Impact of extreme coastal events on a brackish lake on the Burin Peninsula, Newfoundland, Canada.

The impacts of extreme coastal events (ECEs), such as marine inundations or extreme wind events, on lake ecosystems vary widely from minimal to catastrophic. Accurately predicting the response of a specific system remains challenging due to a limited understanding of the attributes that drive the resilience of lakes. In an attempt to better understand the possible impacts of ECEs on shallow brackish lakes, we employed a paleolimnological approach to reconstruct the responses of Broad Pond to four ECEs identifiable from clear sedimentary markers and dated to ca. 1740, 1790, 1862, and 1993 CE. We aimed to evaluate the overall impacts of ECEs on Broad Pond and their specific effects on various hydrobiont groups. We reinvestigated a previously studied sediment core covering the last ca. 400 years by examining terrestrial and aquatic pollen, spores and non-pollen palynomorphs, cladocerans, and chironomids. Additionally, available diatom data were reexamined. Overall, Broad Pond exhibited resilient responses to ECEs, as indicated by mostly limited compositional turnovers in our proxy records. Statistically significant relationships between species composition and ECEs were observed only for diatoms. The only prolonged change identified is the spread of previously near-absent chironomids in the aftermath of a slight lake refreshment likely associated with the ca. 1740 CE event. This event was also followed by a short-lived (ca. 15 years) five-fold increase in the abundance of Scenedesmus that could have been triggered by the effects of the ECE on nutrient availability. The impact of the remaining three ECEs was discernible only in the diatom record, consistently showing a decline in two calcifobic and oligotrophic species, Achnanthidium petersenii and Platessa oblongella, also evident for the ca. 1740 CE event. The relatively minor ecosystem alteration induced by ECEs in Broad Pond lacks a single explanation and requires consideration of multiple site- and event-specific factors.

Controls on coastal flooding in the southern Baltic Sea revealed from the late Holocene sedimentary records.

Climate change and related sea-level rise pose significant threats to lowland coasts. However, the role of key controlling factors responsible for the frequency and landward extent of extreme storm surges is not yet fully understood. Here, we present a high-resolution sedimentary record of extreme storm surge flooding from the non-tidal southern Baltic Sea, spanning two periods: 3.6-2.9 ka BP and 0.7 ka BP until present. Sediments from coastal wetland, including sandy event layers, were analyzed by sedimentological (grain size, loss-on-ignition, micromorphology), geochronological (14C), geochemical (XRF), mineralogical (heavy minerals) and micropaleontological (diatoms) methods. The results show that both periods were characterized by high-frequency of storm surge flooding, in order of 1.3-4.2 events per century. These periods correlate with phases of enhanced storminess in northwest Europe and took place during both rising and fluctuating sea levels. The study shows that the frequency and landward extent of coastal inundation, largely depended on the development of natural barriers (e.g. beach ridges and aeolian foredunes). Thus, in the context of the future coastal storm-surge hazard, the protection of existing coastal barriers and their morphology is essential.

Cyanobacteria in hot pursuit: Characterization of cyanobacteria strains, including novel taxa, isolated from geothermal habitats from different ecoregions of the world.

Well-studied thermal spring microbial mat systems continue to serve as excellent models from which to make discoveries of general importance to microbial community ecology in order to address comprehensively the question of "who is there" in a microbial community. Cyanobacteria are highly adaptable and an integral part of many ecosystems including thermal springs. In this context, we sampled disparate thermal springs, spanning from Iceland and Poland to Greece and Tajikistan. Thirteen (13) strains were isolated and characterised with taxonomic indices and molecular markers (16S-23S rRNA region and cpcBA gene), whilst their thermotolerance was evaluated. Screening for the presence of genes encoding three heat shock proteins, as well as non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) was performed. This approach resulted in the description of two new genera (Hillbrichtia and Amphirytos) and their type species (Hillbrichtia pamiria and Amphirytos necridicus) representing Oscillatoriales and Synechococcales orders, respectively. We also found unique lineages inside the genus Thermoleptolyngbya, describing a novel species (T. hindakiae). We described the presence of sub-cosmopolitan taxa (such as Calothrix, Desertifilum, and Trichormus). Strains were diverse concerning their thermophilic ability with the strains well adapted to high temperatures possessing all three investigated genes encoding heat shock proteins as well as studied PKS and NRPS genes. In this work, we show novel cyanobacteria diversity from thermal springs from disparate environments, possible correlation of thermotolerance and their genetic background, which may have implications on strategic focusing of screening programs on underexploited taxa in these habitats.

Cyanobacterial cell-wall components as emerging environmental toxicants - detection and holistic monitoring by cellular signaling biosensors.

Cyanobacterial blooms constitute a recognized danger to aquatic environment and public health not only due to presence of main group of cyanotoxins, such as microcystins, cylindrospermopsin or anatoxin-a, but also other emerging bioactivities. An innovative approach identifying such bioactivities is the application of cellular biosensors based on reporter genes which detect the impact of cyanobacterial cells and components on actual human cells in a physiological-like setting. In the present study biosensor cell lines detecting four different types of bioactivities (ARE - oxidative stress, NFKBRE - immunomodulatory pathogen-associated molecular patterns, AHRE - persistent organic pollutants, GRE - endocrine disruptors) were exposed to concentrated cyanobacterial cells from 21 environmental bloom samples and from eight cultures (Microcystis aeruginosa, Aphanizomenon flos-aquae, Planktothrix agardhii and Raphidiopsis raciborskii). The AHRE and GRE biosensors did not detect any relevant bioactivity. In turn, ARE biosensors were significantly activated by bloom samples from Jeziorsko (180-250%) and Sulejów (250-400%) reservoirs with the highest cyanobacterial biomass, while activation by cultures was weak/undetectable. The same biosensors were stimulated by microcystin-LR (250%) and anatoxin-a (150%). The NFKBRE biosensors were activated to varying extent (140-650%) by most bloom and culture samples, pointing to potential immunomodulatory toxic effects on humans. Lipopolysaccharide and lipoproteins were identified as responsible for NFKBRE activation (probably via pattern recognition receptors), while peptidoglycan had no bioactivity in this assay. Thus, the holistic approach to sample analysis with the application of cellular biosensors geared towards 4 separate pathways/bioactivities was validated for identification of novel bioactivities in organisms with recognized public health significance (e.g. this study is the first to describe cyanobacterial lipoproteins as potential environmental immunomodulators). Moreover, the ability of cellular biosensors to be activated by intact cyanobacterial cells from blooms provides proof of concept of their direct application for environmental monitoring, especially comparison of potential threats without need for chemical analysis and identification of toxicants.

Cyanophage Distribution Across European Lakes of the Temperate-Humid Continental Climate Zone Assessed Using PCR-Based Genetic Markers.

Studies of the diversity and distribution of freshwater cyanophages are generally limited to the small geographical areas, in many cases including only one or few lakes. Data from dozens of various lakes distributed at a larger distance are necessary to understand their spatial distribution and sensitivity to biotic and abiotic factors. Thus, the objective of this study was to analyze the diversity and distribution of cyanophages within the infected cells using marker genes (psbA, nblA, and g91) in 21 Polish and Lithuanian lakes. Physicochemical factors that might be related to them were also analyzed. The results demonstrated that genetic markers representing cyanophages were observed in most lakes studied. The frequently detected gene was psbA with 88% of cyanophage-positive samples, while nblA and g91 were found in approximately 50% of lakes. The DNA sequence analyses for each gene demonstrated low variability between them, although the psbA sequences branched within the larger cluster of marine Synechoccocuss counterparts. The principal component analysis allowed to identify significant variation between the lakes that presented high and low cyanobacterial biomass. The lakes with high cyanobacterial biomass were further separated by country and the different diversity of cyanobacteria species, particularly Planktothrix agardhii, was dominant in the Polish lakes and Planktolyngbya limnetica in the Lithuanian lakes. The total phosphorous and the presence of cyanophage genes psbA and nblA were the most important factors that allowed differentiation for the Polish lakes, while the pH and the genes g91 and nblA for the Lithuanian lakes.

Are Bacterio- and Phytoplankton Community Compositions Related in Lakes Differing in Their Cyanobacteria Contribution and Physico-Chemical Properties?

Bacterioplankton community composition has become the center of research attention in recent years. Bacteria associated with toxic cyanobacteria blooms have attracted considerable interest. However, little is known about the environmental factors driving the bacteria community, including the impact of invasive cyanobacteria. Therefore, our aim has been to determine the relationships between heterotrophic bacteria and phytoplankton community composition across 24 Polish lakes with different contributions of cyanobacteria including the invasive species Raphidiopsis raciborskii. This analysis revealed that cyanobacteria were present in 16 lakes, while R. raciborskii occurred in 14 lakes. Our results show that bacteria communities differed between lakes dominated by cyanobacteria and lakes with minor contributions of cyanobacteria but did not differ between lakes with R. raciborskii and other lakes. Physical factors, including water and Secchi depth, were the major drivers of bacteria and phytoplankton community composition. However, in lakes dominated by cyanobacteria, bacterial community composition was also influenced by biotic factors such as the amount of R. raciborskii, chlorophyll-a and total phytoplankton biomass. Thus, our study provides novel evidence on the influence of environmental factors and R. raciborskii on lake bacteria communities.

In Vitro Toxicological Screening of Stable and Senescing Cultures of Aphanizomenon, Planktothrix, and Raphidiopsis.

Toxicity of cyanobacteria is the subject of ongoing research, and a number of toxic metabolites have been described, their biosynthesis pathways have been elucidated, and the mechanism of their action has been established. However, several knowledge gaps still exist, e.g., some strains produce hitherto unknown toxic compounds, while the exact dynamics of exerted toxicity during cyanobacterial growth still requires further exploration. Therefore, the present study investigated the toxicity of extracts of nine freshwater strains of Aphanizomenon gracile, an Aphanizomenon sp. strain isolated from the Baltic Sea, a freshwater strain of Planktothrix agardhii, and two strains of Raphidiopsis raciborskii obtained from 25- and 70-day-old cultures. An in vitro experimental model based on Cyprinus carpio hepatocytes (oxidative stress markers, DNA fragmentation, and serine/threonine protein activity) and brain homogenate (cholinesterase activity) was employed. The studied extracts demonstrated toxicity to fish cells, and in general, all examined extracts altered at least one or more of considered parameters, indicating that they possess, to some degree, toxic potency. Although the time from which the extracts were obtained had a significant importance for the response of fish cells, we observed strong variability between the different strains and species. In some strains, extracts that originated from 25-day-old cultures triggered more harmful effects on fish cells compared to those obtained from 70-day-old cultures, whereas in other strains, we observed the opposite effect or a lack of a significant change. Our study revealed that there was no clear or common pattern regarding the degree of cyanobacterial bloom toxicity at a given stage of development. This means that young cyanobacterial blooms that are just forming can pose an equally toxic threat to aquatic vertebrates and ecosystem functioning as those that are stable or old with a tendency to collapse. This might be largely due to a high variability of strains in the bloom.

The Effect of a Combined Hydrogen Peroxide-MlrA Treatment on the Phytoplankton Community and Microcystin Concentrations in a Mesocosm Experiment in Lake Ludos.

Harmful cyanobacteria and their toxic metabolites constitute a big challenge for the production of safe drinking water. Microcystins (MC), chemically stable hepatotoxic heptapeptides, have often been involved in cyanobacterial poisoning incidents. A desirable solution for cyanobacterial management in lakes and ponds would eliminate both excess cyanobacteria and the MC that they potentially produce and release upon lysis. Hydrogen peroxide (H2O2) has recently been advocated as an efficient means of lysing cyanobacteria in lakes and ponds, however H2O2 (at least when used at typical concentrations) cannot degrade MC in environmental waters. Therefore, mesocosm experiments combining the cyanobacteria-lysing effect of H2O2 and the MC-degrading capacity of the enzyme MlrA were set up in the highly eutrophic Lake Ludos (Serbia). The H2O2 treatment decreased the abundance of the dominant cyanobacterial taxa Limnothrix sp., Aphanizomenon flos-aquae, and Planktothrix agardhii. The intracellular concentration of MC was reduced/eliminated by H2O2, yet the reduction of the extracellular MC could only be accomplished by supplementation with MlrA. However, as H2O2 was found to induce the expression of mcyB and mcyE genes, which are involved in MC biosynthesis, the use of H2O2 as a safe cyanobacteriocide still requires further investigation. In conclusion, the experiments showed that the combined use of H2O2 and MlrA is promising in the elimination of both excess cyanobacteria and their MC in environmental waters.

Correlation between specific groups of heterotrophic bacteria and microcystin biodegradation in freshwater bodies of central Europe.

Microcystins produced by several toxic cyanobacterial strains constitute an important problem for public health. Bacterial degradation of these hepatotoxins may play an important role in natural ecosystems, however the nature of the process is very poorly understood. The aim of our study was to investigate the possible interactions between cyanotoxin producers and degraders. Samples collected from 24 water bodies in western Poland were analysed to determine the chemo-physical parameters, phytoplankton content, bacterial community structure and microcystin-biodegradation potency. A redundancy analysis identified a positive correlation between the capacity of a community to degrade microcystin LR (MC-LR) and temperature, pH, chlorophyll a concentration and the abundance of MC-producers. The relative abundance of classes F38, TM7-3 and the order WCHB1-81c (Actinobacteria) was significantly higher in the lakes with MC-biodegradation potency. Some specific bacterial genera belonging to Acidobacteria, Chloroflexi, Gemmatimonadetes, Firmicutes and TM7 were closely correlated with the occurrence of Microcystis spp. Furthermore, the MC biodegradation process was connected with the same bacterial groups. Thus, our approach allowed us to provide a broader picture of some specific relations between microcystin producers and potential microcystin degraders. A more comprehensive analysis of the existing correlations may be helpful in our understanding of natural mechanisms of MC elimination using bacteria such as MC-degraders.

A study of polymethoxy-1-alkenes in Raphidiopsis (Cylindrospermopsis) raciborskii and Aphanizomenon gracile isolated in Poland.

Previous studies indicated that teratogenic polymethoxy-1-alkenes (PMAs) are produced by phylogenetically diverse cyanobacteria taxa, however corresponding studies on the occurrence of PMAs in European cyanobacteria are lacking. Herein, the presence of PMAs in strains of Raphidiopsis raciborskii and Aphanizomenon gracile isolated from surface waters in Poland was studied using nuclear magnetic resonance and mass spectrometry. No PMAs were detected in any of the strains investigated, indicating that production of these compounds may be geographically diversified. Further studies are necessary to elucidate mechanisms of cyanobacterial PMAs synthesis.

Is the presence of Central European strains of Raphidiopsis (Cylindrospermopsis) raciborskii a threat to a freshwater fish? An in vitro toxicological study in common carp cells.

As yet European strains of Raphidiopsis raciborskii (previously Cylindrospermopsis raciborskii) have not been found to produce known cyanotoxins although their extracts have caused adverse effects in mammals, as shown using in vitro and in vivo experimental models. The present study investigated whether R. raciborskii isolated from Western Poland and Ukraine can affect fish cells using in vitro exposures of hepatocytes and red blood cells (RBC), and brain homogenates obtained from common carp (Cyprinus carpio) to 1.0% and 0.1% extracts of 7 strains. The studied extracts evoked different responses of catalase activity in hepatocytes with both increase and decrease observed under low and high concentrations. The cellular thiol pool was also altered with most extracts inducing a decrease in the activity of glutathione-S-transferase, and Ukrainian strains leading to an increase in glutathione level and a decrease in metallothionein content. All the studied extracts induced comparable reactive oxygen species formation, lipid peroxidation, protein carbonylation and DNA fragmentation in hepatocytes, and all but one increased the activity of caspase-3. Only one extract caused lysosomal membrane destabilization as measured by neutral red retention in RBC. In contrast to extracts of Ukrainian isolates, exposure of brain homogenates to extracts of Polish strains induced an increase in acetylcholinesterase activity suggesting the neurotoxic action of their exudates. The results indicate that both Polish and Ukrainian strains of R. raciborskii may pose a toxicological risk to freshwater fish, and further, that Polish strains may produce compound(s) evoking neurotoxic effects.

The structure and toxicity of winter cyanobacterial bloom in a eutrophic lake of the temperate zone.

Winter cyanobacterial blooms have become increasingly common in eutrophic lakes advocating a need for their monitoring and risk assessment. The present study evaluated the toxicity of a winter cyanobacterial bloom in a eutrophicated freshwater lake located in Western Poland. The bloom was dominated by potentially toxic species: Planktothrix agardhii, Limnothrix redekei, and Aphanizomenon gracile. The toxin analysis revealed the presence of demethylated forms of microcystin-RR and microcystin-LR in ranges of 24.6-28.7 and 6.6-7.6 µg/L, respectively. The toxicity of sampled water was further evaluated in platelet-rich plasma isolated from healthy human subjects using lipid peroxidation and lactate dehydrogenase assays. No significant adverse effects were observed. The present study demonstrates that toxicity of some winter cyanobacterial blooms in the temperate zone, like that in Lubosinskie Lake, may not exhibit significant health risks despite microcystin production.

A report of Cylindrospermopsis raciborskii and other cyanobacteria in the water reservoirs of power plants in Ukraine.

The occurrence of cyanobacteria in freshwaters attracts much attention due to its associated health threats and ecological implications. Yet data on the composition of cyanobacteria taxa and toxigenicity in some regions is still scarce. Here, we explored the occurrence of cyanobacteria and cyanotoxins in three locations in Ukraine (reservoir for Kasperivtsi Hydrothermal Power Plant and outflowing River Seret, and cooling pond of Khmelnytsky Atomic Power Plant) in summer 2017. Cyanobacteria were a dominant fraction at all stations. A number of potent-toxin producers were identified including Cylindrospermopsis raciborskii, Aphanizomenon gracile, Dolichospermum flos-aquae, and Planktothrix agardhii. Screening for the presence of dissolved and particulate content of microcystins (-LR, -YR, and -RR), cylindrospermopsin, and anatoxin-a yielded negative results. The studied waters displayed no toxicity in human platelets in vitro. Further toxicological and ecological studies are necessary to evaluate the potential presence of cyanotoxin producers in Ukraine.

Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins.

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

Distribution of invasive Cylindrospermopsis raciborskii in the East-Central Europe is driven by climatic and local environmental variables.

Mechanisms behind expansion of an invasive cyanobacterium Cylindrospermopsis raciborskii have not been fully resolved, and different hypotheses, such as global warming, are suggested. In the East-Central Europe, it is widely occurring in western part of Poland but only in single locations in the East due to some limiting factors. Therefore, broad-scale phytoplankton survey including 117 randomly selected lakes in Poland and Lithuania was conducted. The results showed that C. raciborskii occurred widely in western part of Poland but was absent from other regions and Lithuania except one lake. The regions in which C. raciborskii was present had higher annual mean air temperature, higher maximum air temperature of the warmest month and higher minimum temperature of the coldest month, demonstrating that average air temperature, and indirectly, the duration of growing season might be more important factor driving C. raciborskii distribution than measured in situ water temperature. In turn, the presence of C. raciborskii in single localities may be more related to physiological adaptations of separated ecotype. Collectively, these results provide novel evidence on the influence of temperature on C. raciborskii distribution in East-European regions but also indicate high ecological plasticity of this species.

Cylindrospermopsin Biodegradation Abilities of Aeromonas sp. Isolated from Rusalka Lake.

The occurrence of the cyanobacterial toxin cylindrospermopsin (CYN) in freshwater reservoirs is a common phenomenon. However, the biodegradation of this toxin in environmental samples has been observed only occasionally. In this work the biodegradation ability of cylindrospermopsin was investigated based on isolates from lakes with previous cyanotoxin history. Bacterial strains were identified based on the 16S rDNA and rpoD gene comparison. CYN biodegradation was monitored using the HPLC method. The R6 strain identified as Aeromonas sp. was documented as being capable of CYN removal. This biodegradation was dependent on the pH and temperature. Additionally, the stimulation of the growth of the R6 strain in the presence of CYN was indicated. Our discovery supports the hypothesis that (in analogy to the well-known phenomenon of microcystin biodegradation) in lakes dominated by potential CYN-producing cyanobacteria, the processes of microbial utilization of this toxin may occur.

Toxic potencies of metabolite(s) of non-cylindrospermopsin producing Cylindrospermopsis raciborskii isolated from temperate zone in human white cells.

Cylindrospermopsis raciborskii (Nostocales, Cyanobacteria) has worldwide distribution and is well known for producing the toxic alkaloid, cylindrospermopsin (CYN). Strains unable to synthesize this compound but potentially toxic were recently identified in Europe. Here, for the first time the effect of cell-free extracts of a non-CYN-producing strain of C. raciborskii was studied in human cells (neutrophils and lymphocytes) isolated from healthy donors. The observed effects were compared to those induced by CYN (1.0-0.01 µg mL(-1)). Short-term (1h) extract treatments resulted in altered viability of cells demonstrated by increased necrosis and apoptosis in neutrophils and elevated apoptosis in lymphocytes. CYN did not induce similar effects, regardless of the toxin concentration. Exposure of T-lymphocytes to 100% C. raciborskii extract in isolated and whole-blood 72 h cultures resulted in decrease of proliferation by 20.6% and 32.5%, respectively. In comparison, exposure to 1.0 µg mL(-1) of CYN caused lymphocytes proliferation to be inhibited by 91.0% in isolated cultures and 56.5% in whole-blood assay. Significant antiproliferative properties were also found for 0.1 µg mL(-1) of CYN in whole-blood culture. From the results we conclude that strains occurring in temperate zones may pose a threat to human health through the production of hitherto unknown metabolites that reveal a toxic pattern different to that of CYN. At the same time our study demonstrates that CYN is a powerful but slowly-acting toxin in human immune cells.

Bioaccumulation of metals and metalloids in medicinal plant Ipomoea pes-caprae from areas impacted by tsunami.

Tsunami events may have an enormous impact on the functioning of aquatic and terrestrial ecosystems by altering various relationships with biotic components. Concentrations of acid-leachable fractions of heavy metals and metalloids in soils and plant samples from areas affected by the December 2004 tsunami in Thailand were determined. Ipomoea pes-caprae, a common plant species growing along the seashore of this region, and frequently used in folk medicine, was selected to assess the presence of selected elements. Elevated amounts of Cd, Pb, Zn, and As in soil samples, and Pb, Zn, As, Se, Cr, and Ni in plant samples were determined from the tsunami-impacted regions for comparison with reference locations. The flowers of Ipomoea pes-caprae contained the highest amounts of these metals, followed by its leaves, and stems. In addition, its bioaccumulation factor (BAF) supports this capability of high metal uptake by Ipomoea pes-caprae from the areas affected by the tsunami in comparison with a reference site. This uptake was followed by the translocation of these elements to the various plant components. The presence of these toxic metals in Ipomoea pes-caprae growing in contaminated soils should be a concern of those who use this plant for medicinal purposes. Further studies on the content of heavy metals and metalloids in this plant in relation to human health concerns are recommended.

Aphanizomenon gracile (Nostocales), a cylindrospermopsin-producing cyanobacterium in Polish lakes.

The cyanobacterial cytotoxin cylindrospermopsin (CYN) has become increasingly common in fresh waters worldwide. It was originally isolated from Cylindrospermopsis raciborskii in Australia; however, in European waters, its occurrence is associated with other cyanobacterial species belonging to the genera Aphanizomenon and Anabaena. Moreover, cylindrospermopsin-producing strains of widely distributed C. raciborskii have not yet been observed in European waters. The aims of this work were to assess the occurrence of CYN in lakes of western Poland and to identify the CYN producers. The ELISA tests, high-performance liquid chromatography (HPLC)-DAD, and HPLC-mass spectrometry (MS)/MS were conducted to assess the occurrence of CYN in 36 lakes. The cyrJ, cyrA, and pks genes were amplified to identify toxigenic genotypes of cyanobacteria that are capable of producing CYN. The toxicity and toxigenicity of the C. raciborskii and Aphanizomenon gracile strains isolated from the studied lakes were examined. Overall, CYN was detected in 13 lakes using HPLC-MS/MS, and its concentrations varied from trace levels to 3.0 µg L(-1). CYN was widely observed in lakes of western Poland during the whole summer under different environmental conditions. Mineral forms of nutrients and temperature were related to CYN production. The molecular studies confirmed the presence of toxigenic cyanobacterial populations in all of the samples where CYN was detected. The toxicity and toxigenicity analyses of isolated cyanobacteria strains revealed that A. gracile was the major producer of CYN.

Cylindrospermopsin: water-linked potential threat to human health in Europe.

Cylindrospermopsin (CYN) is a secondary metabolite produced by several cyanobacteria species. Its potential effect on human health includes liver, kidneys, lungs, spleen and intestine injuries. CYN can be cyto- and genotoxic to a variety of cell types. Occurrence and expansion of species able to synthesize CYN in European water bodies has been recently reported and raised awareness of potential harm to human health. Therefore, surface water of different human use should be monitored for the presence of toxic species of blue-green algae. This paper aims to describe the distribution of CYN producers in Europe and the potential effects of the toxin on human health according to the current state of knowledge.