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Freshwater Cyanobacterial Toxins: Developments in Monitoring, Identification, Impacts and Factors Influencing Production

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

Deadline for manuscript submissions: closed (30 September 2019) | Viewed by 21733

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Special Issue Editors

Dr. Simon Mitrovic

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Guest Editor

Freshwater and Estuarine Research Group, School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
Interests: cyanobacterial blooms; river management; fish kills; river and lake ecology
Special Issues, Collections and Topics in MDPI journals

Dr. Ambrose Furey

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Guest Editor

Cork Institute of Technology (CIT), Ireland

Special Issue Information

Dear Colleagues,

Freshwater cyanobacteria are known to produce a suite of different chemicals that can be toxic to many organisms. These toxins can have adverse impacts on humans, animals, and even aquatic and terrestrial plants. Further information about cyanobacterial toxins is required to better understand and manage their risks in freshwater environments. This Special Issue aims to bring together papers that provide new information on the monitoring of cyanobacterial toxins and the identification of toxins in freshwater environments. Further, papers are invited that develop our knowledge of how cyanobacterial toxins impact humans, as well as different aquatic and terrestrial organisms. Papers that better develop our understanding of how toxin production by cyanobacteria is regulated are also welcomed.

Assoc. Prof. Simon Mitrovic
Dr. Ambrose Furey
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 submissions that pass pre-check are 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 2700 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

freshwater
toxins
cyanobacteria
neurotoxins
hepatotoxins
analytical techniques
multi-class toxin determination
risk management
regulation

Published Papers (5 papers)

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Research

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21 pages, 2366 KiB

Open AccessEditor’s ChoiceArticle

First Detection of Microcystin-LR in the Amazon River at the Drinking Water Treatment Plant of the Municipality of Macapá, Brazil

by Elane D.C. Oliveira, Raquel Castelo-Branco, Luis Silva, Natalina Silva, Joana Azevedo, Vitor Vasconcelos, Silvia Faustino and Alan Cunha

Toxins 2019, 11(11), 669; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11110669 - 15 Nov 2019

Cited by 17 | Viewed by 4037

Abstract

Human poisoning by microcystin has been recorded in many countries, including Brazil, where fatal cases have already occurred. The Amazon River is the main source of drinking water in municipalities such as Macapá, where there is no monitoring of cyanobacteria and cyanotoxins. This study investigated the presence of cyanobacteria and cyanotoxins in samples from a drinking water treatment plant (DWTP) that catches water from the Amazon River. The toxin analyses employed ELISA, LC/MS, and molecular screening for genes involved in the production of cyanotoxins. The sampling was carried out monthly from April 2015 to April 2016 at the intake (raw water) and exit (treated water) of the DWTP. This study reports the first detection of microcystin-LR (MC-LR) in the Amazon River, the world’s largest river, and in its treated water destined for drinking water purposes in Macapá, Brazil. The cyanobacterial density and MC-LR concentration were both low during the year. However, Limnothrix planctonica showed a density peak (± 900 cells mL⁻¹) in the quarter of June–August 2015, when MC-LR was registered (2.1 µg L⁻¹). Statistical analyses indicate that L. planctonica may produce the microcystin. Full article

(This article belongs to the Special Issue Freshwater Cyanobacterial Toxins: Developments in Monitoring, Identification, Impacts and Factors Influencing Production)

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13 pages, 1420 KiB

Open AccessArticle

Uptake, Growth, and Pigment Changes in Lemna minor L. Exposed to Environmental Concentrations of Cylindrospermopsin

by Nelida Cecilia Flores-Rojas, Maranda Esterhuizen-Londt and Stephan Pflugmacher

Toxins 2019, 11(11), 650; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11110650 - 07 Nov 2019

Cited by 8 | Viewed by 2856

Abstract

Cylindrospermopsin (CYN)-producing cyanobacterial blooms such as Raphidiopsis, Aphanizomenon, Anabaena, Umezakia, and Lyngbya spp. are occurring more commonly and frequently worldwide. CYN is an environmentally stable extracellular toxin, which inhibits protein synthesis, and, therefore, can potentially affect a wide variety of aquatic biota. Submerged and floating macrophytes, as primary producers in oligotrophic habitats, are at risk of exposure and information on the effects of CYN exposure at environmentally relevant concentrations is limited. In the present study, we investigated CYN uptake in the floating macrophyte Lemna minor with exposure to reported environmental concentrations. The effects were evaluated in terms of bioaccumulation, relative plant growth, and number of fronds per day. Variations in the concentrations and ratios of the chlorophylls as stress markers and carotenoids as markers of oxidative stress defense were measured. With exposure to 25 μg/L, L. minor could remove 43% of CYN within 24 h but CYN was not bioaccumulated. Generally, the pigment concentrations were elevated with exposure to 0.025, 0.25, and 2.5 μg/L CYN after 24 h, but normalized quickly thereafter. Changes in relative plant growth were observed with exposure to 0.25 and 2.5 μg/L CYN. Adverse effects were seen with these environmentally realistic concentrations within 24 h; however, L. minor successfully recovered within the next 48–96 h. Full article

(This article belongs to the Special Issue Freshwater Cyanobacterial Toxins: Developments in Monitoring, Identification, Impacts and Factors Influencing Production)

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13 pages, 894 KiB

Open AccessEditor’s ChoiceArticle

Production of β-methylamino-L-alanine (BMAA) and Its Isomers by Freshwater Diatoms

by Jake P. Violi, Jordan A. Facey, Simon M. Mitrovic, Anne Colville and Kenneth J. Rodgers

Toxins 2019, 11(9), 512; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11090512 - 02 Sep 2019

Cited by 30 | Viewed by 5519

Abstract

β-methylamino-L-alanine (BMAA) is a non-protein amino acid that has been implicated as a risk factor for motor neurone disease (MND). BMAA is produced by a wide range of cyanobacteria globally and by a small number of marine diatoms. BMAA is commonly found with two of its constitutional isomers: 2,4-diaminobutyric acid (2,4-DAB), and N-(2-aminoethyl)glycine (AEG). The isomer 2,4-DAB, like BMAA, has neurotoxic properties. While many studies have shown BMAA production by cyanobacteria, few studies have looked at other algal groups. Several studies have shown BMAA production by marine diatoms; however, there are no studies examining freshwater diatoms. This study aimed to determine if some freshwater diatoms produced BMAA, and which diatom taxa are capable of BMAA, 2,4-DAB and AEG production. Five axenic diatom cultures were established from river and lake sites across eastern Australia. Cultures were harvested during the stationary growth phase and intracellular amino acids were extracted. Using liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS), diatom extracts were analysed for the presence of both free and protein-associated BMAA, 2,4-DAB and AEG. Of the five diatom cultures analysed, four were found to have detectable BMAA and AEG, while 2,4-DAB was found in all cultures. These results show that BMAA production by diatoms is not confined to marine genera and that the prevalence of these non-protein amino acids in Australian freshwater environments cannot be solely attributed to cyanobacteria. Full article

(This article belongs to the Special Issue Freshwater Cyanobacterial Toxins: Developments in Monitoring, Identification, Impacts and Factors Influencing Production)

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16 pages, 2688 KiB

Open AccessArticle

Lipopolysaccharides from Microcystis Cyanobacteria-Dominated Water Bloom and from Laboratory Cultures Trigger Human Immune Innate Response

by Zdena Moosová, Lenka Šindlerová, Barbora Ambrůzová, Gabriela Ambrožová, Ondřej Vašíček, Mirna Velki, Pavel Babica and Lukáš Kubala

Toxins 2019, 11(4), 218; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11040218 - 11 Apr 2019

Cited by 17 | Viewed by 3502

Abstract

Massive toxic blooms of cyanobacteria represent a major threat to water supplies worldwide. Here, the biological activities of lipopolysaccharide (LPS) isolated from Microcystis aeruginosa, the most prominent cyanobacteria in water bloom, were studied. LPS was isolated from complex environmental water bloom samples dominated by M. aeruginosa, and from laboratory cultures of non-axenic as well as axenic M. aeruginosa strains PCC7806 and HAMBI/UHCC130. Employing human blood-based in vitro tests, the LPS isolated from complex water bloom revealed the priming of both major blood phagocyte population monocytes and polymorphonuclear leukocytes documented by the increased surface expression of CD11b and CD66b. This was accompanied by a water bloom LPS-mediated dose-dependent induction of tumor necrosis factor α, interleukin-1β, and interleukin-6 production. In accordance with its priming effects, water bloom LPS induced significant activation of p38 and ERK1/2 kinases, as well as NF-κB phosphorylation, in isolated polymorphonuclear leukocytes. Interestingly, the pro-inflammatory potential of LPS from the axenic strain of M. aeruginosa was not lower compared to that of LPS isolated from non-axenic strains. In contrast to the biological activity, water bloom LPS revealed almost twice higher pyrogenicity levels compared to Escherichia coli LPS, as analyzed by the PyroGene test. Moreover, LPS from the non-axenic culture exhibited higher endotoxin activity in comparison to LPS from axenic strains. Taking the above findings together, M. aeruginosa LPS can contribute to the health risks associated with contamination by complex water bloom mass. Full article

(This article belongs to the Special Issue Freshwater Cyanobacterial Toxins: Developments in Monitoring, Identification, Impacts and Factors Influencing Production)

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Review

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18 pages, 593 KiB

Open AccessEditor’s ChoiceReview

A Review of the Effect of Trace Metals on Freshwater Cyanobacterial Growth and Toxin Production

by Jordan A. Facey, Simon C. Apte and Simon M. Mitrovic

Toxins 2019, 11(11), 643; https://0-doi-org.brum.beds.ac.uk/10.3390/toxins11110643 - 05 Nov 2019

Cited by 63 | Viewed by 5335

Abstract

Cyanobacterial blooms are becoming more common in freshwater systems, causing ecological degradation and human health risks through exposure to cyanotoxins. The role of phosphorus and nitrogen in cyanobacterial bloom formation is well documented and these are regularly the focus of management plans. There is also strong evidence that trace metals are required for a wide range of cellular processes, however their importance as a limiting factor of cyanobacterial growth in ecological systems is unclear. Furthermore, some studies have suggested a direct link between cyanotoxin production and some trace metals. This review synthesises current knowledge on the following: (1) the biochemical role of trace metals (particularly iron, cobalt, copper, manganese, molybdenum and zinc), (2) the growth limitation of cyanobacteria by trace metals, (3) the trace metal regulation of the phytoplankton community structure and (4) the role of trace metals in cyanotoxin production. Iron dominated the literature and regularly influenced bloom formation, with 15 of 18 studies indicating limitation or colimitation of cyanobacterial growth. A range of other trace metals were found to have a demonstrated capacity to limit cyanobacterial growth, and these metals require further study. The effect of trace metals on cyanotoxin production is equivocal and highly variable. Better understanding the role of trace metals in cyanobacterial growth and bloom formation is an essential component of freshwater management and a direction for future research. Full article

(This article belongs to the Special Issue Freshwater Cyanobacterial Toxins: Developments in Monitoring, Identification, Impacts and Factors Influencing Production)

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