Chemical and Biological Studies of Cyanobacteria

Abstract

Cyanobacteria are photosynthetic prokaryotic microalgae which are found in marine, brackish and
freshwater environments and in soils. Cyanotoxins including hepatotoxins and neurotoxins are produced by
cyanobacteria commonly found in surface water. The most widely studied hepatotoxins are microcystins and
nodularin which were first isolated from Microcystis aeruginosa and Nodularia spumigena, respectively. M.
aeruginosa and N. spumigena were cultured and extracted with methanol. The qualitative and quantitative analysis of
microcystins and nodularin in cultured cyanobacterial fractions were performed by HPLC. Fluorescein diacetate
(FDA) antimicrobial and brine shrimp lethality assay were carried out to determine minimum inhibitory
concentration (MIC) and general toxicity of these fractions, respectively. An unusual metabolite named as
nodularinol was isolated for the first time from N. spumigena.