Biochemical and pharmacological investigations of selected cyanobacteria

Cyanobacteria are a very old group of prokaryotic organisms that produce a variety of secondary metabolites with antibiotic, algicide, cytotoxic, immu nosuppressive and enzyme inhibiting activities. In the last decades structu res of pure compounds have been determined as phenols, peptides, alkaloids or terpenoids (Falch, 1996). Screening of lipophilic and hydrophilic extrac ts from cultured cyanobacteria or waterbloom material, isolated from German lakes and the Baltic sea for antiviral, antibiotic, immunomodulating and e nzyme inhibiting activity in different in vitro systems revealed strains wi th interesting effects. These strains were cultivated in 45 litre photobior eactors to produce enough biomass for bioassay-guided isolation of the acti ve substances. First results characterising active substances are reported.