E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Cyanobacteria and Cyanotoxins: New Advances and Future Challenges"

A special issue of Toxins (ISSN 2072-6651). This special issue belongs to the section "Marine and Freshwater Toxins".

Deadline for manuscript submissions: closed (31 May 2018)

Special Issue Editors

Guest Editor
Prof. Ana M. Cameán

University of Sevilla (Spain), Department of Food Science, Toxicology and Legal Medicine, Faculty of Pharmacy, Sevilla 41012, Sevilla, Spain
E-Mail
Guest Editor
Prof. Angeles Jos

University of Sevilla (Spain), Department of Food Science, Toxicology and Legal Medicine, Faculty of Pharmacy, Sevilla 41012, Sevilla, Spain
E-Mail

Special Issue Information

Dear Colleauges,

Cyanobacteria are a group of ubiquitous photosynthetic procariota. Their occurrence is increasing around the world, due to anthropogenic activities and climate changes. Several cyanobacterial species are able to synthesize a high number of bioactive molecules, among them, cyanotoxins (microcystins, cylindrospermopsin, nodularin, etc.), which are considered a health concern. For risk asessment of cyanotoxins, more scientific knowledge is required to perform an adequate hazard characterization, exposure evaluation and, finally, risk characterization of these toxins. This Special Issue, “Cyanobacteria and Cyanotoxins: New Advances and Future Changelles”, is addressed to gather new research or review articles related to different aspects of cyanobacteria and cyanotoxins, such as new advances and tools for sampling and monitoring of blooms, analytical determination of cyanotoxins in different matrices, such as water, food, soil and biological samples, water treatment methods, remediation approaches, toxicological evaluation including in vitro and in vivo studies of toxic mechanisms at molecular level, search of biomarkers, etc. Special interest is focused on research on multitoxins as most of the data refer to individual cyanotoxins, although co-ocurrence of different toxins or variants has been demonstrated. Similarly, the possibility of interactions with other contaminants will be taken into account, as recommended by international organisms. Moreover, studies of other new bioactive compounds from cyanobacteria are welcome.

Prof. Ana M. Cameán
Prof. Angeles Jos
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a double-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxins is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Cyanobacteria, cyanotoxins
  • occurrence
  • risk assessment
  • toxicity
  • analytical determination
  • bioactive molecules

Published Papers (13 papers)

View options order results:
result details:
Displaying articles 1-13
Export citation of selected articles as:

Research

Jump to: Review

Open AccessFeature PaperArticle New Method for Simultaneous Determination of Microcystins and Cylindrospermopsin in Vegetable Matrices by SPE-UPLC-MS/MS
Toxins 2018, 10(10), 406; https://doi.org/10.3390/toxins10100406
Received: 7 September 2018 / Revised: 3 October 2018 / Accepted: 6 October 2018 / Published: 8 October 2018
PDF Full-text (1709 KB) | HTML Full-text | XML Full-text
Abstract
Cyanotoxins are a large group of noxious metabolites with different chemical structure and mechanisms of action, with a worldwide distribution, producing effects in animals, humans, and crop plants. When cyanotoxin-contaminated waters are used for the irrigation of edible vegetables, humans can be in
[...] Read more.
Cyanotoxins are a large group of noxious metabolites with different chemical structure and mechanisms of action, with a worldwide distribution, producing effects in animals, humans, and crop plants. When cyanotoxin-contaminated waters are used for the irrigation of edible vegetables, humans can be in contact with these toxins through the food chain. In this work, a method for the simultaneous detection of Microcystin-LR (MC-LR), Microcystin-RR (MC-RR), Microcystin-YR (MC-YR), and Cylindrospermopsin (CYN) in lettuce has been optimized and validated, using a dual solid phase extraction (SPE) system for toxin extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for analysis. Results showed linear ranges (5–50 ng g−1 f.w.), low values for limit of detection (LOD) (0.06–0.42 ng g−1 f.w.), and limit of quantification (LOQ) (0.16–0.91 ng g−1 f.w.), acceptable recoveries (41–93%), and %RSDIP values for the four toxins. The method proved to be robust for the three variables tested. Finally, it was successfully applied to detect these cyanotoxins in edible vegetables exposed to cyanobacterial extracts under laboratory conditions, and it could be useful for monitoring these toxins in edible vegetables for better exposure estimation in terms of risk assessment. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle Histopathological Evaluation of the Exposure by Cyanobacteria Cultive Containing [d-Leu1]Microcystin-LR on Lithobates catesbeianus Tadpoles
Received: 11 June 2018 / Revised: 21 July 2018 / Accepted: 24 July 2018 / Published: 6 August 2018
PDF Full-text (2697 KB) | HTML Full-text | XML Full-text
Abstract
This study evaluated the effects of [d-Leu1]Microcystin-LR variant by the exposure of Lithobates catesbeianus tadpole to unialgal culture Microcystis aeruginosa NPLJ-4 strain. The Tadpole was placed in aquariums and exposed to Microcystis aeruginosa culture or disrupted cells. For 16
[...] Read more.
This study evaluated the effects of [d-Leu1]Microcystin-LR variant by the exposure of Lithobates catesbeianus tadpole to unialgal culture Microcystis aeruginosa NPLJ-4 strain. The Tadpole was placed in aquariums and exposed to Microcystis aeruginosa culture or disrupted cells. For 16 days, 5 individuals were removed every 2 days, and tissue samples of liver, skeletal muscle, and intestinal tract were collected for histopathology and bioaccumulation analyses. After exposure, those surviving tadpoles were placed in clean water for 15 days to evaluate their recovery. A control without algae and toxins was maintained in the same conditions and exhibited normal histology and no tissue damage. In exposed tadpoles, samples were characterized by serious damages that similarly affected the different organs, such as loss of adhesion between cells, nucleus fragmentation, necrosis, and hemorrhage. Samples showed signs of recovery but severe damages were still observed. Neither HPLC-PDA nor mass spectrometry analysis showed any evidence of free Microcystins bioaccumulation. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle Variations of Bacterial Community Composition and Functions in an Estuary Reservoir during Spring and Summer Alternation
Received: 18 July 2018 / Revised: 31 July 2018 / Accepted: 3 August 2018 / Published: 6 August 2018
PDF Full-text (4686 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In this study, we focused on the dynamics of bacterial community composition in a large reservoir in the Yangtze estuary during spring and summer seasons, especially the variations of functional mechanisms of microbial community during the seasonal alternation between spring and summer. Both
[...] Read more.
In this study, we focused on the dynamics of bacterial community composition in a large reservoir in the Yangtze estuary during spring and summer seasons, especially the variations of functional mechanisms of microbial community during the seasonal alternation between spring and summer. Both 16S rRNA gene sequencing and shotgun metagenomic sequencing technology were used for these purposes. The results indicated that obvious variations of bacterial community structures were found at different sites. Particle-associated bacterial taxa exhibited higher abundance at the inlet site, which was closer to the Yangtze River with a high level of turbidity. In other sites, Synechococcus, as the most dominant cyanobacterial species, revealed high abundance driven by increased temperature. Moreover, some heterotrophic bacterial taxa revealed high abundance following the increased Synechococcus in summer, which indicated potential correlations about carbon source utilization between these microorganisms. In addition, the shotgun metagenomic data indicated during the period of seasonal alternation between spring and summer, the carbohydrate transport and metabolism, energy production and conversion, translation/ribosomal biogenesis, and cell wall/membrane/envelope biogenesis were significantly enhanced at the exit site. However, the course of cell cycle control/division was more active at the internal site. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessFeature PaperArticle Differential Toxicity of Cyanobacteria Isolated from Marine Sponges towards Echinoderms and Crustaceans
Received: 28 May 2018 / Revised: 15 July 2018 / Accepted: 16 July 2018 / Published: 18 July 2018
PDF Full-text (1653 KB) | HTML Full-text | XML Full-text
Abstract
Marine sponges and cyanobacteria have a long history of co-evolution, with documented genome adaptations in cyanobionts. Both organisms are known to produce a wide variety of natural compounds, with only scarce information about novel natural compounds produced by cyanobionts. In the present study,
[...] Read more.
Marine sponges and cyanobacteria have a long history of co-evolution, with documented genome adaptations in cyanobionts. Both organisms are known to produce a wide variety of natural compounds, with only scarce information about novel natural compounds produced by cyanobionts. In the present study, we aimed to address their toxicological potential, isolating cyanobacteria (n = 12) from different sponge species from the coast of Portugal (mainland, Azores, and Madeira Islands). After large-scale growth, we obtained both organic and aqueous extracts to perform a series of ecologically-relevant bioassays. In the acute toxicity assay, using nauplii of Artemia salina, only organic extracts showed lethality, especially in picocyanobacterial strains. In the bioassay with Paracentrotus lividus, both organic and aqueous extracts produced embryogenic toxicity (respectively 58% and 36%), pointing to the presence of compounds that interfere with growth factors on cells. No development of pluteus larvae was observed for the organic extract of the strain Chroococcales 6MA13ti, indicating the presence of compounds that affect skeleton formation. In the hemolytic assay, none of the extracts induced red blood cells lysis. Organic extracts, especially from picoplanktonic strains, proved to be the most promising for future bioassay-guided fractionation and compounds isolation. This approach allows us to classify the compounds extracted from the cyanobacteria into effect categories and bioactivity profiles. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle Multi-Toxin Occurrences in Ten French Water Resource Reservoirs
Received: 31 May 2018 / Revised: 28 June 2018 / Accepted: 2 July 2018 / Published: 9 July 2018
PDF Full-text (1450 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Cyanobacteria are known to produce a wide array of metabolites, including various classes of toxins. Among these, hepatotoxins (Microcystins), neurotoxins (Anatoxin-A and PSP toxins) or cytotoxins (Cylindrospermopsins) have been subjected to numerous, individual studies during the past twenty years. Reports of toxins co-occurrences,
[...] Read more.
Cyanobacteria are known to produce a wide array of metabolites, including various classes of toxins. Among these, hepatotoxins (Microcystins), neurotoxins (Anatoxin-A and PSP toxins) or cytotoxins (Cylindrospermopsins) have been subjected to numerous, individual studies during the past twenty years. Reports of toxins co-occurrences, however, remain scarce in the literature. The present work is an inventory of cyanobacteria with a particular focus on Nostocales and their associated toxin classes from 2007 to 2010 in ten lakes used for drinking water production in France. The results show that potential multiple toxin producing species are commonly encountered in cyanobacteria populations. Individual toxin classes were detected in 75% of all samples. Toxin co-occurrences appeared in 40% of samples as two- or three-toxin combinations (with 35% for the microcystins–anatoxin combination), whereas four-toxin class combinations only appeared in 1% of samples. Toxin co-occurrences could be partially correlated to species composition and water temperature. Peak concentrations however could never be observed simultaneously and followed distinct, asymmetrical distribution patterns. As observations are the key for preventive management and risk assessment, these results indicate that water monitoring should search for all four toxin classes simultaneously instead of focusing on the most frequent toxins, i.e., microcystins. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle Effects of Dietary Astaxanthin Supplementation on Energy Budget and Bioaccumulation in Procambarus clarkii (Girard, 1852) Crayfish under Microcystin-LR Stress
Received: 7 May 2018 / Revised: 19 June 2018 / Accepted: 21 June 2018 / Published: 4 July 2018
PDF Full-text (532 KB) | HTML Full-text | XML Full-text
Abstract
This research aimed to study the effects of astaxanthin on energy budget and bioaccumulation of microcystin-leucine-arginine (microcystin-LR) in the crayfish Procambarus clarkii (Girard, 1852). The crayfish (21.13 ± 4.6 g) were cultured under microcystin-LR stress (0.025 mg/L) and were fed with fodders containing
[...] Read more.
This research aimed to study the effects of astaxanthin on energy budget and bioaccumulation of microcystin-leucine-arginine (microcystin-LR) in the crayfish Procambarus clarkii (Girard, 1852). The crayfish (21.13 ± 4.6 g) were cultured under microcystin-LR stress (0.025 mg/L) and were fed with fodders containing astaxanthin (0, 3, 6, 9, and 12 mg/g) for 8 weeks in glass tanks (350 mm × 450 mm × 150 mm). Accumulations of microcystin-LR were measured in different organs of P. clarkii. The results suggested that astaxanthin can significantly improve the survival rate and specific growth rate (SGR) of P. clarkii (p < 0.05). The dietary astaxanthin supplement seems to block the bioaccumulation of microcystin-LR in the hepatopancreas and ovaries of P. clarkii to some extent (p < 0.05). Astaxanthin content of 9–12 mg/g in fodder can be a practical and economic choice. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health
Received: 10 May 2018 / Revised: 19 June 2018 / Accepted: 21 June 2018 / Published: 3 July 2018
PDF Full-text (2925 KB) | HTML Full-text | XML Full-text
Abstract
The presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on
[...] Read more.
The presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on the phylogenetic analysis of the 16S rRNA gene. Bottom sediment samples were collected from selected rivers: Limpopo, Crocodile, Mokolo, Mogalakwena, Nzhelele, Lephalale, Sand Rivers (South Africa); Notwane (Botswana); and Shashe River and Mzingwane River (Zimbabwe). A physical-chemical analysis of the bottom sediments showed the availability of nutrients, nitrates and phosphates, in excess of 0.5 mg/L, in most of the river sediments, while alkalinity, pH and salinity were in excess of 500 mg/L. The FlowCam showed the dominant cyanobacteria species that were identified from the sediment samples, and these were the Microcystis species, followed by Raphidiopsis raciborskii, Phormidium and Planktothrix species. The latter species were also confirmed by molecular techniques. Nevertheless, two samples showed an amplification of the cylindrospermopsin polyketide synthetase gene (S3 and S9), while the other two samples showed an amplification for the microcystin/nodularin synthetase genes (S8 and S13). Thus, these findings may imply the presence of toxic cyanobacteria species in the studied river sediments. The presence of cyanobacteria may be hazardous to humans because rural communities and farmers abstract water from the Limpopo river catchment for human consumption, livestock and wildlife watering and irrigation. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle Development of Time-Resolved Fluoroimmunoassay for Detection of Cylindrospermopsin Using Its Novel Monoclonal Antibodies
Received: 29 May 2018 / Revised: 13 June 2018 / Accepted: 15 June 2018 / Published: 21 June 2018
PDF Full-text (1139 KB) | HTML Full-text | XML Full-text
Abstract
Cylindrospermopsin (CYN) is a cyanotoxin that is of particular concern for its potential toxicity to human and animal health and ecological consequences due to contamination of drinking water. The increasing emergence of CYN around the world has led to urgent development of rapid
[...] Read more.
Cylindrospermopsin (CYN) is a cyanotoxin that is of particular concern for its potential toxicity to human and animal health and ecological consequences due to contamination of drinking water. The increasing emergence of CYN around the world has led to urgent development of rapid and high-throughput methods for its detection in water. In this study, a highly sensitive monoclonal antibody N8 was produced and characterized for CYN detection through the development of a direct competitive time-resolved fluorescence immunoassay (TRFIA). The newly developed TRFIA exhibited a typical sigmoidal response for CYN at concentrations of 0.01–100 ng mL−1, with a wide quantitative range between 0.1 and 50 ng mL−1. The detection limit of the method was calculated to be 0.02 ng mL−1, which is well below the guideline value of 1 μg L−1 and is sensitive enough to provide an early warning of the occurrence of CYN-producing cyanobacterial blooms. The newly developed TRFIA also displayed good precision and accuracy, as evidenced by low coefficients of variation (4.1–6.5%). Recoveries ranging from 92.6% to 108.8% were observed upon the analysis of CYN-spiked water samples. Moreover, comparison of the TRIFA with an ELISA kit through testing 76 water samples and 15 Cylindrospermopsis cultures yielded a correlation r2 value of 0.963, implying that the novel immunoassay was reliable for the detection of CYN in water and algal samples. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Graphical abstract

Open AccessArticle Resveratrol Ameliorates Microcystin-LR-Induced Testis Germ Cell Apoptosis in Rats via SIRT1 Signaling Pathway Activation
Received: 22 May 2018 / Revised: 3 June 2018 / Accepted: 5 June 2018 / Published: 9 June 2018
Cited by 1 | PDF Full-text (3752 KB) | HTML Full-text | XML Full-text
Abstract
Microcystin-leucine arginine (MC-LR), a cyclic heptapeptide produced by cyanobacteria, is a strong reproductive toxin. Studies performed in rat Sertoli cells and Chinese hamster ovary cells have demonstrated typical apoptosis after MC-LR exposure. However, little is known on how to protect against the reproductive
[...] Read more.
Microcystin-leucine arginine (MC-LR), a cyclic heptapeptide produced by cyanobacteria, is a strong reproductive toxin. Studies performed in rat Sertoli cells and Chinese hamster ovary cells have demonstrated typical apoptosis after MC-LR exposure. However, little is known on how to protect against the reproductive toxicity induced by MC-LR. The present study aimed to explore the possible molecular mechanism underlying the anti-apoptosis and protective effects of resveratrol (RES) on the co-culture of Sertoli–germ cells and rat testes. The results demonstrated that MC-LR treatment inhibited the proliferation of Sertoli–germ cells and induced apoptosis. Furthermore, sirtuin 1 (SIRT1) and Bcl-2 were inhibited, while p53 and Ku70 acetylation, Bax expression, and cleaved caspase-3 were upregulated by MC-LR. However, RES pretreatment ameliorated MC-LR-induced apoptosis and SIRT1 inhibition, and downregulated the MC-LR-induced increase in p53 and Ku70 acetylation, Bax expression, and caspase-3 activation. In addition, RES reversed the MC-LR-mediated reduction in Ku70 binding to Bax. The present study indicated that the administration of RES could ameliorate MC-LR-induced Sertoli–germ cell apoptosis and protect against reproductive toxicity in rats by stimulating the SIRT1/p53 pathway, suppressing p53 and Ku70 acetylation and enhancing the binding of Ku70 to Bax. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle Toxic Cyanobacteria in Svalbard: Chemical Diversity of Microcystins Detected Using a Liquid Chromatography Mass Spectrometry Precursor Ion Screening Method
Received: 9 February 2018 / Revised: 27 March 2018 / Accepted: 29 March 2018 / Published: 3 April 2018
Cited by 1 | PDF Full-text (1564 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Cyanobacteria synthesize a large variety of secondary metabolites including toxins. Microcystins (MCs) with hepato- and neurotoxic potential are well studied in bloom-forming planktonic species of temperate and tropical regions. Cyanobacterial biofilms thriving in the polar regions have recently emerged as a rich source
[...] Read more.
Cyanobacteria synthesize a large variety of secondary metabolites including toxins. Microcystins (MCs) with hepato- and neurotoxic potential are well studied in bloom-forming planktonic species of temperate and tropical regions. Cyanobacterial biofilms thriving in the polar regions have recently emerged as a rich source for cyanobacterial secondary metabolites including previously undescribed congeners of microcystin. However, detection and detailed identification of these compounds is difficult due to unusual sample matrices and structural congeners produced. We here report a time-efficient liquid chromatography-mass spectrometry (LC-MS) precursor ion screening method that facilitates microcystin detection and identification. We applied this method to detect six different MC congeners in 8 out of 26 microbial mat samples of the Svalbard Archipelago in the Arctic. The congeners, of which [Asp3, ADMAdda5, Dhb7] MC-LR was most abundant, were similar to those reported in other polar habitats. Microcystins were also determined using an Adda-specific enzyme-linked immunosorbent assay (Adda-ELISA). Nostoc sp. was identified as a putative toxin producer using molecular methods that targeted 16S rRNA genes and genes involved in microcystin production. The mcy genes detected showed highest similarities to other Arctic or Antarctic sequences. The LC-MS precursor ion screening method could be useful for microcystin detection in unusual matrices such as benthic biofilms or lichen. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessArticle Co-Occurrence of Microcystins and Taste-and-Odor Compounds in Drinking Water Source and Their Removal in a Full-Scale Drinking Water Treatment Plant
Received: 1 December 2017 / Revised: 25 December 2017 / Accepted: 28 December 2017 / Published: 2 January 2018
Cited by 1 | PDF Full-text (1621 KB) | HTML Full-text | XML Full-text
Abstract
The co-occurrence of cyanotoxins and taste-and-odor compounds are a growing concern for drinking water treatment plants (DWTPs) suffering cyanobacteria in water resources. The dissolved and cell-bound forms of three microcystin (MC) congeners (MC-LR, MC-RR and MC-YR) and four taste-and-odor compounds (geosmin, 2-methyl isoborneol,
[...] Read more.
The co-occurrence of cyanotoxins and taste-and-odor compounds are a growing concern for drinking water treatment plants (DWTPs) suffering cyanobacteria in water resources. The dissolved and cell-bound forms of three microcystin (MC) congeners (MC-LR, MC-RR and MC-YR) and four taste-and-odor compounds (geosmin, 2-methyl isoborneol, β-cyclocitral and β-ionone) were investigated monthly from August 2011 to July 2012 in the eastern drinking water source of Lake Chaohu. The total concentrations of microcystins and taste-and-odor compounds reached 8.86 μg/L and 250.7 ng/L, respectively. The seasonal trends of microcystins were not consistent with those of the taste-and-odor compounds, which were accompanied by dominant species Microcystis and Dolichospermum. The fate of the cyanobacteria and metabolites were determined simultaneously after the processes of coagulation/flocculation, sedimentation, filtration and chlorination in the associated full-scale DWTP. The dissolved fractions with elevated concentrations were detected after some steps and the breakthrough of cyanobacteria and metabolites were even observed in finished water. Chlorophyll-a limits at intake were established for the drinking water source based on our investigation of multiple metabolites, seasonal variations and their elimination rates in the DWTP. Not only microcystins but also taste-and-odor compounds should be taken into account to guide the management in source water and in DWTPs. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Graphical abstract

Review

Jump to: Research

Open AccessReview A Systematic Literature Review for Evidence of Aphanizomenon flos-aquae Toxigenicity in Recreational Waters and Toxicity of Dietary Supplements: 2000–2017
Received: 15 May 2018 / Revised: 14 June 2018 / Accepted: 15 June 2018 / Published: 21 June 2018
PDF Full-text (550 KB) | HTML Full-text | XML Full-text
Abstract
Previous studies of recreational waters and blue-green algae supplements (BGAS) demonstrated co-occurrence of Aphanizomenon flos-aquae (AFA) and cyanotoxins, presenting exposure risk. The authors conducted a systematic literature review using a GRADE PRISMA-p 27-item checklist to assess the evidence for toxigenicity of AFA in
[...] Read more.
Previous studies of recreational waters and blue-green algae supplements (BGAS) demonstrated co-occurrence of Aphanizomenon flos-aquae (AFA) and cyanotoxins, presenting exposure risk. The authors conducted a systematic literature review using a GRADE PRISMA-p 27-item checklist to assess the evidence for toxigenicity of AFA in both fresh waters and BGAS. Studies have shown AFA can produce significant levels of cylindrospermopsin and saxitoxin in fresh waters. Toxicity studies evaluating AFA-based BGAS found some products carried the mcyE gene and tested positive for microcystins at levels ≤ 1 μg microcystin (MC)-LR equivalents/g dry weight. Further analysis discovered BGAS samples had cyanotoxins levels exceeding tolerable daily intake values. There is evidence that Aphanizomenon spp. are toxin producers and AFA has toxigenic genes such as mcyE that could lead to the production of MC under the right environmental conditions. Regardless of this ability, AFA commonly co-occur with known MC producers, which may contaminate BGAS. Toxin production by cyanobacteria is a health concern for both recreational water users and BGAS consumers. Recommendations include: limit harvesting of AFA to months when toxicity is lowest, include AFA in cell counts during visible blooms, and properly identify cyanobacteria species using 16S rRNA methods when toxicity levels are higher than advisory levels. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Figures

Figure 1

Open AccessReview In Vitro Toxicological Assessment of Cylindrospermopsin: A Review
Toxins 2017, 9(12), 402; https://doi.org/10.3390/toxins9120402
Received: 6 November 2017 / Revised: 12 December 2017 / Accepted: 13 December 2017 / Published: 16 December 2017
Cited by 3 | PDF Full-text (371 KB) | HTML Full-text | XML Full-text
Abstract
Cylindrospermopsin (CYN) is a cyanobacterial toxin that is gaining importance, owing to its increasing expansion worldwide and the increased frequency of its blooms. CYN mainly targets the liver, but also involves other organs. Various mechanisms have been associated with its toxicity, such as
[...] Read more.
Cylindrospermopsin (CYN) is a cyanobacterial toxin that is gaining importance, owing to its increasing expansion worldwide and the increased frequency of its blooms. CYN mainly targets the liver, but also involves other organs. Various mechanisms have been associated with its toxicity, such as protein synthesis inhibition, oxidative stress, etc. However, its toxic effects are not yet fully elucidated and additional data for hazard characterization purposes are required. In this regard, in vitro methods can play an important role, owing to their advantages in comparison to in vivo trials. The aim of this work was to compile and evaluate the in vitro data dealing with CYN available in the scientific literature, focusing on its toxicokinetics and its main toxicity mechanisms. This analysis would be useful to identify research needs and data gaps in order to complete knowledge about the toxicity profile of CYN. For example, it has been shown that research on various aspects, such as new emerging toxicity effects, the toxicity of analogs, or the potential interaction of CYN with other cyanotoxins, among others, is still very scarce. New in vitro studies are therefore welcome. Full article
(This article belongs to the Special Issue Cyanobacteria and Cyanotoxins: New Advances and Future Challenges)
Back to Top