The regulation of microcystin biosynthesis pathways and genetic mechanisms [Mikrosistin biyosentez yolaklari{dotless}ni{dotless}n düzenlenmesi ve genetik mekanizmalar]

Abstract

The cyanobacteria (blue-green algae), as they are commonly named, comprise a diverse group of oxygenic photosynthetic bacteria that inhabit a wide range of aquatic and terrestrial environments, and display incredible morphological diversity. Cyanobacteria produce bioactive secondary metabolites, including alkaloids, polyketides and non-ribosomal peptides, some of which are potent toxins. The common occurrence of toxic cyanobacteria causes problems for health of animals and human. Cyanobacterial toxins or cyanotoxins are responsible diseases such as liver cancer, dermal contact irritations and gastroenteritis in humans. The cyanotoxins divide four major classes: the neurotoxins, hepatotoxins, cytotoxins, and dermatoxins. However, this toxins are quite variety. The biosynthesis pathways of the four major cyanotoxins: microcystin, saxitoxin, nodularin and cylindrospermopsin, have been interpreted as biochemical and genetical in the past decade. Microcystins have been implicated in several cases of animal and human intoxications. This review summarizes biosynthesis pathways of microcystin, chemistry, genetic and toxicology.