Mediterranean Cyanobacterial Biodiversity and Bioactivity

Marine cyanobacteria are photosynthetic prokaryotes of significant ecological interest, living free or in association with invertebrates. They are also considered as excellent sources of antineoplastic, antibacterial, antiviral and antifungal compounds. In Mediterranean sea, microbiological procedures evidenced the contribution, not only of the unicellular Synechococcus spp., but also of filamentous forms (species belonging to the genera Stanieria, Geitlerinema, Leiblenia, Leptolyngbya, Oscillatoria, Pseudanabaena and Spirulina), to the phytoplankton diversity. As concerning species living in association with sponges, bioassays with human erythrocytes, brine shrimp nauplii, and sea urchin gametes and embryos evidenced the bioactive properties of eight strains isolated from Petrosia ficiformis. A combined phenotypic and genetic approach (polyphasic approach) was applied to characterize one of these strains, Halomicronema metazoicum ITAC101 sp. nov., very interesting from both an ecological and toxicological point of view. All these studies evinced the necessity to collecting strains from different substrata and localities to discover new cyanobacterial species and novel bioactive compounds with potential applications in pharmaceutics.