Abstract

Cyanobacteria are microscopic, prokaryotic organisms capable of mass development in aquatic ecosystems. Cyanobacterial blooms, observed often in various fresh and brackish waters, are growing global problem due to the eutrophication process and climate changes. Different cyanobacterial species may produce wide range of various biologically active secondary metabolites, which may be harmful to aquatic organisms, animals and humans. Microcystins (MCs) are the most known and frequently studied cyanobacterial compounds classified to cyanotoxins. But cyanobacteria are producers of several hundred of other toxins (e.g. nodularins, cylindrospermopsins, anatoxins, saxitoxins), and potentially harmful substances (e.g. oligopeptides other than MCs). In this paper, the present knowledge about cyanobacterial blooms, toxins and other metabolites produced is shown concisely with references to the latest review reports broadly describing the issues discussed. Human health risks caused by cyanobacteria is also presented.

keywords: Cyanobacteria; Cyanotoxins; Anatoxin; Nodularin; Oligopeptides; Eutrophication