Cyanobacterial natural products as antimicrobial agents.

Cyanobacteria (Blue-green algae) are a primitive, diverse and ubiquitous group of photosynthetic prokaryotes, exhibiting resemblance with Gram-negative bacteria in cellular organization and green plants in oxygenic photosynthesis (Stanier and Cohen-Bazire, 1977). With long evolutionary history, they are among the oldest life forms existing on earth. They colonize, grow and survive in almost all kinds of terrestrial and aquatic (freshwater and marine) ecosystems which can be attributed to their tremendous adaptability to varying environmental conditions as well as effective protective and tolerance mechanisms against various abiotic stresses (Tandeau de Marsac and Houmard, 1993; Potts, 1999; EhlingSchulz and Scherer, 1999). With remarkable diversity in their structure, which may be unicellular, colonial or filamentous (branched or unbranched); they include 150 genera with more than 2000 species. The presence or production of a wide array of photosynthetic ISSN: 2319-7706 Volume 4 Number 1 (2015) pp. 310-317 http://www.ijcmas.com