research Department for Limnology, University of Innsbruck, Mondseestrasse 9, 5310 Mondsee, Austria; (D.S.); (A.W.)
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84
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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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85
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Otogo RA, Chia MA, Uyovbisere EE, Iortsuun DN, Bittencourt-Oliveira MDC. Effect of ultraviolet radiation (type B) and titanium dioxide nanoparticles on the interspecific interaction between Microcystis flos-aquae and Pseudokirchneriella subcapitata. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 779:146561. [PMID: 34030274 DOI: 10.1016/j.scitotenv.2021.146561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 03/11/2021] [Accepted: 03/14/2021] [Indexed: 06/12/2023]
Abstract
Anthropogenic activities have led to the depletion of the ultraviolet radiation screening ozone layer, exposing aquatic biota to its harmful effects. Also, the rising applications of nanotechnology are resulting in the release and contamination of aquatic ecosystems with engineered nanometals like titanium dioxide nanoparticles (nTiO2). The rise in ultraviolet radiation interacts with nanometals, increasing their bioactivities to susceptible aquatic organisms such as algae and cyanobacteria. The effect of ultraviolet radiation B (UVB) and nTiO2 on Microcystis flos-aquae and Pseudokirchneriella subcapitata during inter-specific interaction was investigated. The specific growth rate (d-1) of M. flos-aquae exposed to nTiO2 increased significantly under monoculture conditions but was suppressed during co-culture with P. subcapitata. Contrarily, UVB stimulated the growth of the cyanobacterium regardless of the presence or absence of the green microalgae. However, there was a general decline in the growth of P. subcapitata following cultivation with M. flos-aquae and exposure to UVB and nTiO2. The chlorophyll-a and total chlorophyll content of the monocultures of M. flos-aquae exposed to nTiO2 increased while other co-culture treatments significantly decreased these parameters. The experimental treatments, UVB, nTiO2, and UVB + nTiO2 had differential effects on the pigment content of P. subcapitata. The total protein content, intracellular H2O2, peroxidase (POD), and glutathione S-transferase (GST) activity of both M. flos-aquae and P. subcapitata increased at varying degrees as a function of the treatment condition. Microcystin content was highest in co-cultures exposed to UVB. The results of this study suggest that increasing levels of nTiO2 and UVB significantly alter the growth and cellular metabolic activity of M. flos-aquae and P. subcapitata, but the cyanobacterium will probably be favored by increasing UVB levels and its interaction with nanometals like nTiO2 in aquatic ecosystems.
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Affiliation(s)
| | | | | | | | - Maria do Carmo Bittencourt-Oliveira
- Department of Biological Sciences, Luiz de Queiroz College of Agriculture, University of São Paulo, Av. Pádua Dias, 11, São Dimas, 13418-900 Piracicaba, SP, Brazil
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86
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Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806. Microorganisms 2021; 9:microorganisms9061265. [PMID: 34200971 PMCID: PMC8230624 DOI: 10.3390/microorganisms9061265] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 12/02/2022] Open
Abstract
The ubiquitous freshwater cyanobacterium Microcystis is remarkably successful, showing a high tolerance against fluctuations in environmental conditions. It frequently forms dense blooms which can accumulate significant amounts of the hepatotoxin microcystin, which plays an extracellular role as an infochemical but also acts intracellularly by interacting with proteins of the carbon metabolism, notably with the CO2 fixing enzyme RubisCO. Here we demonstrate a direct link between external microcystin and its intracellular targets. Monitoring liquid cultures of Microcystis in a diel experiment revealed fluctuations in the extracellular microcystin content that correlate with an increase in the binding of microcystin to intracellular proteins. Concomitantly, reversible relocation of RubisCO from the cytoplasm to the cell’s periphery was observed. These variations in RubisCO localization were especially pronounced with cultures grown at higher cell densities. We replicated these effects by adding microcystin externally to cultures grown under continuous light. Thus, we propose that microcystin may be part of a fast response to conditions of high light and low carbon that contribute to the metabolic flexibility and the success of Microcystis in the field.
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87
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Dick GJ, Duhaime MB, Evans JT, Errera RM, Godwin CM, Kharbush JJ, Nitschky HS, Powers MA, Vanderploeg HA, Schmidt KC, Smith DJ, Yancey CE, Zwiers CC, Denef VJ. The genetic and ecophysiological diversity of Microcystis. Environ Microbiol 2021; 23:7278-7313. [PMID: 34056822 DOI: 10.1111/1462-2920.15615] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/24/2021] [Accepted: 05/27/2021] [Indexed: 01/30/2023]
Abstract
Microcystis is a cyanobacterium that forms toxic blooms in freshwater ecosystems around the world. Biological variation among taxa within the genus is apparent through genetic and phenotypic differences between strains and via the spatial and temporal distribution of strains in the environment, and this fine-scale diversity exerts strong influence over bloom toxicity. Yet we do not know how varying traits of Microcystis strains govern their environmental distribution, the tradeoffs and links between these traits, or how they are encoded at the genomic level. Here we synthesize current knowledge on the importance of diversity within Microcystis and on the genes and traits that likely underpin ecological differentiation of taxa. We briefly review spatial and environmental patterns of Microcystis diversity in the field and genetic evidence for cohesive groups within Microcystis. We then compile data on strain-level diversity regarding growth responses to environmental conditions and explore evidence for variation of community interactions across Microcystis strains. Potential links and tradeoffs between traits are identified and discussed. The resulting picture, while incomplete, highlights key knowledge gaps that need to be filled to enable new models for predicting strain-level dynamics, which influence the development, toxicity and cosmopolitan nature of Microcystis blooms.
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Affiliation(s)
- Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Melissa B Duhaime
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Jacob T Evans
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Reagan M Errera
- National Oceanographic and Atmospheric Administration Great Lakes Environmental Research Lab, Ann Arbor, MI, USA
| | - Casey M Godwin
- School for Environment and Sustainability, Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, MI, USA
| | - Jenan J Kharbush
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Helena S Nitschky
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - McKenzie A Powers
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Henry A Vanderploeg
- National Oceanographic and Atmospheric Administration Great Lakes Environmental Research Lab, Ann Arbor, MI, USA
| | - Kathryn C Schmidt
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Derek J Smith
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Colleen E Yancey
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Claire C Zwiers
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Vincent J Denef
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
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88
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Depth profiles of protein-bound microcystin in Küçükçekmece Lagoon. Toxicon 2021; 198:156-163. [PMID: 33992691 DOI: 10.1016/j.toxicon.2021.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/17/2021] [Accepted: 05/10/2021] [Indexed: 11/20/2022]
Abstract
Microcystis is the most commonly found toxic cyanobacterial genus around the world and has a negative impact on the ecosystem. As a predominant producer of the potent hepatotoxin microcystin (MC), the genus causes outbreaks in freshwaters worldwide. Standard analytical methods that are used for the detection of microcystin variants can only measure the free form of microcystin in cells. Since microcystin was found as free and protein-bound forms in the cells, a significant proportion of microcystin is underestimated with analytical methods. The aim of the study was to measure protein-bound microcystins and determine the environmental factors that affect the binding of microcystin to proteins. Samples were taken at depths of surface, 1 m, 5 m, 10 m, 15 m, and 18 m in Küçükçekmece Lagoon to analyze depth profiles of two different microcystin forms from June to September 2012 at regular monthly intervals. Our findings suggest that the most important parameter affecting protein-bound microcystin at surface water is high light. Due to favorable environmental conditions such as temperature, light, and physicochemical parameters, the higher microcystin contents, both free and protein-bound MCs, were found in summer periods.
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89
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90
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Lage S, Mazur-Marzec H, Gorokhova E. Competitive interactions as a mechanism for chemical diversity maintenance in Nodularia spumigena. Sci Rep 2021; 11:8970. [PMID: 33903638 PMCID: PMC8076297 DOI: 10.1038/s41598-021-88361-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023] Open
Abstract
Nodularia spumigena is a bloom-forming diazotrophic cyanobacterium inhabiting brackish waters worldwide. This species produces non-ribosomal peptides (NRPs), including the hepatotoxin nodularin, often referred to as cyanotoxin. Several known classes of NRPs have various biological activities, although their modes of action are poorly understood. In the Baltic N. spumigena, there is a high NRP chemodiversity among strains, allowing their grouping in specific chemotypes and subgroups. Therefore, it is relevant to ask whether the NRP production is affected by intraspecific interactions between the co-existing strains. Using a novel approach that combines culture technique and liquid chromatography-tandem mass spectrometry for the NRP analysis, we examined N. spumigena strains under mono- and co-culture conditions. The test strains were selected to represent N. spumigena belonging to the same or different chemotype subgroups. In this setup, we observed physiological and metabolic responses in the test strains grown without cell contact. The changes in NRP levels to co-culture conditions were conserved within a chemotype subgroup but different between the subgroups. Our results suggest that intraspecific interactions may promote a chemical diversity in N. spumigena population, with higher NRP production compared to a single-strain population. Studying allelochemical signalling in this cyanobacterium is crucial for understanding toxicity mechanisms and plankton community interactions in the Baltic Sea and other aquatic systems experiencing regular blooms.
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Affiliation(s)
- Sandra Lage
- grid.10548.380000 0004 1936 9377Department of Environmental Science, Stockholm University, Stockholm, Sweden ,grid.8585.00000 0001 2370 4076Division of Marine Biotechnology, Institute of Oceanography, University of Gdańsk, Gdynia, Poland
| | - Hanna Mazur-Marzec
- grid.8585.00000 0001 2370 4076Division of Marine Biotechnology, Institute of Oceanography, University of Gdańsk, Gdynia, Poland
| | - Elena Gorokhova
- grid.10548.380000 0004 1936 9377Department of Environmental Science, Stockholm University, Stockholm, Sweden
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91
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Jacinavicius FR, Geraldes V, Crnkovic CM, Delbaje E, Fiore MF, Pinto E. Effect of ultraviolet radiation on the metabolomic profiles of potentially toxic cyanobacteria. FEMS Microbiol Ecol 2021; 97:6006873. [PMID: 33242088 DOI: 10.1093/femsec/fiaa243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 11/24/2020] [Indexed: 11/13/2022] Open
Abstract
Interactions between climate change and ultraviolet radiation (UVR) have a substantial impact on aquatic ecosystems, especially on photosynthetic organisms. To counteract the damaging effects of UVR, cyanobacteria developed adaptive strategies such as the biosynthesis of secondary metabolites. This study aimed to evaluate the effects of UVR on the metabolomic profiles of potentially toxic cyanobacteria. Twelve strains were irradiated with ultraviolet A and ultraviolet B radiation and parabolic aluminized reflector lamps for 3 days, followed by liquid chromatography-tandem mass spectometry (LC-MS/MS) analysis to assess changes in metabolomic profiles. Matrices were used to generate principal component analysis biplots, and molecular networks were obtained using the Global Natural Products platform. Most strains showed significant changes in their metabolomic profiles after UVR exposure. On average, 7% of MS features were shown to be exclusive to metabolomic profiles before UVR exposure, while 9% were unique to metabolomic profiles after UVR exposure. The identified compounds included aeruginosins, spumigins, cyanopeptolins, microginins, namalides, pseudospumigins, anabaenopeptins, mycosporine-like amino acids, nodularins and microcystins. Data showed that cyanobacteria display broad metabolic plasticity upon UVR exposure, including the synthesis and differential expression of a variety of secondary metabolites. This could result in a competitive advantage, supporting cyanobacterial blooms under various UVR light exposures.
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Affiliation(s)
| | - Vanessa Geraldes
- University of São Paulo, School of Pharmaceutical Sciences, São Paulo-SP, Brazil
| | - Camila M Crnkovic
- University of São Paulo, School of Pharmaceutical Sciences, São Paulo-SP, Brazil
| | - Endrews Delbaje
- University of São Paulo, Centre for Nuclear Energy in Agriculture, Piracicaba-SP, Brazil
| | - Marli F Fiore
- University of São Paulo, Centre for Nuclear Energy in Agriculture, Piracicaba-SP, Brazil
| | - Ernani Pinto
- University of São Paulo, School of Pharmaceutical Sciences, São Paulo-SP, Brazil.,University of São Paulo, Centre for Nuclear Energy in Agriculture, Piracicaba-SP, Brazil
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92
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Wu D, Wang T, Wang J, Jiang L, Yin Y, Guo H. Size-dependent toxic effects of polystyrene microplastic exposure on Microcystis aeruginosa growth and microcystin production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143265. [PMID: 33257060 DOI: 10.1016/j.scitotenv.2020.143265] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/10/2020] [Accepted: 10/22/2020] [Indexed: 06/12/2023]
Abstract
Due to increasingly severe microplastic pollution in freshwaters, the interaction between these contaminants and cyanobacteria warrants study. In this study, we expose the freshwater cyanobacterium Microcystis aeruginosa to different sizes (1 μm and 100 nm) of polystyrene (PS) microplastics of 5 mg/L. Results indicate 1 μm microplastics promote algal growth (12.42% ± 0.94%) at 96 h, and have greater potential to aggregate on algal cell surfaces and inhibit photosynthesis. But no significance was observed in 100 nm microplastics treatment on algal growth and photosynthetic activity after 96 h exposure. Especially, 1 μm microplastics increased the content of intracellular microcystins (MCs) (18.42% ±0.33%) after 72 h and inhibit MCs release (23.87% ±8.79%) at 72 h, while 100 nm PS microplastics promote MCs production only at 48 h (14.83% ± 7.07%). Results indicate that smaller size does not necessarily mean greater toxicity, 1 μm microplastics showing more adverse effects than 100 nm microplastics to M. aeruginosa, improving understanding of the toxicity of microplastics in freshwater ecosystems, and challenging the conventionally held belief that smaller microplastics are more toxic.
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Affiliation(s)
- Di Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Ting Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Jing Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Lijuan Jiang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Ying Yin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
| | - Hongyan Guo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
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93
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Larsen JS, Pearson LA, Neilan BA. Genome Mining and Evolutionary Analysis Reveal Diverse Type III Polyketide Synthase Pathways in Cyanobacteria. Genome Biol Evol 2021; 13:6178795. [PMID: 33739400 PMCID: PMC8086630 DOI: 10.1093/gbe/evab056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2021] [Indexed: 11/30/2022] Open
Abstract
Cyanobacteria are prolific producers of natural products, including polyketides and hybrid compounds thereof. Type III polyketide synthases (PKSs) are of particular interest, due to their wide substrate specificity and simple reaction mechanism, compared with both type I and type II PKSs. Surprisingly, only two type III PKS products, hierridins, and (7.7)paracyclophanes, have been isolated from cyanobacteria. Here, we report the mining of 517 cyanobacterial genomes for type III PKS biosynthesis gene clusters. Approximately 17% of the genomes analyzed encoded one or more type III PKSs. Together with already characterized type III PKSs, the phylogeny of this group of enzymes was investigated. Our analysis showed that type III PKSs in cyanobacteria evolved into three major lineages, including enzymes associated with 1) (7.7)paracyclophane-like biosynthesis gene clusters, 2) hierridin-like biosynthesis gene clusters, and 3) cytochrome b5 genes. The evolutionary history of these enzymes is complex, with some sequences partitioning primarily according to speciation and others putatively according to their reaction type. Protein modeling showed that cyanobacterial type III PKSs generally have a smaller active site cavity (mean = 109.035 Å3) compared with enzymes from other organisms. The size of the active site did not correlate well with substrate size, however, the “Gatekeeper” amino acid residues within the active site were strongly correlated to enzyme phylogeny. Our study provides unprecedented insight into the distribution, diversity, and molecular evolution of cyanobacterial type III PKSs, which could facilitate the discovery, characterization, and exploitation of novel enzymes, biochemical pathways, and specialized metabolites from this biosynthetically talented clade of microorganisms.
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Affiliation(s)
- Joachim Steen Larsen
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, New South Wales, Australia
| | - Leanne Andrea Pearson
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, New South Wales, Australia
| | - Brett Anthony Neilan
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, New South Wales, Australia
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94
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Jiang Y, Liu Y, Zhang J. Mechanisms for the stimulatory effects of a five-component mixture of antibiotics in Microcystis aeruginosa at transcriptomic and proteomic levels. JOURNAL OF HAZARDOUS MATERIALS 2021; 406:124722. [PMID: 33296757 DOI: 10.1016/j.jhazmat.2020.124722] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/16/2020] [Accepted: 11/26/2020] [Indexed: 06/12/2023]
Abstract
Antibiotic contaminants could promote the formation of harmful cyanobacterial blooms through hormetic stimulation, but the mechanisms underlying these stimulatory effects remain unclear. This study investigated the biochemical, transcriptomic, and proteomic responses of a dominant bloom-forming cyanobacterium, Microcystis aeruginosa, to a five-component mixture of frequently detected antibiotics at current contamination levels. The growth rate of M. aeruginosa presented a U-shaped dose-response to 50-500 ng L-1 of mixed antibiotics. Alterations in the transcriptome of M. aeruginosa suggested the excitation of both photosynthesis and carbon metabolism, increasing energy generation in response to oxidative stress induced by low-dose antibiotics, and thus contributing to the significant (p < 0.05) increase in growth rate, Fv/Fm, and cell density. Comparison between transcriptomic and proteomic responses further confirmed the action mode of the mixed antibiotics. Proteins and their corresponding genes related to ROS scavenging, photosynthesis, carbon fixation, electron transport, oxidative phosphorylation, and biosynthesis, showed consistent expression tendencies in response to 200 ng L-1 of mixed antibiotics, which were credible action targets of mixed antibiotics in M. aeruginosa. Mixed antibiotics stimulated microcystin synthesis by upregulating a microcystin synthetase and its encoding gene (mcyC), which could increase the hazard of M. aeruginosa in aquatic environments.
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Affiliation(s)
- Yunhan Jiang
- 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
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95
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Weenink EFJ, Matthijs HCP, Schuurmans JM, Piel T, van Herk MJ, Sigon CAM, Visser PM, Huisman J. Interspecific protection against oxidative stress: green algae protect harmful cyanobacteria against hydrogen peroxide. Environ Microbiol 2021; 23:2404-2419. [PMID: 33587811 PMCID: PMC8248038 DOI: 10.1111/1462-2920.15429] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 02/08/2021] [Indexed: 11/27/2022]
Abstract
Oceanographic studies have shown that heterotrophic bacteria can protect marine cyanobacteria against oxidative stress caused by hydrogen peroxide (H2O2). Could a similar interspecific protection play a role in freshwater ecosystems? In a series of laboratory experiments and two lake treatments, we demonstrate that freshwater cyanobacteria are sensitive to H2O2 but can be protected by less‐sensitive species such as green algae. Our laboratory results show that green algae degrade H2O2 much faster than cyanobacteria. Consequently, the cyanobacterium Microcystis was able to survive at higher H2O2 concentrations in mixtures with the green alga Chlorella than in monoculture. Interestingly, even the lysate of destructed Chlorella was capable to protect Microcystis, indicating a two‐component H2O2 degradation system in which Chlorella provided antioxidant enzymes and Microcystis the reductants. The level of interspecific protection provided to Microcystis depended on the density of Chlorella. These findings have implications for the mitigation of toxic cyanobacterial blooms, which threaten the water quality of many eutrophic lakes and reservoirs worldwide. In several lakes, H2O2 has been successfully applied to suppress cyanobacterial blooms. Our results demonstrate that high densities of green algae can interfere with these lake treatments, as they may rapidly degrade the added H2O2 and thereby protect the bloom‐forming cyanobacteria.
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Affiliation(s)
- Erik F J Weenink
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
| | - Hans C P Matthijs
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
| | - J Merijn Schuurmans
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
| | - Tim Piel
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
| | - Maria J van Herk
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
| | - Corrien A M Sigon
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
| | - Petra M Visser
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, Amsterdam, GE, 1090, The Netherlands
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96
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Ma J, Wang P. Effects of rising atmospheric CO 2 levels on physiological response of cyanobacteria and cyanobacterial bloom development: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:141889. [PMID: 32920383 DOI: 10.1016/j.scitotenv.2020.141889] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/15/2020] [Accepted: 08/20/2020] [Indexed: 05/19/2023]
Abstract
Increasing atmospheric CO2 concentration negatively impacts aquatic ecosystems and may exacerbate the problem of undesirable cyanobacterial bloom development in freshwater ecosystems. Elevated levels of atmospheric CO2 may increase the levels of dissolved CO2 in freshwater systems, via air-water exchanges, enhancing primary production in the water and catchments. Although high CO2 levels improve cyanobacterial growth and increase cyanobacterial biomass, the impacts on their internal physiological processes can be more complex. Here, we have reviewed previous studies to evaluate the physiological responses of cyanobacteria to high concentrations of CO2. In response to high CO2 concentrations, the pressures of inorganic carbon absorption are reduced, and carbon concentration mechanisms are downregulated, affecting the intracellular metabolic processes and competitiveness of the cyanobacteria. Nitrogen and phosphorus metabolism and light utilization are closely related to CO2 assimilation, and these processes are likely to be affected by resource and energy reallocation when CO2 levels are high. Additionally, the responses of diazotrophic and toxic cyanobacteria to elevated CO2 levels were specifically reviewed. The responses of diazotrophic cyanobacteria to elevated CO2 concentrations were found to be inconsistent, probably because of differences in other factors in experimental designs. Toxic cyanobacteria tended to be superior to non-toxic strains at low levels of CO2; however, the specific effects of microcystin on the regulation require further investigation. Furthermore, the effects of increasing CO2 levels on cyanobacterial competitiveness in phytoplankton communities and nutrient cycling in aquatic ecosystems were reviewed. High CO2 concentrations may make cyanobacteria less competitive relative to other algal taxa; however, due to the complexity of natural systems and the specificity of algal species, the dominant positions of the cyanobacteria do not seems to be changed. To better understand cyanobacterial responses to elevated CO2 levels and help control cyanobacterial bloom developments, this review has identified key areas for future research.
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Affiliation(s)
- Jingjie Ma
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, People's Republic of China; College of Environment, Hohai University, Nanjing 210098, People's Republic of China.
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97
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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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98
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Pappas D, Panou M, Adamakis IDS, Gkelis S, Panteris E. Beyond Microcystins: Cyanobacterial Extracts Induce Cytoskeletal Alterations in Rice Root Cells. Int J Mol Sci 2020; 21:ijms21249649. [PMID: 33348912 PMCID: PMC7766381 DOI: 10.3390/ijms21249649] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/09/2020] [Accepted: 12/15/2020] [Indexed: 12/15/2022] Open
Abstract
Microcystins (MCs) are cyanobacterial toxins and potent inhibitors of protein phosphatases 1 (PP1) and 2A (PP2A), which are involved in plant cytoskeleton (microtubules and F-actin) organization. Therefore, studies on the toxicity of cyanobacterial products on plant cells have so far been focused on MCs. In this study, we investigated the effects of extracts from 16 (4 MC-producing and 12 non-MC-producing) cyanobacterial strains from several habitats, on various enzymes (PP1, trypsin, elastase), on the plant cytoskeleton and H2O2 levels in Oryza sativa (rice) root cells. Seedling roots were treated for various time periods (1, 12, and 24 h) with aqueous cyanobacterial extracts and underwent either immunostaining for α-tubulin or staining of F-actin with fluorescent phalloidin. 2,7-dichlorofluorescein diacetate (DCF-DA) staining was performed for H2O2 imaging. The enzyme assays confirmed the bioactivity of the extracts of not only MC-rich (MC+), but also MC-devoid (MC−) extracts, which induced major time-dependent alterations on both components of the plant cytoskeleton. These findings suggest that a broad spectrum of bioactive cyanobacterial compounds, apart from MCs or other known cyanotoxins (such as cylindrospermopsin), can affect plants by disrupting the cytoskeleton.
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Affiliation(s)
- Dimitris Pappas
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (M.P.); (S.G.)
- Correspondence: (D.P.); (E.P.); Tel.: +30-2310-998908 (E.P.)
| | - Manthos Panou
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (M.P.); (S.G.)
| | | | - Spyros Gkelis
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (M.P.); (S.G.)
| | - Emmanuel Panteris
- Department of Botany, School of Biology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (M.P.); (S.G.)
- Correspondence: (D.P.); (E.P.); Tel.: +30-2310-998908 (E.P.)
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99
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Wan X, Steinman AD, Gu Y, Zhu G, Shu X, Xue Q, Zou W, Xie L. Occurrence and risk assessment of microcystin and its relationship with environmental factors in lakes of the eastern plain ecoregion, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:45095-45107. [PMID: 32779064 DOI: 10.1007/s11356-020-10384-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
The frequent occurrence of microcystins (MCs) in freshwater poses serious threats to the drinking water safety and health of human beings. Although MCs have been detected in individual fresh waters in China, little is known about their occurrence over a large geographic scale. An investigation of 30 subtropical lakes in eastern China was performed during summer 2018 to determine the MCs concentrations in water and their possible risk via direct water consumption to humans, and to assess the associated environmental factors. MCs were detected in 28 of 30 lakes, and the highest mean MCs concentrations occurred in Lake Chaohu (26.7 μg/L), followed by Lake Taihu (3.11 μg/L). MC-LR was the primary variant observed in our study, and MCs were mainly produced by Microcystis, Anabaena (Dolicospermum), and Oscillatoria in these lakes. Replete nitrogen and phosphorus concentrations, irradiance, and stable water column conditions were critical for dominance of MC-producing cyanobacteria and high MCs production in our study. Hazard quotients indicated that human health risk of MCs in most lakes was at moderate or low levels except Lakes Chaohu and Taihu. Nutrient control management is recommended to decrease the likelihood of high MCs production. Finally, we recommend the regional scale thresholds of total nitrogen and total phosphorus concentrations of 1.19 mg/L and 7.14 × 10-2 mg/L, respectively, based on the drinking water guideline of MC-LR (1 μg/L) recommended by World Health Organization. These targets for nutrient control will aid water quality managers to reduce human health risks created by exposure to MCs.
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Affiliation(s)
- Xiang Wan
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Alan D Steinman
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI, 49441, USA
| | - Yurong Gu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guangwei Zhu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Xiubo Shu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Qingju Xue
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Wei Zou
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liqiang Xie
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
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100
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Pestana CJ, Portela Noronha J, Hui J, Edwards C, Gunaratne HQN, Irvine JTS, Robertson PKJ, Capelo-Neto J, Lawton LA. Photocatalytic removal of the cyanobacterium Microcystis aeruginosa PCC7813 and four microcystins by TiO 2 coated porous glass beads with UV-LED irradiation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 745:141154. [PMID: 32758751 DOI: 10.1016/j.scitotenv.2020.141154] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/22/2020] [Accepted: 07/19/2020] [Indexed: 06/11/2023]
Abstract
Cyanobacteria and their toxic secondary metabolites are a challenge in water treatment due to increased biomass and dissolved metabolites in the raw water. Retrofitting existing water treatment infrastructure is prohibitively expensive or unfeasible, hence 'in-reservoir' treatment options are being explored. In the current study, a treatment system was able to photocatalytically inhibit the growth of Microcystis aeruginosa and remove released microcystins by photocatalysis using titanium dioxide coated, porous foamed glass beads and UV-LEDs (365 nm). A 35% reduction of M. aeruginosa PCC7813 cell density compared to control samples was achieved in seven days. As a function of cell removal, intracellular microcystins (microcystin-LR, -LY, -LW, and -LF) were removed by 49% from 0.69 to 0.35 μg mL-1 in seven days. Microcystins that leaked into the surrounding water from compromised cells were completely removed by photocatalysis. The findings of the current study demonstrate the feasibility of an in-reservoir treatment unit applying low cost UV-LEDs and porous foamed beads made from recycled glass coated with titanium dioxide as a means to control cyanobacteria and their toxins before they can reach the water treatment plant.
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Affiliation(s)
- Carlos J Pestana
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom.
| | - Jolita Portela Noronha
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom; Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Brazil
| | - Jianing Hui
- School of Chemistry, University of St. Andrews, St. Andrews, United Kingdom
| | - Christine Edwards
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - H Q Nimal Gunaratne
- School of Chemistry and Chemical Engineering, Queen's University, Belfast, United Kingdom
| | - John T S Irvine
- School of Chemistry, University of St. Andrews, St. Andrews, United Kingdom
| | - Peter K J Robertson
- School of Chemistry and Chemical Engineering, Queen's University, Belfast, United Kingdom
| | - José Capelo-Neto
- Department of Hydraulic and Environmental Engineering, Federal University of Ceará, Fortaleza, Brazil
| | - Linda A Lawton
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
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