Cyanobacterial toxins: occurrence, properties and biological significance

Abstract

All of the most commonly encountered genera of cyanobacteria which form blooms and scums in fresh-brackish- and marine waters include members capable of producing potent toxins. Poisonings of vertebrate and invertebrate animals following the ingestion of cyanobacterial bloom/scum material have been widely reported for many years and recognition of the adverse effects of cyanobacterial blooms and their toxins is increasing. This review considers the occurrence of toxic cyanobacterial populations and properties of the toxins themselves, of which at least 60 are now recognised. When rightfully regarded as microbial secondary metabolites, a range of possible functions for cyanobacterial toxins is presented. Whether cyanobacterial toxins contribute to the ability of cyanobacteria to dominate many eutrophic waterbodies is unknown, although understanding of the occurrence of the toxins in aquatic environments and their actions at the molecular level and with whole organisms in laboratory studies indicates that this is possible.

A systematic study on spatial and seasonal patterns of eight taste and odor compounds with relation to various biotic and abiotic parameters in Gonghu Bay of Lake Taihu, China

“…Many cyanobacteria produce metabolites, such as biotoxins and/or taste and odor (T&O) compounds, which impact water supplies (Carmichael, 1997;Ibelings and Havens, 2008;Peter et al, 2009;Watson, 2003). Some of these compounds are water soluble and nonvolatile and have no odor, and are thus virtually undetectable by the consumer (Codd, 1995). Among which cyclic heptapeptide toxins microcystins (MCs) are one of the most common and well studied species (Chen et al, 2009a,b;Chorus and Bartram, 1999).…”

Dynamics of microcystins-LR and -RR in the phytoplanktivorous silver carp in a sub-chronic toxicity experiment

“…Cyanotoxins produced by freshwater cyanobacteria are very common worldwide, and have been reported to cause poisonings and deaths of wild and domestic animals (Codd, 1995;Dawson, 1998;Carmichchael, 2001) and even significant hazards to human health (Yu, 1995;Pouria et al, 1998). One of the most studied groups of cyanotoxins is the cyclic heptapeptide hepatotoxins called microcystins (MC), of which over 60 structural variants are currently known (Sivonen and Jones, 1999).…”

Removal of cyanobacterial microcystin-LR by ferrate oxidation–coagulation

“…The increasing eutrophication of fresh waters many of which include drinking water reservoirs by human activity has increased the occurrence and intensity of cyanobacterial blooms (Sivonen et al, 1990) and approximately 50% of them are known to be toxic (Codd, 1995). The most commonly occurring toxins produced by cyanobacteria are microcystins.…”