Microcystins and Nodularins

Catherine, Arnaud; Bernard, Cécile; Spoof, Lisa; Bruno, Marco

doi:10.1002/9781119068761.ch11

Cited by 57 publications

(61 citation statements)

References 158 publications

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“…For early detection of potentially toxigenic cyanobacteria and cyanotoxins, rapid, reliable, and economically effective molecular approaches based on a PCR (polymerase chain reaction) targeting genes involved in the biosynthesis of cyanotoxins have been developed in the past 15 years [21]. Cyanotoxins which include the group of potent hepatotoxins-MCs and NODs-are produced through non-ribosomal peptide synthesis and exhibit biosynthetic routes that shared many similarities [22]. For MCs in particular, the large enzyme complex involved in their production is encoded by a cluster of 10 genes, called microcystin synthetase genes (mcyA-J) [22], from which the NOD gene cluster (nda cluster) arose [23].…”

Section: Introductionmentioning

confidence: 99%

“…Cyanotoxins which include the group of potent hepatotoxins-MCs and NODs-are produced through non-ribosomal peptide synthesis and exhibit biosynthetic routes that shared many similarities [22]. For MCs in particular, the large enzyme complex involved in their production is encoded by a cluster of 10 genes, called microcystin synthetase genes (mcyA-J) [22], from which the NOD gene cluster (nda cluster) arose [23]. The identification of MC-producing species and strains through amplifications of six of these genes (mcy A-E) became most commonly applied [21,24].…”

Section: Introductionmentioning

confidence: 99%

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Morphological and Molecular Identification of Microcystin-Producing Cyanobacteria in Nine Shallow Bulgarian Water Bodies

Radkova

Stefanova

Uzunov

et al. 2020

Toxins

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The paper presents results from the first application of polyphasic approach in studies of field samples from Bulgaria. This approach, which combined the conventional light microscopy (LM) and molecular-genetic methods (based on PCR amplified fragments of microcystin synthetase gene mcyE), revealed that almost all microcystin-producers in the studied eutrophic waterbodies belong to the genus Microcystis. During the molecular identification of toxin-producing strains by use of HEPF × HEPR pair of primers, we obtained 57 sequences, 56 of which formed 28 strains of Microcystis, spread in six clusters of the phylogenetic tree. By LM, seven Microcystis morphospecies were identified (M. aeruginosa, M. botrys, M. flos-aquae, M. natans, M. novacekii, M. smithii, and M. wesenbergii). They showed significant morphological variability and contributed from <1% to 98% to the total biomass. All data support the earlier opinions that taxonomic revision of Microcystis is needed, proved the presence of toxigenic strains in M. aeruginosa and M. wesenbergii, and suppose their existence in M. natans. Our results demonstrated also that genetic sequencing, and the use of HEPF × HEPR pair in particular, can efficiently serve in water quality monitoring for identifying the potential risk from microcystins, even in cases of low amounts of Microcystis in the water.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Morphological and Molecular Identification of Microcystin-Producing Cyanobacteria in Nine Shallow Bulgarian Water Bodies

Radkova

Stefanova

Uzunov

et al. 2020

Toxins

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“…Purified 1 (250 µg) was dissolved in 30 µL of CD 3 OH for NMR spectroscopy. NMR spectra were acquired on a Bruker Avance III 600 MHz spectrometer (Bruker Biospin Ltd., Billerica, MA, USA) operating at a 1 H frequency of 600.28 MHz and 13 C frequency of 150.94 MHz using TOPSPIN 2.1 acquisition software with a 1.7 mm TXI gradient probe at 277 K. Standard Bruker pulse sequences were used for structure elucidation: one dimensional 1 H spectrum with composite pulse pre-saturation of water, double quantum filtered 1 H-1 H COSY, 1 H-1 H DIPSI-2 (mixing time 120 ms), 1 H-13 C HSQC, 1 H-13 C HMBC (60 and 90 ms delay for long range coupling evolution), 1 The initial survey of cultures for the presence of MCs was performed by LC-UV-MS using an Agilent (Mississauga, ON, Canada) 1200 LC coupled with a SCIEX (Concord, ON, Canada) API 4000 Q-Trap mass spectrometer with UV monitoring at 238 nm and positive electrospray ionization MS, with full scans, m/z 135 precursor scans, product ion scans, and selected reaction monitoring. The LC column (50 × 2.1 mm; Agilent) was packed with 1.8 µm Zorbax SB-C18 and maintained at 40 • C. The flow rate was 0.3 mL/min, with a gradient of 10%-80% B over 30 min.…”

Section: General Experimental Proceduresmentioning

confidence: 99%

“…Adda 5 and Glu 6 appear to be primarily responsible for the characteristic biological activity of MCs [2,3]. Protein phosphatase inhibition is directly related to the toxins' mechanism of action and animal studies have demonstrated that MCs are potent tumor promoters [1]. To date, the number of identified MCs continues to increase and more than 250 analogues have been characterized [4].…”

Section: Introductionmentioning

confidence: 99%

Isolation and Characterization of [D-Leu1]microcystin-LY from Microcystis aeruginosa CPCC-464

LeBlanc

Merkley

Thomas

et al. 2020

Toxins

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[D-Leu1]MC-LY (1) ([M + H]+ m/z 1044.5673, Δ 2.0 ppm), a new microcystin, was isolated from Microcystis aeruginosa strain CPCC-464. The compound was characterized by 1H and 13C NMR spectroscopy, liquid chromatography–high resolution tandem mass spectrometry (LC–HRMS/MS) and UV spectroscopy. A calibration reference material was produced after quantitation by 1H NMR spectroscopy and LC with chemiluminescence nitrogen detection. The potency of 1 in a protein phosphatase 2A inhibition assay was essentially the same as for MC-LR (2). Related microcystins, [D-Leu1]MC-LR (3) ([M + H]+ m/z 1037.6041, Δ 1.0 ppm), [D-Leu1]MC-M(O)R (6) ([M + H]+ m/z 1071.5565, Δ 2.0 ppm) and [D-Leu1]MC-MR (7) ([M + H]+ m/z 1055.5617, Δ 2.2 ppm), were also identified in culture extracts, along with traces of [D-Leu1]MC-M(O2)R (8) ([M + H]+ m/z 1087.5510, Δ 1.6 ppm), by a combination of chemical derivatization and LC–HRMS/MS experiments. The relative abundances of 1, 3, 6, 7 and 8 in a freshly extracted culture in the positive ionization mode LC–HRMS were ca. 84, 100, 3.0, 11 and 0.05, respectively. These and other results indicate that [D-Leu1]-containing MCs may be more common in cyanobacterial blooms than is generally appreciated but are easily overlooked with standard targeted LC–MS/MS screening methods.

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“…Microcystins are cyclic heptapeptides that have been firstly described from M. aeruginosa. Above 250 different variants have been described so far (Catherine et al, 2017), 138 being references in our database for cyanobacterial metabolite (supplementary table 1). They are characterized by the presence of a non-proteinacous amino acid in position 5 (Adda), two amino acid derived from Asp and Glu in position 3 and 6, respectively, and 2 very variable positions (2 and 4), that serve as reference to the name of the variant.…”

Section: Known Cyanobacteria Secondary Metabolite Clusters Microcystinsmentioning

confidence: 99%

Global metabolomic characterizations of Microcystis spp. highlights clonal diversity in natural bloom-forming populations and expands metabolite structural diversity

Marie

Manach

Duval

et al. 2018

Preprint

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Cyanobacteria are photosynthetic prokaryotes that are able to synthetize a wild rang of secondary metabolites exhibiting noticeable bioactivity, comprising toxicity. Microcystis represents one of the most common cyanobacteria taxa constituting the intensive blooms that arise nowadays in freshwater ecosystems worldwide. They produce numerous cyanotoxins (toxic metabolites), which are potentially harmful to Human health and aquatic organisms. In order to better understand the variations in cyanotoxins production between clones of the same blooms, we investigate the diversity of several Microcystis strains isolated from different freshwater bloom-forming populations from various geographical area. Twenty-four clonal strains were compared by genotyping with 16S-ITS fragment sequencing and metabolites chemotyping using LC ESI-qTOF mass spectrometry. While, genotyping can only discriminate between the different species, the global metabolomes reveal clear discriminant molecular profiles between strains, which can be clustered primarily according to their global metabolite content, then to their genotype, and finally to their sampling localities. A global molecular network generated from MS/MS fractionation patterns of the various metabolite detected in all strains performed with GNPS tool highlight the production of a wide set of chemically diverse metabolites, comprising only few microcystins, but many aeruginosins, cyanopeptolins and microginins, along with a large set of unknown molecules that still remain to be investigated and characterized at their structure as well as at their potential bioactivity or toxicity levels. Figure 1: Microcystis spp. General view of a representative intense Microcystis sp. bloom in a recreational pound (Champs-sur-Marne) (A). Macrograph of Microcystis colonies at surface water (B). Example of 15-mL vessels containing the monoclonal strains of Microcystis spp. maintained in the Paris' Museum Collection (PMC) of cyanobacteria (MNHN, Paris) (C). Example of micrograph of the isolated monoclonal culture of the Microcystis aeruginosa, where scale bare represents 10 µm (D). Representative picture of Microcystis aeruginosa cell from PMC 156.02 strain (here in division) under transmission electron microscope, where scale bare represents 0.5 µm (E). General structures of various cyanobacterial metabolites belonging to the microcystin, anabaenopeptin, microginin microviridin, aeruginosin and oscillatorin families (F).Microcystis wesenbergii PMC 672.10 84 Microcystis wesenbergii PMC 671.10 Microcystis wesenbergii PMC 673.10 Microcystis wesenbergii PMC 674.10 Microcystis wesenbergii NIES111 (3551457) (AB015388) Microcystis wesenbergii TAC52 (3551459) (AB015390) Microcystis sp. PMC 807.12 Microcystis viridis PMC 566.08 88 Microcystis wesenbergii NIES44 (3551456) (AB015387) Microcystis viridis TAC17 (3551467) (AB015398) Microcystis viridis W191 (295983850) (HM017091) Microcystis viridis W18 (295983846) (HM017087) Microcystis aeruginosa PMC 265.05 Microcystis sp. PMC 816.12 Microcystis aeruginosa PMC...

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Microcystins and Nodularins

Cited by 57 publications

References 158 publications

Morphological and Molecular Identification of Microcystin-Producing Cyanobacteria in Nine Shallow Bulgarian Water Bodies

Morphological and Molecular Identification of Microcystin-Producing Cyanobacteria in Nine Shallow Bulgarian Water Bodies

Isolation and Characterization of [D-Leu1]microcystin-LY from Microcystis aeruginosa CPCC-464

Global metabolomic characterizations of Microcystis spp. highlights clonal diversity in natural bloom-forming populations and expands metabolite structural diversity

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