The Experts below are selected from a list of 1782 Experts worldwide ranked by ideXlab platform
Kaarina Sivonen - One of the best experts on this subject based on the ideXlab platform.
-
Table7.XLSX
2018Co-Authors: Jonna E. Teikari, Matti Wahlsten, Shengwei Hou, Wolfgang R. Hess, Kaarina SivonenAbstract:Salinity is an important abiotic factor controlling the distribution and abundance of Nodularia spumigena, the dominating diazotrophic and toxic phototroph, in the brackish water cyanobacterial blooms of the Baltic Sea. To expand the available genomic information for brackish water cyanobacteria, we sequenced the isolate Nodularia spumigena UHCC 0039 using an Illumina-SMRT hybrid sequencing approach, revealing a chromosome of 5,294,286 base pairs (bp) and a single plasmid of 92,326 bp. Comparative genomics in Nostocales showed pronounced genetic similarity among Nodularia spumigena strains evidencing their short evolutionary history. The studied Baltic Sea strains share similar sets of CRISPR-Cas cassettes and a higher number of insertion sequence (IS) elements compared to Nodularia spumigena CENA596 isolated from a shrimp production pond in Brazil. Nodularia spumigena UHCC 0039 proliferated similarly at three tested salinities, whereas the lack of salt inhibited its growth and triggered transcriptome remodeling, including the up-regulation of five sigma factors and the down-regulation of two other sigma factors, one of which is specific for strain UHCC 0039. Down-regulated genes additionally included a large genetic region for the synthesis of two yet unidentified natural products. Our results indicate a remarkable plasticity of the Nodularia salinity acclimation, and thus salinity strongly impacts the intensity and distribution of cyanobacterial blooms in the Baltic Sea.
-
Image8.PDF
2018Co-Authors: Jonna E. Teikari, Matti Wahlsten, Shengwei Hou, Wolfgang R. Hess, Kaarina SivonenAbstract:Salinity is an important abiotic factor controlling the distribution and abundance of Nodularia spumigena, the dominating diazotrophic and toxic phototroph, in the brackish water cyanobacterial blooms of the Baltic Sea. To expand the available genomic information for brackish water cyanobacteria, we sequenced the isolate Nodularia spumigena UHCC 0039 using an Illumina-SMRT hybrid sequencing approach, revealing a chromosome of 5,294,286 base pairs (bp) and a single plasmid of 92,326 bp. Comparative genomics in Nostocales showed pronounced genetic similarity among Nodularia spumigena strains evidencing their short evolutionary history. The studied Baltic Sea strains share similar sets of CRISPR-Cas cassettes and a higher number of insertion sequence (IS) elements compared to Nodularia spumigena CENA596 isolated from a shrimp production pond in Brazil. Nodularia spumigena UHCC 0039 proliferated similarly at three tested salinities, whereas the lack of salt inhibited its growth and triggered transcriptome remodeling, including the up-regulation of five sigma factors and the down-regulation of two other sigma factors, one of which is specific for strain UHCC 0039. Down-regulated genes additionally included a large genetic region for the synthesis of two yet unidentified natural products. Our results indicate a remarkable plasticity of the Nodularia salinity acclimation, and thus salinity strongly impacts the intensity and distribution of cyanobacterial blooms in the Baltic Sea.
-
production of high amounts of hepatotoxin nodularin and new protease inhibitors pseudospumigins by the brazilian benthic nostoc sp cena543
Frontiers in Microbiology, 2017Co-Authors: Jouni Jokela, Lassi Matti Petteri Heinila, Tânia K Shishido, Matti Wahlsten, David P Fewer, Marli Fatima Fiore, Hao Wang, Esa Haapaniemi, Perttu Permi, Kaarina SivonenAbstract:Nostoc is cyanobacterial genus, common in soils and a prolific producer of natural products. This research project aimed to explore Brazilian cyanobacteria for new bioactive compounds and their characterization. Here we report the production of hepatotoxins and new protease inhibitors from benthic Nostoc sp. CENA543 isolated from small, shallow, saline-alkaline lake in the Nhecolândia, Pantanal wetland area in Brazil. Nostoc sp. CENA543 produces exceptionally high amounts of nodularin-R. This is the first free-living Nostoc found that produce nodularin at comparable levels as the toxic, bloom-forming, Nodularia spumigena. We also found and characterized pseudospumigins A-F, which are a novel family of linear tetrapeptides. Pseudospumigins are structurally related to linear tetrapeptide spumigins and aeruginosins both present in N. spumigena but differ in respect to their diagnostic amino acid which is Ile/Leu/Val in pseudospumigins, Pro/mPro in spumigins and Choi in aeruginosins. The pseudospumigin gene cluster is more similar to the spumigin biosynthetic gene cluster than the aeruginosin gene cluster. Pseudospumigin A inhibited trypsin (IC50 4.5 μM after 1 h) in a similar manner as spumigin E from N. spumigena but was almost two orders of magnitude less potent. This study identifies another location and environment where the hepatotoxic nodularin has the potential to cause deaths of eukaryotic organisms.
-
Allelopathy of Baltic Sea cyanobacteria: No evidence for the role of nodularin
2016Co-Authors: Sanna Suikkanen, Jouni Jokela, Kaarina Sivonen, Markku ViitasaloAbstract:Extracts of Aphanizomenon flos-aquae and Nodularia spumigena, the two most common cyano-bacteria forming recurrent blooms in the Baltic Sea, decrease the abundance of some phytoplankton species via the release of allelopathic substances. We investigated how cell-free filtrates of the two cyanobacteria, as well as purified hepatotoxin nodularin, produced by N. spumigena affected cell numbers, chlorophyll a content and 14CO2 uptake of the cryptophyte Rhodomonas sp. Both cyanobacterial filtrates significantly retarded the growth of Rhodomonas sp., A. flos-aquae filtrate up to 46%, whereas purified nodularin showed no significant effect on any of the growth parameters of the cryptophyte. These results suggest that the allelopathic effect of N. spumigena is most probably due to metabolite(s) other than nodularin, possibly acting via the damage of the target cells
-
Insights into the Physiology and Ecology of the Brackish- Water-Adapted Cyanobacterium Nodularia spumigena CCY9414 Based on a Genome-Transcriptome Analysis
2016Co-Authors: Henk Bolhuis, Kaarina Sivonen, Birgitta Bergman, David P Fewer, Rehab El-shehawy, Matthias Kopf, Fabian Haas, Paul Hayes, Elke Dittmann, Dave J. ScanlanAbstract:Nodularia spumigena is a filamentous diazotrophic cyanobacterium that dominates the annual late summer cyanobacterial blooms in the Baltic Sea. But N. spumigena also is common in brackish water bodies worldwide, suggesting special adaptation allowing it to thrive at moderate salinities. A draft genome analysis of N. spumigena sp. CCY9414 yielded a single scaffold of 5,462,271 nucleotides in length on which genes for 5,294 proteins were annotated. A subsequent strand-specific transcriptome analysis identified more than 6,000 putative transcriptional start sites (TSS). Orphan TSSs located in intergenic regions led us to predict 764 non-coding RNAs, among them 70 copies of a possible retrotransposon and several potential RNA regulators, some of which are also present in other N2-fixing cyanobacteria. Approximately 4 % of the total coding capacity is devoted to the production of secondary metabolites, among them the potent hepatotoxin nodularin, the linear spumigin and the cyclic nodulapeptin. The transcriptional complexity associated with genes involved in nitrogen fixation and heterocyst differentiation is considerably smaller compared to other Nostocales. In contrast, sophisticated systems exis
Harri Kankaanpää - One of the best experts on this subject based on the ideXlab platform.
-
Oxidative stress response in the red alga Furcellaria lumbricalis (Huds.) Lamour. due to exposure and uptake of the cyanobacterial toxin nodularin from Nodularia spumigena.
Harmful Algae, 2010Co-Authors: Stephan Pflugmacher, Miikka Olin, Harri KankaanpääAbstract:The phenomenon of cyanobacterial blooms in the Baltic Sea is getting very common during the last few years. These blooms mostly consist of Nodularia species which can be toxic, producing nodularins. As some of these blooms are wind driven to the coastline, an influence of the aquatic flora, especially on the macroalgae is expected. One of these common macroalgae is the red alga Furcellaria lumbricalis, living on hard bottom substrates in the lower part of the phytobenthic zone. Uptake of nodularin into red alga the generation of oxidative stress, respectively the antioxidative response is shown measuring the activity of several antioxidative enzymes. The uptake of nodularins by the red alga is shown. The toxins caused oxidative stress in the algae and induced an antioxidative defence.
-
production and sedimentation of peptide toxins nodularin r and microcystin lr in the northern baltic sea
Environmental Pollution, 2009Co-Authors: Harri Kankaanpää, Olli Sjovall, Miikka Olin, Krister Karlsson, Maija Huttunen, Kirsi Hyvarinen, Laura Sneitz, Janne HarkonenAbstract:This seven-year survey was primarily targeted to quantification of production of nodularin-R (NOD-R), a cyclic pentapeptide hepatotoxin, in Baltic Sea cyanobacteria waterblooms. Additionally, NOD-R and microcystin-LR (MC-LR; a cyclic heptapeptide toxin) sedimentation rates and NOD-R sediment storage were estimated. NOD-R production (70-2450 microg m(-3); approximately 1 kg km(-2) per season) and sedimentation rates (particles; 0.03-5.7 microg m(-2)d(-1); approximately 0.3kg km(-2) per season) were highly variable over space and time. Cell numbers of Nodularia spumigena did not correlate with NOD-R quantities. Dissolved NOD-R comprised 57-100% of total NOD-R in the predominantly senescent, low-intensity phytoplankton blooms and seston. Unprecedentedly intensive MC-LR sedimentation (0.56 microg m(-2)d(-1)) occurred in 2004. Hepatotoxin sedimentation rates highly exceeded those of anthropogenic xenobiotics. NOD-R storage in surficial sediments was 0.4-20 microg kg(-1) ( approximately 0.1 kg km(-2)). Loss of NOD-R within the chain consisting of phytoplankton, seston and soft sediments seemed very effective.
-
accumulation and depuration of cyanobacterial toxin nodularin and biomarker responses in the mussel mytilus edulis
Chemosphere, 2007Co-Authors: Harri Kankaanpää, Olli Sjovall, Sari Leinio, Miikka Olin, Kari K. LehtonenAbstract:Blue mussels (Mytilus edulis) were exposed to an extract made of natural cyanobacterial mixture containing toxic cyanobacterium Nodularia spumigena (70–110 lg nodularin l � 1 , 24-h exposure followed by 144-h depuration period in clean water). Toxin concentration increased from initial 400 to 1100 mg kg � 1 after 24-h exposure, measured by liquid chromatography/mass spectrometry (LC/MS). Acetylcholinesterase activity (AChE), a biomarker of direct neurotoxic effects, showed inhibition after 12 and 24 h exposure but returned to control level during the depuration period. Catalase (CAT) activity, an indicator of oxidative stress, showed significantly elevated levels in exposed mussels but only 72 h after the end of the exposure. No change in the activity of glutathione-S-transferase (GST) involved in conjugation reactions could be observed. A gradual yet incomplete elimination of nodularin (from 1100 to 600 mg kg � 1 ) was observed during the depuration period, and the tissue levels were 30% lower in clean water after 24 h. The observed increase in oxidative stress indicated by elevated CAT activity is likely connected to detoxification reactions leading to the production of reactive oxygen species, including an apparent time lag in this specific enzymatic defence response. That no change in GST activity was observed suggests that this enzyme is not significantly involved in the detoxification process of nodularin-containing cyanobacterial extract in M. edulis. � 2007 Elsevier Ltd. All rights reserved.
-
transfer of nodularin to three spined stickleback gasterosteus aculeatus l herring clupea harengus l and salmon salmo salar l in the northern baltic sea
Ecotoxicology and Environmental Safety, 2007Co-Authors: Harri Kankaanpää, Heikki Peltonen, M VinniAbstract:Abstract Nodularin (NODLN) is a hepatotoxin produced by the cyanobacterium Nodularia spumigena, which occurs regularly in the Baltic Sea. The primary aim of this study was to study the transfer of NODLN to three-spined stickleback (Gasterosteus aculeatus L.), herring (Clupea harengus membras L.), and salmon (Salmo salar L.), which were caught from the northern Baltic Sea between August 2002 and August 2003. Liquid chromatography mass spectrometry (LC-MS) was used for NODLN analysis. NODLN was found in both herring (0–90 μg kg−1 dw) and three-spined sticklebacks samples (2.8–700 μg kg−1 dw). The recovery for the spiked stickleback samples in vitro was 28%. Only 1 salmon of a total of 10 contained a small amount of NODLN (10 μg kg−1 dw). However, the high concentrations in individual stickleback suggest that possible transfer to higher trophic levels deserves more research.
-
Nodularin induces oxidative stress in the Baltic Sea brown alga Fucus vesiculosus (Phaeophyceae)
Marine environmental research, 2007Co-Authors: Stephan Pflugmacher, Miikka Olin, Harri KankaanpääAbstract:Abstract In the Baltic Sea regular, intensive cyanobacterial blooms rich in the cyanobacterium Nodularia spumigena occur during the summer season. N. spumigena is known to produce the cyclic pentapeptide nodularin (NOD) in high concentrations. Marine macroalgae, together with sea-grass meadows, are an extremely important habitat for life in the sea. In addition to this, the decaying macroalgae substantially contribute to the substrate for the microbial loop in coastal food webs. Uptake of nodularin into the brown macroalga Fucus vesiculosus was assessed using an ELISA technique resulting in an uptake of up to 45.1 μg kg−1 fresh weight (fw). Nodularin was also detected in the reproductive part of the algae (receptacle) at 14.1 μg kg−1 fw. The induction of oxidative stress in F. vesiculosus, after exposure to NOD, was also shown by monitoring cellular damage as changes in lipid peroxidation and the activation of antioxidative defence systems (antioxidative capacity, superoxide dismutase and soluble glutathione S-transferase).
Markku Viitasalo - One of the best experts on this subject based on the ideXlab platform.
-
Allelopathy of Baltic Sea cyanobacteria: No evidence for the role of nodularin
2016Co-Authors: Sanna Suikkanen, Jouni Jokela, Kaarina Sivonen, Markku ViitasaloAbstract:Extracts of Aphanizomenon flos-aquae and Nodularia spumigena, the two most common cyano-bacteria forming recurrent blooms in the Baltic Sea, decrease the abundance of some phytoplankton species via the release of allelopathic substances. We investigated how cell-free filtrates of the two cyanobacteria, as well as purified hepatotoxin nodularin, produced by N. spumigena affected cell numbers, chlorophyll a content and 14CO2 uptake of the cryptophyte Rhodomonas sp. Both cyanobacterial filtrates significantly retarded the growth of Rhodomonas sp., A. flos-aquae filtrate up to 46%, whereas purified nodularin showed no significant effect on any of the growth parameters of the cryptophyte. These results suggest that the allelopathic effect of N. spumigena is most probably due to metabolite(s) other than nodularin, possibly acting via the damage of the target cells
-
Nodularin concentrations in Baltic Sea zooplankton and fish during a cyanobacterial bloom
Marine Biology, 2008Co-Authors: Miina Karjalainen, Jari-pekka Pääkkönen, Heikki Peltonen, Terhi Valtonen, Markku ViitasaloAbstract:Toxic cyanobacterial blooms, dominated by Nodularia spumigena , are a recurrent phenomenon in the Baltic Sea during late summer. Nodularin, a potent hepatotoxin, has been previously observed to accumulate on different trophic levels, in zooplankton, mysid shrimps, fish as well as benthic organisms, even in waterfowl. While the largest concentrations of nodularin have been measured from the benthic organisms and the food web originating from them, the concentrations in the pelagic organisms are not negligible. The observations on concentrations in zooplankton and planktivorous fish are sporadic, however. A field study in the Gulf of Finland, northern Baltic Sea, was conducted during cyanobacterial bloom season where zooplankton (copepod Eurytemora affinis , cladoceran Pleopsis polyphemoides ) and fish (herring, sprat, three-spined stickleback) samples for toxin analyses were collected from the same sampling areas, concurrently with phytoplankton community samples. N. spumigena was most abundant in the eastern Gulf of Finland. In this same sampling area, cladoceran P. polyphemoides contained more nodularin than in the other areas, suggesting that this species has a low capacity to avoid cyanobacterial exposure when the abundance of cyanobacterial filaments is high. In copepod E. affinis nodularin concentrations were high in all of the sampling areas, irrespective of the N. spumigena cell numbers. Furthermore, nodularin concentrations in herring samples were highest in the eastern Gulf of Finland. Three-spined stickleback contained the highest concentrations of nodularin of all the three fish species included in this study, probably because it prefers upper water layers where also the risk of nodularin accumulation in zooplankton is the highest. No linear relationship was found between N. spumigena abundance and nodularin concentration in zooplankton and fish, but in the eastern area where the most dense surface-floating bloom was observed, the nodularin concentrations in zooplankton were high. The maximum concentrations in zooplankton and fish samples in this study were higher than measured before, suggesting that the temporal variation of nodularin concentrations in pelagic communities can be large, and vary from negligible to potentially harmful.
-
physiological effects in juvenile three spined sticklebacks feeding on toxic cyanobacterium Nodularia spumigena exposed zooplankton
Journal of Fish Biology, 2008Co-Authors: J P Paakkonen, Miina Karjalainen, S Ronkkonen, Markku ViitasaloAbstract:Feeding rate, growth and nutritional condition as well as nodularin concentration of juvenile three-spined sticklebacks Gasterosteus aculeatus were assessed in an experimental study where field-collected fish were given a diet of zooplankton fed with toxic Nodularia spumigena for 15 days. Food consumption was higher in N. spumigena bloom conditions compared with the cyanobacterium-free control, but despite this the growth rate of exposed fish did not improve. Control fish and fish fed N. spumigena-exposed zooplankton had higher RNA:DNA ratios and protein content than fish grown in cyanobacterial bloom conditions indicating good nutritional condition and recent growth of fish, whereas in bloom conditions metabolic transformation of nodularin to less toxic compounds may cause an energetic cost to the fish affecting the growth rate of the whole organism. Juvenile three-spined sticklebacks collected from the field contained higher concentrations of nodularin at the beginning of the experiment (mean 503·1 μg kg−1). After 15 days, the lowest nodularin concentrations in fish were measured in the control treatment, suggesting that fish fed with non-toxic food are able to detoxify nodularin from their tissues more effectively than fish in continuing exposure.
-
Nodularin accumulation during cyanobacterial blooms and experimental depuration in zooplankton
Marine Biology, 2006Co-Authors: Miina Karjalainen, Maiju Lehtiniemi, Harri Kankaanpää, Betina Kozlowsky-suzuki, Jonna Engström-Öst, Markku ViitasaloAbstract:Cyanobacterial blooms are a common phenomenon in the Baltic Sea, and the hepatotoxin nodularin has been frequently detected in certain Baltic Sea fishes and mussels. However, there is no knowledge about the naturally occurring concentrations of nodularin in Baltic Sea zooplankton. The aim of this study was to survey the concentrations of nodularin in natural zooplankton assemblages, and to study the depuration of nodularin in one common copepod species, Eurytemora affinis , experimentally. The nodularin concentrations in common zooplankton species were determined from field-collected samples from the northern Baltic Proper in 2001 and 2002, during cyanobacterial blooms, and the samples were analysed by ELISA immunoassay. Nodularin could be detected from the field-collected zooplankton, suggesting that during a natural bloom event toxins accumulate in their tissues. The concentrations were relatively low (0.07±0.01 μg g^−1 ww), ranging from below detection limit to 0.62 μg g^−1 ww. Some variation occurred in the concentrations between species and years; generally concentrations were higher in 2001 than in 2002. In the depuration experiment E. affinis copepods were fed with toxic Nodularia spumigena for 24 h, and their toxin contents were monitored for 24 h after transferring them to filtered seawater. A rapid decrease in nodularin concentrations occurred during the first 0.5–3 h after the exposure. However, after a 24-h depuration period in filtered seawater, nodularin could be still detected in E. affinis tissues, indicating that part of the accumulated nodularin, or its derivatives, could be transferred to planktivores.
-
does cyanobacterial toxin accumulate in mysid shrimps and fish via copepods
Journal of Experimental Marine Biology and Ecology, 2002Co-Authors: Jonna Engstromost, Sandra Green, Betina Kozlowskysuzuki, Maiju Lehtiniemi, Markku ViitasaloAbstract:It has been suggested that pelagic planktivores may receive cyanobacterial toxins indirectly, i.e., by preying on organisms that have ingested cyanobacteria. We tested this hypothesis in laboratory conditions by providing mysid shrimps, Mysis relicta, and three-spined sticklebacks, Gasterosteus aculeatus, with cyanobacteria-fed copepods. The aim of the study was to observe the potential transfer and accumulation of the toxin nodularin, produced by the cyanobacteria Nodularia spumigena, in planktivore tissue during the 10-day trials. The concentration of nodularin was measured by two toxin detection methods, enzyme-linked immunosorbent assay (ELISA) and protein phosphatase (PPase) inhibition assay. The ELISA results showed that the toxin concentrations in mysid tissue were significantly higher than in fish tissue, whereas no differences between species were detected by PPase inhibition assay. The concentrations measured by ELISA suggested that accumulation had taken place in mysids, since the toxin increased with time in the animals. The concentrations, measured by PPase inhibition assay, were significantly higher than the ones measured by ELISA. We conclude that cyanobacterial toxin may accumulate in higher trophic levels via copepods and that the results are more reliable if analysed with several methods.
Susan I Blackburn - One of the best experts on this subject based on the ideXlab platform.
-
correlation of the content of hepatotoxin nodularin and glycosidic carotenoids 4 ketomyxol 2 fucoside and novel 1 o methyl 4 ketomyxol 2 fucoside in 20 strains of the cyanobacterium Nodularia spumigena
Biochemical Systematics and Ecology, 2008Co-Authors: Louise Schluter, Bjart Frode Lutnaes, Synnove Liaaenjensen, Kristine Garde, Hanne Kaas, Ian Jameson, Susan I BlackburnAbstract:The carotenoids of 19 different strains of Nodularia spumigena and one Nodularia sphaerocarpa from different global locations were investigated. The molecular structure of the diagnostic pigment in N. spumigena of the Baltic Sea, tentatively named ‘4-keto-myxoxanthophyll-like pigment’ in Schluter, L., Garde, K., Kaas, H., [2004. A 4-keto-myxoxanthophyll-like pigment is a diagnostic pigment for the toxic cyanobacteria Nodularia spumigena in the Baltic Sea. Mar. Ecol. Prog. Ser. 275, 69–78.] was determined to be a 4-ketomyxol-2′-fucoside. In most of the strains an additional carotenoid was found, identified as the novel 1′-O-methyl-4-ketomyxol-2′-fucoside by 2D NMR. This glycosidic carotenoid methyl ether was found to be a more important diagnostic pigment than the 4-ketomyxol-2′-fucoside for the toxic N. spumigena in the Baltic Sea. Out of the 20 strains 15 were found to produce the hepatotoxin nodularin. The content of carotenoids and nodularin was found to increase relative to chlorophyll a at increasing light intensity and at stationary growth, and nodularin was significantly correlated to both 4-ketomyxol-2′-fucoside and 1′-O-methyl-4-ketomyxol-2′-fucoside, and particular to the sum of these two pigments.
-
rrna sequences reflect the ecophysiology and define the toxic cyanobacteria of the genus Nodularia
International Journal of Systematic and Evolutionary Microbiology, 2001Co-Authors: Michelle C. Moffitt, Susan I Blackburn, Brett A. NeilanAbstract:Nodularia, a member of the order Nostocales, is a bloom-forming filamentous cyanobacterium that possesses the ability to form toxic blooms. The toxin produced by Nodularia, nodularin, is a hepatotoxin, similar in structure to the heptapeptide toxin microcystin. Twenty-one strains of Nodularia, representing the species Nodularia spumigena, Nodularia harveyana and Nodularia sphaerocarpa, were analysed for toxin production by protein phosphatase inhibition assay and sequenced over the 16S rDNA region. Phylogenetic analysis of Nodularia 16S rDNA sequences found that Nodularia clustered into two main groups. An N. spumigena cluster was distinct from the benthic species N. harveyana and N. sphaerocarpa. There was no distinction between strains isolated from globally diverse locations. Nodularin-producing species were restricted to the single, evolutionally distinct cluster of N. spumigena. This observation has enabled the design of a specific 16S rRNA PCR for the rapid detection of nodularin-producing strains. Alignment of 16S rDNA sequences from toxic and non-toxic Nodularia with other members of the cyanobacteria allowed the design of both Nodularia generic and toxic N. spumigena-specific primers.
-
genetic morphological and toxicological variation among globally distributed strains of Nodularia cyanobacteria
Journal of Phycology, 1999Co-Authors: Christopher J S Bolch, Gary J. Jones, Philip T Orr, Susan I BlackburnAbstract:Morphological, toxicological, and genetic variation was examined among 19 strains of Nodularia. The strains examined could be morphologically discriminated into four groups corresponding to N. spumigena Mertens, N. sphaerocarpa Bornet et Flahault, and two strains that did not clearly correspond to currently accepted Nodularia species. Genetic variation was examined using nucleotide sequencing of the phycocyanin intergenic spacer region (cpcBA-IGS) and RAPD-PCR. The PCR-RFLP of the cpcBA-IGS differentiated four genotypes corresponding to the four morphological groups. However, nucleotide sequencing of 598 bp of the 690-bp fragment showed that one of the three strains corresponding to N. sphaerocarpa (PCC 7804) was genetically divergent from the other two, suggesting that it constitutes a distinct species. Nucleotide variation within the morphospecies groups was limited (<1%), and all 14 Australian strains of N. spumigena possessed identical cpcBA-IGS sequences. The RAPD-PCR differentiated the same groups as the cpcBA sequencing and discriminated each of the seven different Australian populations of N. spumigena. Strains from within a bloom appeared genetically identical; however, strains isolated from different blooms could be separated into either a western or a southeastern Australian cluster, with one strain from western Australia showing considerable genetic divergence. The pattern of variation suggests that individual blooms of N. spumigena are clonal but also that Australian N. spumigena populations are genetically distinct from each other. Examination of genetic distance within and between blooms and within and between morphological groups showed clear genetic dicontinuities that, in combination with the cpcBA-IGS data, suggest that Nodularia contains genetically distinct morphospecies rather than a continuous cline of genetic variation. Furthermore, these morphospecies are genetically variable, exhibiting hierarchical patterns of genetic variation on regional and global scales. Production of the hepatotoxin nodularin was not restricted to one genetic lineage but was distributed across three of the five genotypic groups. A strain of N. spumigena from a nontoxic Australian population was found to fall within the range of genetic variation for other toxic Australian strains and appears to be a unique nontoxic strain that might have arisen by loss of toxin production capacity.
-
effect of salinity on growth and toxin production in cultures of the bloom forming cyanobacterium Nodularia spumigena from australian waters
Phycologia, 1996Co-Authors: Susan I Blackburn, Malcolm A Mccausland, Christopher J S Bolch, Stuart J Newman, Gary J. JonesAbstract:Nodularia spumigena Mertens blooms in a number of Australia's estuarine systems and coastal embayments. We investigated the effect of four salinities between fresh water (0 g kg -1) and sea water (35 g kg -1) on growth rate, cell yield, cell dry weight and toxicity of strains isolated from three Australian populations and studied under controlled environmental conditions in the laboratory. Growth rates were significantly lower at 0 g kg-1 than at the higher salinities, and cell yields at 0 and 35 g kg-1 were lower than at 12 and 24 g kg-1 salinity. This indicates that salinity extremes do not favour W. spumigena bloom development. Salinity affected nodularin content in the logarithmic phase of growth: as salinity increased, toxin content decreased, on both a dry weight and a per cell basis. In the stationary phase of growth, nodularin content was lowest at 35 g kg-1 salinity. It increased significantly between logarithmic and stationary phases of growth. Cell mass (dry weight per cell) was not affected by growth phase. Our results indicate that mature blooms will be more toxic than developing ones because of their greater biomass and higher toxin content (on both dry weight and per cell bases).
-
A toxic bloom of Nodularia spumigena mertens in orielton lagoon, tasmania
Marine and Freshwater Research, 1994Co-Authors: Gary J. Jones, Susan I Blackburn, Naomi S. ParkerAbstract:A bloom of Nodularia spumigena Mertens occurred in Orielton Lagoon, Tasmania, a shallow, eutrophic coastal embayment, between December 1992 and March 1993. The N. spumigena bloom was preceded by a eustigmatophyte bloom and was followed in March-April 1993 by a bloom of the diatoms Nitzschia closterium (Ehrenb.) Smith and Chaetoceros socialis Lauder. The Nodularia spumigena bloom may have been stimulated by low salinity (15-20 g kg-1) in the lagoon during December and January. Culture experiments with N. spumigena strains isolated from the lagoon showed best growth at salinities between 0 and 24 g kg-1 and less optimal growth at a salinity of 35 g kg-1. Akinete production in culture was positively correlated (P lt 0.001) with increasing salinity of growth media. The collapse of the N. spumigena population may have been triggered by decreasing water temperature in March, although this cannot be conclusively proven with the limited physico-chemical data available. High-performance liquid chromatographic (HPLC) analyses of bloom samples showed high concentrations (2000-3500 mu-g g-1 dry weight) of the cyclic pentapeptide hepatotoxin nodularin in samples collected during the peak of the N. spumigena bloom in January and February. Nodularin content of the bloom decreased as the population declined, owing to the decrease in abundance of N. spumigena and the release of nodularin by dying cells. A culture of N. spumigena isolated from Orielton Lagoon produced nodularin at concentrations comparable to those observed in field samples. A second HPLC peak, eluting very close to nodularin and with a similar ultraviolet spectrum, was observed in some field samples. This compound may be the ADDA-C8 stereoisomer of nodularin.
Hanna Mazurmarzec - One of the best experts on this subject based on the ideXlab platform.
-
biodegradation of nodularin and other nonribosomal peptides by the baltic bacteria
International Biodeterioration & Biodegradation, 2018Co-Authors: Anna Torunskasitarz, Hanna Mazurmarzec, Ewa KotlarskaAbstract:Abstract Microcystins (MCs) and nodularin (NOD), the hepatotoxic nonribosomal peptides (NRPs) produced by cyanobacteria, are considered as natural pollutants of many aquatic ecosystems. Removal of the toxins proceeds mainly through biodegradation and/or photolysis. In this study, microbial degradation of NOD and other NRPs produced by Nodularia spumigena was investigated. Both, natural bacterial consortia and individual strains from the Southern Baltic Sea were used. Bacterial samples were also screened for the presence of mlrA-D genes, previously proved to be involved in the enzymatic breakdown of hepatotoxic cyanopeptides. The Baltic sediments, with natural bacterial consortia, showed NOD-degrading activity throughout the whole year. These samples were also active against other NRPs: anabaenopeptins and spumigins. The time required for NOD biodegradation ranged from 3 to 41 days and depended on the NOD content in the collected sediments. NOD-degrading activity was also revealed in the presence of ten bacterial strains isolated from sediments and three strains isolated from filaments of N. spumigena CCNP1401. The mlrA-D genes were not found in sediments and only individual genes from the entire mlr cluster were detected in five isolated bacteria. The results suggest that in the case of Baltic bacteria other genes are involved in the biosynthesis of NOD-degrading enzymes.
-
effect of crude extracts from Nodularia spumigena on round goby neogobius melanostomus
Marine Environmental Research, 2018Co-Authors: Ilona Zloch, Agnieszka Hebel, Hanna MazurmarzecAbstract:Abstract Nodularia spumigena is a nitrogen-fixing filamentous cyanobacteria in the Baltic Sea. Nodularin (NOD), the hepatotoxic peptide produced by this cyanobacterium, accumulates in the organisms from different trophic levels. In this paper, the effects of N. spumigena cell extract on the round goby (Neogobius melanostomus) was investigated under laboratory conditions. This benthic fish species feed on mussels in which nodularin accumulation was well documented. In current study a sharp increase in the NOD concentration in analyzed organs was observed after 24 h (PPIA) after 72 h of exposure (LC/MS). To determine the direction and strength of the changes induced in the fish by the toxin, several biochemical markers of exposure such as concentration of glutathione and activities of catalase, guaiacol peroxidase and glutathione S-transferase were used. In analyzed organs (liver, gills and muscle) of the round goby, the activity of these enzymes were suppressed. Higher GSH/protein amount and CAT and POD activity in gills than in liver reflects the importance of gills in NOD entering into analyzed fish body when exposed to toxin. The results indicate that the round goby (Neogobius melanostomus) exposed to extracts from N. spumigena cells triggered a defense system in a time-dependent manner. The obtained results contribute to a better understanding of fish response to the presence of compounds produced by N. spumigena.
-
Nodularia spumigena peptides accumulation and effect on aquatic invertebrates
Toxins, 2015Co-Authors: Hanna Mazurmarzec, Katarzyna Sutryk, Agnieszka Hebel, Natalia Hohlfeld, Anna Pietrasik, Agata BlaszczykAbstract:Thus far, the negative effects of Nodularia spumigena blooms on aquatic organisms have been mainly attributed to the production of the hepatotoxic nodularin (NOD). In the current work, the accumulation of other N. spumigena metabolites in blue mussels and crustaceans, and their effect on Thamnocephalus platyurus and Artemia franciscana, were examined. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses provided evidence that both blue mussels collected after a cyanobacterial bloom in the Baltic Sea and the crustaceans exposed under laboratory conditions to N. spumigena extract accumulated the cyclic anabaenopeptins (APs). In the crustaceans, the linear peptides, spumigins (SPUs) and aeruginosins (AERs), were additionally detected. Exposure of T. platyurus and A. franciscana to N. spumigena extract confirmed the negative effect of nodularin on the organisms. However, high numbers of dead crustaceans were also recorded in the nodularin-free fraction, which contained protease inhibitors classified to spumigins and aeruginosins. These findings indicate that cyanobacterial toxicity to aquatic organisms is a complex phenomenon and the induced effects can be attributed to diverse metabolites, not only to the known hepatotoxins.
-
phenotypic and toxicological characterization of toxic Nodularia spumigena from a freshwater lake in turkey
Harmful Algae, 2009Co-Authors: Reyhan Akcaalan, Hanna Mazurmarzec, Anna Zalewska, Meric AlbayAbstract:Abstract Cyanobacterial blooms have been occasionally observed in Iznik lake, a freshwater body (salinity = 0.5) located in the western part of Turkey. Nodularia spumigena (Mertens in Juergens) was recorded in the lake in the summer months of 2005. Maximum filament concentration of the species (1.3 × 10 5 fil L −1 ) was measured in August and constituted 60% of total cyanobacteria abundance. Trichomes were solitary, straight and had cells containing gas vesicles. Heterocysts were regularly spaced throughout the filaments. In the isolated filaments nodularin was detected by HPLC, ELISA and PPIA as well as LC–MS. HPLC analysis showed that gravimetric nodularin concentration in cultured N. spumigena cells was 578 μg of nodularin per gram dry weight (d.w.). Apart from nodularin, demethylated nodularin variant was also found in Nodularia cell extract. This is the first report of toxic N. spumigena in a European freshwater lake.
-
characterization of nodularin variants in Nodularia spumigena from the baltic sea using liquid chromatography mass spectrometry mass spectrometry
Rapid Communications in Mass Spectrometry, 2006Co-Authors: Hanna Mazurmarzec, M. Plinski, Janusz SzafranekAbstract:Nodularin is a potent hepatotoxic cyclic pentapeptide produced by planktonic cyanobacterium Nodularia spumigena. Bloom and culture samples of the cyanobacterium collected and isolated from the Gulf of Gdansk, southern Baltic Sea, were analyzed. Hybrid quadrupole-time-of-flight liquid chromatography/mass spectrometry/mass spectrometry (TOF-LC/MS/MS) with ionspray (ISP) and collision-induced dissociation (CID) were used to characterize nodularin and its analogues. The identification process was based on the comparison of recorded product ion spectra with the previously reported FAB-MS/CID (high-energy) mass spectra of the corresponding nodularin variants. Amino acid structures and sequences were derived from the fragmentation pattern of the [M+H](+) ions. Apart from unmodified nodularin with an arginine residue (NOD-R), three demethylated variants have been found. The sites of demethylation were located on aspartic acid [Asp(1)]NOD, the Adda residue [DMAdda(3)]NOD, and dehydrobutyric acid [dhb(5)]NOD. In two other nodularin variants an additional methyl group is located in the Adda [MeAdda]NOD and Glu [Glu(4)(OMe)]NOD residues. The linear NOD and the geometrical isomer of NOD-R, reported earlier in N. spumigena from New Zealand, have also been detected. Two of the total eight nodularin variants characterized in the present study, [dhb(5)]NOD and [MeAdda]NOD, have not been described earlier.
