Bioactive compounds from Pseudanabaena species (Cyanobacteria)

Bioactive products of the multicellular filamentous benthic cyanobacterium, Pseudanabaena species, isolated from wastewater stabilization ponds at Mar rakech, were tested against some pathogenic micro-organisms. Extracellular and intracellular products released by this blue-green alga in the stationa ry growth phase, reduced the survival of Escherichia coli, Salmonella sp., Staphylococcus aureus and Candida albicans, and stimulated the growth of no n-O1 V cholerae, whereas no significant effect was noted on the growth of C andida tropicalis. Intracellular substances (methanolic extract) had a stro nger inhibitory effect on these micro-organisms than that produced by extra cellular substances. These antibacterial and antifungal substances may have a pharmacological value. They may have an important ecological effect on t he composition of the bacterial community in Marrakech stabilization ponds when blooms of Pseudanabaena species occurred in this sewage treatment ecos ystem during hot periods.