Cyanobacteria (blue-green algae) produce toxins that may present a hazard for drinking water safety. These toxins (microcystins, nodularins, saxitoxins, anatoxin-a, anatoxin-a(s), cylindrospermopsin) are structurally diverse and their effects range from liver damage, including liver cancer, to neurotoxicity. The occurrence of cyanobacteria and their toxins in water bodies used for the productio...

The aim of our study was to assess whether cyanotoxins (microcystins) can affect the composition of the zooplankton community, leading to domination of microzooplankton forms (protozoans and rotifers). Temporal variations in concentrations of microcystins and zooplankton biomass were analyzed in three eutrophic reservoirs in the semi-arid northeast region of Brazil. The concentration of microcy...

The occurrence of diverse oligopeptides in cyanobacteria, including the cyanotoxins microcystins, has been recently used to classify individual clones into sub-specific oligopeptide chemotypes, whose composition and dynamics modulate microcystin concentrations in cyanobacterial blooms. Cyanobacterial chemotyping allows the study of the ecology of chemotypical subpopulations, which have been sho...

The production of toxin from bloom, scum or mat forming cyanobacteria in fresh, brackish and marine waters is becoming a global issue. The toxins produced comprise mainly hepatotoxins and neurotoxins. Of these toxins microcystin is a cyclic heptapeptide produced by Microcystis, Planktothrix, Anabaena, Nostoc, Hapalosiphon and Anabaenopsis. Microcystins (MCs) comprise more than 80 variants and a...

Cyanobacteria are well known for their production of non-ribosomal cyclic peptide toxins, including microcystin, in temperate and tropical regions, however, the production of these compounds in extremely cold environments is still largely unexplored. Therefore, we investigated the production of protein phosphatase inhibiting microcystins by Antarctic cyanobacteria. We have identified microcysti...

Microcystins and nodularin are potent hepatotoxins produced by fresh and seawater cyanobacteria. The persistence of three hepatotoxins – microcystin-LR, microcystin-RR and nodularin – was investigated in sterile BG-11 medium of different salinity and in water collected from the Gulf of Gdańsk. After 21 days of incubation at 17± 1◦C and constant illumination of about 40 μmol photon m−2 s−1 the c...

The effects of microcystins on Daphnia galeata, a typical filter-feeding grazer in eutrophic lakes, were investigated. To do this, the microcystin-producing wild-type strain Microcystis aeruginosa PCC7806 was compared with a mcy- PCC7806 mutant, which could not synthesize any variant of microcystin due to mutation of a microcystin synthetase gene. The wild-type strain was found to be poisonous ...

Microcystins, which are cyclic heptapeptides produced by some cyanobacterial species from algal blooms, strongly inhibit serine/threonine protein phosphatase and are known as hepatotoxins. Microcystins have many structural variations, yet insufficient information is available on the differences in the cytotoxic potentials among the structural variants. In this study, the cytotoxicities of 16 mi...

Microcystins are cyclic heptapeptides synthesized by various genera of cyanobacteria where Microcystis is major toxin producing genera. Several variants (>100) of microcystin have been reported. Microcystins are highly toxic and hepatotoxic in nature. Microcystin intoxication in vertebrates mainly affects the intestine and liver although liver is the maximum affected organ. Microcystin toxicity...

The frequency and intensity of cyanobacterial blooms continue to increase in freshwater systems across the globe. Cyanobacteria can release toxins several bioactive secondary metabolites analytical methods are needed effectively assess their concentrations surface waters. Since booms evolve rapidly parts a lake, high resolution spatial temporal sampling increases complexity monitoring efforts. ...