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, immunosuppressive and enzyme inhibiting activities. In the last decades structures of pure compounds have been determined as phenols, peptides, alkaloids or terpenoids (Falch, 1996). Screening of lipophilic and hydrophilic extracts from cultured cyanobacteria or waterbloom material, isolated from German lakes and the Baltic sea for antiviral, antibiotic, immunomodulating and enzyme inhibiting activity in different in vitro systems revealed strains with interesting effects. These strains were cultivated in 45 litre photobioreactors to produce enough biomass for bioassay-guided isolation of the active substances. First results characterising active substances are reported.