Abstract from a paper by Ujvarosi et al. (2019), published in Chemospere :
Microginins (MGs) are bioactive metabolites mainly produced by Microcystis spp., (Cyanobacteria) commonly found in eutrophic environments. In this study, the cytotoxic and genotoxic activities of four MG congeners (MG FR3, MG GH787, cyanostatin B, MGL 402) and a well characterized cyanobacterial extract B-14-01 containing these metabolites were evaluated in the human hepatocellular carcinoma (HepG2) cell line. The cytotoxicity was measured with the MTT assay, while genotoxicity was studied with the comet, γH2AX and cytokinesis block (CBMN) micronucleus assays. The viability of cells after 24 h was significantly affected only by the extract, whereas after 72 h a concentration dependent decrease in cell proliferation was observed for the extract and tested microginins, with MGL 402 being the most potent and MG FR3 the least potent congener. The extract and all tested congeners induced DNA strand breaks after 4 and 24 h exposure. The most potent was the extract, which induced concentration and time dependent increase in DNA damage at concentrations ≥0.01 μg mL−1. Among microginins the most potent was MGL 402 (increase in DNA strand breaks at ≥ 0.01 μg mL−1) and MG FR3 was the least potent (increase in DNA strand breaks at ≥ 1 μg mL−1). However, no induction of DNA double strand breaks was observed after 24 and 72-h exposure to the cyanobacterial extract or MGs. Induction of genomic instability was observed in cells exposed to MG GH787, cyanostatin B and the extract B-14-01. This study is the first to provide the evidence that microginins exert genotoxic activity.
The paper is a product of joined research by groups in Slovenia and Hungary and features CYANOCOST members Bojana Zegura, Gabor Vasas, Klara Hercog, Metka Filipic. The authors acknowledge CYANOCOST.
Andrea Zsuzsanna Ujvárosi, Klara Hercog, Milán Riba, Sándor Gonda, Metka Filipič, Gábor Vasas, Bojana Žegura (2019). “The cyanobacterial oligopeptides microginins induce DNA damage in the human hepatocellular carcinoma (HepG2) cell line”, Chemosphere, Volume 240, https://doi.org/10.1016/j.chemosphere.2019.124880.
Harmful algal blooms formed by cyanobacteria (cyanoHABs) not only deteriorate ecosystem services but cause significant economic losses because of managing and treating drinking water and food supplies. Among those toxins, most prominent are the microcystins (and related peptides), i.e. by inhibiting eukaryotic protein phosphatases 1 and 2A of higher organisms. Intracellular toxic peptides can be released into the surrounding environment either through cell lysis or through active transport out of the cell.
One possibility to investigate cyanotoxins on the individual cell level is the so-called bioorthogonal labeling. In vivo labeling of cyanotoxins/peptides is based on the discovery of unspecific key enzymes involved in the synthesis pathway of those compounds which also can use non-natural functional groups as precursors. The resulting modified molecule is subsequently labeled by a fluorophore through a so-called click chemistry reaction. We will perform cyanotoxin/peptide labeling and high resolution imaging to localize, quantify and reveal inter/intracellular peptide storage and release using various isolates varying substantially in intra- and extracellular toxic peptide content (0-60% of the total content).
The tasks of this position will include (i) the integration of the data on cyanotoxin/peptide localization, and labeling of metabolites, (ii) experiments on strain-specific variation and stress-induced variation. The PhD candidate will be responsible for collecting the data on peptide localization using high resolution microscopy and further analysis using advanced imaging software, as well as to analyze the strain-specific and stress induced variation under controlled laboratory conditions.
Download the full call (pdf).
Further Information: Assoc. Prof. Dr. Rainer Kurmayer
Research Department for Limnology Mondsee, University of Innsbruck, Austria
For application please send a motivation letter together with a CV (in English) until 15 September 2019.
A new paper by Konstantinou et al. from Cyanolab AUTH (Head: Dr. Spyros Gkelis), published in Journal of Phycology. The authors propose a novel marine genus Leptothoe gen. nov. and describe three new sponge-associated species: Le. sithoniana, Le. kymatousa, and Le. spongobia, based on a combination of molecular, chemical and morphological approach. The new sponge-associated Leptothoe species show distinct characters compared to other marine Leptolyngbyaceae, reinforcing the investigation of cyanobacterial diversity associated with sponges. Interestingly, Leptothoe spongobia TAU-MAC 1115 isolated from the sponge Acanthella acuta was shown to produce microcystin-RR indicating that microcystin production among marine cyanobacteria could be more widespread than previously determined.
Konstantinou, D., Voultsiadou, E., Panteris, E., Zervou, S. K., Hiskia, A., & Gkelis, S. (2019). Leptothoe, a new genus of marine cyanobacteria (Synechococcales) and three new species associated with sponges from the Aegean Sea. Journal of phycology. https://doi.org/10.1111/jpy.12866
We are pleased to announce ProSynFest2o20 (March 18-21, 2020 in Cordoba, Spain), a conference almost entirely devoted to the marine picocyanobacteria Prochlorococcus and Synechococcus. It starts with an (optional) one-day technical workshop on March 18th. The conference itself lasts 3 days and will gather most world specialists of marine picocyanobacteria.
The conference program is available here: www.prosynfest2020.com/
Dr. F. Partensky, member of the organizing committee
CYanoBox (ENTERPRISES / 0618/0157) is a 2-year project that aims to develop an autonomous, affordable (cost-effective), easy-to-use, and reliable tool for monitoring cyanobacterial contaminated surface waterbodies. Such a tool will be extremely helpful to local and competent authorities to minimize exposure to the toxic compounds released by the blooms. The Cyprus Research Innovation Centre (Cy-RIC) and the Water Treatment Laboratory-AQUA of the Cyprus University of Technology have partnered for the completion of this project.
I would like to ask you to spend 5 minutes and complete the survey (link and password provided below). This will help us immensely with the system requirements.
Please feel free to share to anyone third party (including water companies and competent authorities). https://ec.europa.eu/eusurvey/runner/CYANOBOX2019
Thank you so much!
Maria G. Antoniou (Ph.D.), Assistant Professor, Cyprus University of Technology, Water Treatment Laboratory-Aqua
The combination of liquid chromatography with mass spectrometry (LC-MS) is a valuable tool for the determination of algal toxins contained at trace levels in complex matrices thanks to its high sensitivity, selectivity and ability to deal with the structural diversity and labile nature of the toxins. Targeted LC tandem MS (LC-MS/MS) approaches are already efficiently employed worldwide to monitor toxin distribution in the environment and in the food chain. At the same time, untargeted approaches based on high resolution MS (LC-HRMS) have generally disclosed the presence of a much higher number and types of toxins and made straightforward elucidation of the gross structure of the unknowns based on the interpretation of their fragmentation patterns.
In view of the plethora of LC-MS/MS and LC-HRMS methods that have been developed so far, the need exists for critical reviews that, besides summarizing the methodologies for determination of each toxin-group, single out the main challenges to be addressed in the next future for marine, freshwater and fish-killing toxins. Collaborative efforts among scientists are strongly encouraged both in the field of the regulated toxins in EU and the emerging ones to build the rational basis for inter-laboratory validation trials, where needed. Original research articles reporting LC-MS based identification of emerging issues for water and food safety potentially associated with climate change as well as recent advancements in LC-MS data acquisition and treatment (On-line SPE-LC-MS, 2D-LC-MS, Metabolomics, among others) will be also included in this Special Issue.
More information can be found at: https://www.mdpi.com/journal/toxins/special_issues/lcms_Algal
Deadline for manuscript submissions is 31 December 2019
Guest Editors: Carmela Dell’Aversano and Luciana Tartaglione, Department of Pharmacy, University of Napoli Federico II
Cyanobacteria are an ancient lineage of oxygenic photosynthetic bacteria found in a broad range of habitats, from soil to oceans, where they play important roles in the global nitrogen and carbon cycles. They are known for the toxic blooms they form in fresh water bodies around the world and the production of toxins, posing a threat to human and environmental health. Despite the tremendous effort to understand the biosynthesis, toxicity, and occurrence of cyanobacteria secondary metabolites, the biological role of these compounds still remains relatively unknown. Various hypotheses in this regard have been put forward, encompassing both intracellular effects such as nutrient storage, light adaptation, and protection against oxidative stress, and extracellular functions including quorum sensing, allelopathic interactions, nutrient acquisition, colony formation, and grazing defense. The existing evidence on the potential role of cyanotoxins is mostly based on experimental studies and require further confirmation by in-field observations.
This Special Issue is destined to gather reviews, original experimental papers, and short notes reporting findings on experimental and in-field observations that aim to advance our understanding of the biological role of cyanotoxins.
Dr. Spyros Gkelis
Dr. Piotr Rzymski
Deadline for manuscript submissions: 31 December 2019
Special issue webpage.
The 19th International Conference on Harmful Algae will take place from the 11th to the 16th of October 2020 in La Paz, BCS, Mexico, being the 2nd ICHA conference held in Latin America. As the last conferences, the 2020 conference will include topics related with the understanding of the causes, evolution and impacts of harmful microalgae and cyanobacteria. We are planning an enjoyable meeting where scientists can present their research, share their ideas, establish new collaborations, and connect the science on harmful algae with the beneficiaries of this research.
La Paz is an ideal city for the meeting where many academic institutes are found. It is a small, secure and quiet city, with beautiful surroundings, which is visited by many international tourists and academics year round. The average temperature in October is between 21 and 34 °C.
For some countries a visa may be required. Please check visa regulations well in advance with your local Mexican Consulate for official instructions on the specific visa regulations and application procedures.
As the major host of the conference, ISSHA will support the event with various activities: Travel awards to students and post-docs, several achievement awards, and ISSHA auction.
Looking forward to seeing you in La Paz, Mexico!
The Organizing Committee,
Dr Petra Visser is giving a lecture on “Mitigation of cyanobacteria in lakes by dilute hydrogen peroxide” in the Library Hall of NCSR Demokritos, on 21st March 2019 at 13:00.
Dr Petra Visser is Associate Professor in the Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam. Her research interests include physiology and ecology of cyanobacteria and algae, toxic cyanobacteria, eutrophication, water management, macroalgae, benthic cyanobacterial mats, coral reefs. She has carried out pioneering work on the use of hydrogen peroxide for selective suppression of harmful cyanobacteria in entire lakes. Among others, she has been Leader of the Working Group “Prevention and Control of Toxic Cyanobacteria and Cyanotoxins” of the CYANOCOST network and Editor of a recent Special Issue on “Cyanobacterial blooms – Ecology, prevention, mitigation and control” in Aquatic Ecology.
Description of the event
From the webpage of the Frontiers Research Topic:
A sustainable food system is insecure if toxins are a threat. There are three types of natural non-proteinaceous toxins that compromise reliability of food systems: cyanotoxins for freshwater aquatic products, phycotoxins for seafood, and mycotoxins mainly for cereals (also for other plant-based foods and food-products of animal origin).
This Research Topic aims to focus on several knowledge gaps that require in-depth research, with an emphasis on new or emerging toxins recently appearing due to global warming and international trade. In this context, several important issues related to toxins stand out for which new information and scientific evidence should be provided. These issues include: monitoring and analytical challenges (including the requirement for certified reference materials), the need for better understanding of toxin mode of action and toxicology, as well as the need to improve risk assessment, and the development of novel mitigation strategies.
We invite scientists from these relevant fields to contribute to this exciting area of research that combines pharmacology, analytical chemistry, toxicology, mycology, phycology, and food safety.
Topic Editors : Luis M. Botana, Panagiota Katikou, Maria J. Sainz, Alison Robertson
View details about this Research Topic here.