Lethal and behavioral effects of semi-purified microcystins, Micropeptin and apolar compounds from cyanobacteria on freshwater microcrustacean Thamnocephalus platyurus.

The mass proliferation of cyanobacteria, episodes known as blooms, is a concern worldwide. One of the most critical aspects during these blooms is the production of toxic secondary metabolites that are not limited to the four cyanotoxins recognized by the World Health Organization. These metabolites comprise a wide range of structurally diverse compounds that possess bioactive functions.

Lethal and sublethal effects towards zebrafish larvae of microcystins and other cyanopeptides produced by cyanobacteria.

Cyanobacterial blooms affect aquatic ecosystems across the globe and one major concern relates to their toxins such as microcystins (MC). Yet, the ecotoxicological risks, particularly non-lethal effects, associated with other co-produced secondary metabolites remain mostly unknown. Here, we assessed survival, morphological alterations, swimming behaviour and cardiovascular functions of zebrafish (Danio rerio) upon exposure to cyanobacterial extracts of two Brazilian Microcystis strains.

inactivation and microcystin-LR degradation by the photo-Fenton process at the initial near-neutral pH.

Of all cyanobacteria, Microcystis aeruginosa is the most commonly found species in bloom episodes all over the world. This species is known to produce cyanopeptides with hepatotoxic effects, namely microcystins (MCs). In this regard, Advanced Oxidation Processes (AOPs) have been widely studied for cyanotoxin degradation, but very few studies focused on cyanobacteria inactivation combined with toxin removal.

Does the photo-Fenton reaction work for microalgae control? A case study with Desmodesmus subspicatus.

Increased concentrations of nutrients in water bodies caused by effluent discharge, fertilizers and other inputs can lead to artificial eutrophication, increasing the primary productivity, bringing well-known and serious consequences to the environment (such as excessive macrophyte and microalgae growth). Most strategies for phytoplankton control in aquatic ecosystems result in metal accumulation or toxic by-product formation after chlorination. Concerning this matter, the photo-Fenton process (usually applied in wastewater treatment and degradation of a variety of contaminants) has been studied for water and effluent disinfection.