Microcystins appear to be considered one of the most dangerous cyanobacterial toxins in world. The accumulation and change microcystins MC-LR MC-RR “cyanobacteria–cladocera–fish” food chain were studied. Microcystis aeruginosa was fed Moina macrocopa at three densities, 5.0 × 103, 105, 106 cells/mL, then passed Cyprinus flammans. total amount MCs cyanobacteria cell extract increased with increa...

The cyanobacterium Microcystis occurs as colonies of different sizes with varying abundance of toxic genotypes versus non-toxic genotypes under natural conditions. To investigate the effects of toxic Microcystis genotypes on natural colony formation, samples collected from the mainstream of Haihe River from July to October 2015 were sieved into four colony classes with sizes of <8 μm, 8-20 μm, ...

Bacterial degradation of toxic microcystins produced by cyanobacteria is a common phenomenon. However, our understanding of the mechanisms of these processes is rudimentary. In this paper several novel discoveries regarding the action of the enzymes of the mlr cluster responsible for microcystin biodegradation are presented using recombinant proteins. In particular, the predicted active sites o...

We investigated the intestinal uptake and adverse effects of microcystins ingested with Microcystis on Daphnia galeata. The gut structure, blood microcystin concentration, appearance, and movements of Daphnia fed Microcystis PCC 7806 or a microcystin-deficient PCC 7806 mutant were monitored over time. Microcystins were rapidly taken up from the digestive cavity into the blood. This process appa...

Cyanobacterial blooms in freshwaters represent a major ecological and human health problem worldwide. This paper briefly summarizes information on major cyanobacterial toxins (hepatotoxins, neurotoxins etc.) with special attention to microcystins-cyclic heptapeptides with high acute and chronic toxicities. Besides discussion of human health risks, microcystin ecotoxicology and consequent ecolog...

Microcystis is a well-known cyanobacterial genus frequently producing hepatotoxins named microcystins. Toxin production is encoded by microcystin genes (mcy). This study aims (i) to relate the mcy occurrence in individual colonies to the presence of microcystin, (ii) to assess whether morphological characteristics (morphospecies) are related to the occurrence of mcy genes, and (iii) to test whe...

This case study compared microcystins in tap water from 18 public systems (PWSs) and 46 households with private intakes or nearshore wells (called self-supplied [SSWS]) Clear Lake, California during a major cyanobacterial bloom 2021. Microcystin concentrations were below the US EPA health advisory (HA; 0.3 μg/L) for PWS Lake SSWS drawing wells. However, (intake SSWS), 24 of 79 microcystin sampl...

Microcystins (MCs) are among the most prevalent and potent of the cyanobacterial toxins (cyanotoxins) and their potential occurrence in waters required for drinking has prompted investigations into remedial water treatments for their removal. We have investigated the suitability of local pumice, as a possible low-cost material for environmental application for the removal of cyanotoxins. Adsorp...