Biological Screening of Terrestrial and Freshwater Cyanobacteria for Antimicrobial Activity, Brine Shrimp Lethality, and Cytotoxicity

A total of 44 lipophilic and hydrophilic extracts obtained from 22 samples of cultured terrestrial and freshwater cyanobacteria were investigated for their biological activities.Of these, 54.5% of all extracts showed activity against Grampositive bacteria while 9.1% possessed antifungal activity against Candida albicans.No extract was active against Gram-negative bacteria.Two extracts exhibited significant activity against brine shrimp (Artemia salina).Cytotoxic activity against KB cells was demonstrated for 38.6% of the extracts.Of the 22 cyanobacteria investigated, 19 were active in at least one of the assays used.These results prove that terrestrial and freshwater cyanobacteria are still a promising source of new bioactive natural products.