Can Microcystis spp. blooms be used in animal feeds?

A recent paper by Chen et al. published in Science of the Total Environment reviews the challenges of using blooms of Microcystis spp. in animal feeds.

Highlights (from the paper):

  • Microcystis causes toxicity to mollusks, crustaceans, fish, amphibians, mammals and birds.
  • Microcystis induces toxicity in liver, kidney, intestine, spleen and other organs.
  • Fish fed Microcystis may be not safe for consumption for humans.
  • Microbial pathogens may be present in cyanobacterial blooms.

Reference:

Liang Chen, John P. Giesy, Ondrej Adamovsky, Zorica Svirčev, Jussi Meriluoto, Geoffrey A. Codd, Biljana Mijovic, Ting Shi, Xun Tuo, Shang-Chun Li, Bao-Zhu Pan, Jun Chen, Ping Xie.
Challenges of using blooms of Microcystis spp. in animal feeds: A comprehensive review of nutritional, toxicological and microbial health evaluation. Science of The Total Environment, Volume 764, 2021, https://doi.org/10.1016/j.scitotenv.2020.142319

Cyanotoxins in Bloom – Special Issue, Toxins

Dear colleagues,

The open access journal Toxins (ISSN 2072-6651, IF 3.895) is pleased to announce that we have launched a new Special Issue entitled:

“Cyanotoxins in Bloom: Ever-Increasing Occurrence and Global Distribution of Freshwater Cyanotoxins from Planktic and Benthic Cyanobacteria”.

We are serving as Guest Editors for this issue.

We would like to cordially invite you to contribute an article to the Special Issue. For more information on the issue, please visit the Special Issue website at

https://www.mdpi.com/journal/toxins/special_issues/Cyanotoxins_Bloom .

Kind regards,

Guest Editors

Dr. Triantafyllos Kaloudis

Athens Water Supply and Sewerage Company – EYDAP SA, Organic Micropollutants Lab – Quality Control Department, Flias 11, 13674 Menidi, Greece

Dr. Anastasia Hiskia

National Center for Scientific Research “DEMOKRITOS”, Institute of Nanoscience and Nanotechnology, Partiarchi Grigoriou E & Neapoleos 27 str., 15341, Agia Paraskevi, Athens, Greece

Dr. Theodoros Triantis

National Center for Scientific Research “DEMOKRITOS”, Institute of Nanoscience and Nanotechnology, Partiarchi Grigoriou E & Neapoleos 27 str., 15341, Agia Paraskevi, Athens, Greece

New microginins from cyanobacteria of Greek lakes

The first report of microginins isolated from cyanobacteria of Greek lakes was published by Zervou et al. in Chemosphere. As many as 36 new structures of microginins were elucidated with MS/MS techniques. The work was supported by a CYANOCOST STSM grant of Sevasti Zervou (NCSR Demokritos) to Hanna Mazur-Marzec (University of Gdansk).

The paper acknowledges CYANOCOST.

Reference:

Sevasti – Kiriaki Zervou, Spyros Gkelis, Triantafyllos Kaloudis, Anastasia Hiskia, Hanna Mazur-Marzec (2020). New microginins from cyanobacteria of Greek freshwaters,
Chemosphere, Volume 248, 125961. https://doi.org/10.1016/j.chemosphere.2020.125961.

 

Peptide patterns of Nostoc-like strains from alkali grassland areas

A paper by Riba et al. in Algal Research reports the chemotyping of terrestrial Nostoc-like isolates from alkali grassland areas by non-targeted peptide analysis.

From the Abstract:

The Nostoc genus is a well-known heterocytous, filamentous cyanobacterium which can be found all over the world. The size of terrestrial and/or freshwater colonies can be microscopic and macroscopic as well. In addition, Nostoc species are one of the most common photosynthetic cyanobacterial partners in symbiotic interactions. Terrestrial cyanobacterial colonies were collected and isolated in this study from various alkali grassland habitats (Great Hungarian Plain). Altogether 133 colonies were isolated from the 65 collected samples. The peptide patterns of the Nostoc-like strains were examined using HPLC-ESI-MS/MS and 41 peptides were identified from 45 isolated Nostoc-like strains; these compounds belonged to 4 different peptide classes. Twelve nostoginin/microginin, 16 anabaenopeptin, 12 banyaside/suomilide variants were identified. 37% of our isolated Nostoc-like strains produced some of the peptide metabolites we tested. These strains showed distinct chemotypes according to their peptide patterns, and can be divided into 4 groups based on their metabolisms. Strains either contained: (1) nostoginins/microginins, (2) anabaenopeptins, (3) anabaenopeptins and banyasides or (4) banyasides as major compounds. Banyasides were present in many of our strains and showed very high intensity in some cases. A number of previously unknown banyaside variants have been identified.

The paper acknowledges CYANOCOST.

Reference:

Milán Riba, Attila Kiss-Szikszai, Sándor Gonda, Péter Parizsa, Balázs Deák, Péter Török, Orsolya Valkó, Tamás Felföldi, Gábor Vasas (2020). Chemotyping of terrestrial Nostoc-like isolates from alkali grassland areas by non-targeted peptide analysis. Algal Research 46, 101798. https://doi.org/10.1016/j.algal.2020.101798.

Effects of hydrogen peroxide on cyanobacteria and microcystins in irrigation water.

A new paper by Spoof et al. in Environmental Science and Pollution Research reports a series of experiments where lysis of cyanobacteria in abstracted lake water was induced by the use of hydrogen peroxide.

From the abstract:

This paper reports a series of experiments where lysis of cyanobacteria in abstracted lake water was induced by the use of hydrogen peroxide and the fate of released MCs was followed. The hydrogen peroxide–treated water was then used for spray irrigation of cultivated spinach and possible toxin accumulation in the plants was monitored. The water abstracted from Lake Köyliönjärvi, SW Finland, contained fairly low concentrations of intracellular MC prior to the hydrogen peroxide treatment (0.04 μgL −1 in July to 2.4 μgL −1 in September 2014). Hydrogen peroxide at sufficient doses was able to lyse cyanobacteria efficiently but released MCs were still present even after the application of the highest hydrogen peroxide dose of 20 mg L−1. No traces of MC were detected in the spinach leaves. The viability of moving phytoplankton and zooplankton was also monitored after the application of hydrogen peroxide. Hydrogen peroxide at 10 mg L−1 or higher had a detrimental effect on the moving phytoplankton and zooplankton.

The paper acknowledges CYANOCOST.

Reference:

Spoof, L., Jaakkola, S., Važić, T. Važić, T., Häggqvist, K., Kirkkala, T., Ventelä, A-M., Kirkkala, T., Svirčev, Z., Meriluoto, J. Elimination of cyanobacteria and microcystins in irrigation water—effects of hydrogen peroxide treatment. Environ Sci Pollut Res (2020). https://doi.org/10.1007/s11356-019-07476-x

New research sheds light on the underlying mechanisms of 2,4 DABA neurotoxic effects

A new paper by S. Spacic et al. in Aquatic Toxicology, presents important findings with regards to the mechanisms underlying 2,4-DABA neurotoxicity. From the abstract:

“Recent studies suggest that 2,4-DABA, a neurotoxic excitatory amino acid present in virtually all environments, but predominantly in aquatic ecosystems may be a risk factor for development of neurodegenerative diseases in animals and humans. Despite its neurotoxicity and potential environmental importance, mechanisms underlying the excitatory and putative excitotoxic action of 2,4-DABA in neurons are still unexplored. We previously reported on extensive two-stage membrane depolarization and functional disturbances in leech Retzius neurons induced by 2,4-DABA. Current study presents the first detailed look into the electrophysiological processes leading to this depolarization. Intracellular recordings were performed on Retzius neurons of the leech Haemopis sanguisuga using glass microelectrodes and input membrane resistance (IMR) was measured by injecting hyperpolarizing current pulses through these electrodes. Results show that the excitatory effect 2,4-DABA elicits on neurons’ membrane potential is dependent on sodium ions. Depolarizing effect of 5·10−3 mol/L 2,4-DABA in sodium-free solution was significantly diminished by 91% reducing it to 3.26 ± 0.62 mV and its two-stage nature was abrogated. In addition to being sodium-dependent, the depolarization of membrane potential induced by this amino acid is coupled with an increase of membrane permeability, as 2,4-DABA decreases IMR by 8.27 ± 1.47 MΩ (67.60%). Since present results highlight the role of sodium ions, we investigated the role of two putative sodium-dependent mechanisms in 2,4-DABA-induced excitatory effect – activation of ionotropic glutamate receptors and the electrogenic transporter for neutral amino acids. Excitatory effect of 5·10−3 mol/L 2,4-DABA was partially blocked by 10-5 mol/L 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) a non-NMDA receptor antagonist as the first stage of membrane depolarization was significantly reduced by 2.59 ± 0.98 mV (40%), whilst second stage remained unaltered. Moreover, involvement of the sodium-dependent transport system for neutral amino acids was investigated by equimolar co-application of 5·10−3 mol/L 2,4-DABA and L-alanine, a competitive inhibitor of this transporter. Although L-alanine exhibited no effect on the first stage of membrane depolarization elicited by 2,4-DABA, it substantially reduced the second stage (the overall membrane depolarization) from 39.63 ± 2.22 mV to 16.28 ± 2.58 mV, by 58.92%. We therefore propose that the electrophysiological effect of 2,4-DABA on Retzius neurons is mediated by two distinct mechanisms, i.e. by activation of ionotropic glutamate receptor that initiates the first stage of membrane depolarization followed by the stimulation of an electrogenic sodium-dependent neutral amino acid transporter, leading to additional influx of positive charge into the cell and the second stage of depolarization.”

The paper acknowledges CYANOCOST.

Reference:

Svetolik Spasic, Marija Stanojevic, Jelena Nesovic Ostojic, Sanjin Kovacevic, Jasna Todorovic, Marko Dincic, Vladimir Nedeljkov, Milica Prostran, Srdjan Lopicic (2020).
Two distinct electrophysiological mechanisms underlie extensive depolarization elicited by 2,4 diaminobutyric acid in leech Retzius neurons. Aquatic Toxicology 220, 105398.
https://doi.org/10.1016/j.aquatox.2019.105398.

 

Frontiers topic: Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches

This Frontiers Research Topic presents research papers and reviews that explore novel approaches expanding our understanding of the development of toxic phytoplankton blooms and their immense performance in a changing environment, with particular focus on Microcystis sp. It aims to address various aspects of cyanobacterial blooms including the following:

• abiotic and biotic drivers of cyanobacteria blooms

• biological role of secondary metabolites, including cyanotoxins, in the bloom’s lifecycle,

• allelopathic and info-chemical interactions between microorganisms involved in toxic blooms,

• competition in host/parasite interactions, including cy-anophages,

• novel strategies for mitigation of cyanobacterial blooms.

Topic Editors:

Aaron Kaplan, Hebrew University of Jerusalem, Israel),
Rainer Kurmayer, University of Innsbruck, Austria,
Assaf Sukenik, Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, Leon H. Charney School of Marine Sciences, University of Haifa, Migdal, Israel.

Deadline for submission of abstracts: 01 April 2020.

Link to the webpage of this Frontiers Topic

 

NaToxAq Conference call for abstracts (Brno, 10-12 June 2020)

Natural toxins can pose varying degrees of risk towards ecosystems and even human health. Natural Toxins: Environmental Fate and Safe Water Supply is the first international conference focusing solely on the topic of natural compounds affecting the quality of our water resources and drinking water. The conference provides a unique platform to present latest findings in plenum and develop new ideas among experts and young researchers, setting the direction for future research in this rapidly evolving field and help guide water legislation.

A call for abstracts in now open, with deadline on January 30, 2020.

Visit the NaToxAq Conference webpage.

Download the conference flyer.