ANTIMICROBIAL POTENTIALS OF TWO FRESHWATER HETEROCYSTOUS CYANOBACTERIA WESTIELLOPSIS PROLIFICA AND NOSTOCHOPSIS LOBATUS COLLECTED FROM SIMILIPAL BIOSPHERE RESERVE, ODISHA, INDIA

Abstract

The Similipal Biosphere Reserve, an unique ecosystem in the eastern part of India, occupy the northern boundary of Odisha state, lies between 21°28´ to 22°08´ North latitude and 86°04´ to 86°37´ East longitude, covering a vast area of 5578 sq. km in the district of Mayurbhanj. Westiellopsis prolifica and Nostochopsis lobatus, are a group of heterocystous, true branched, filamentous cyanobacteria belonging to the order Stigonematales, rarely found in the aquatic bodies of this region in the state of Odisha. In the present investigation, an attempt has been made to evaluate the antimicrobial potentials of Westiellopsis prolifica and Nostochopsis lobatus collected from flowing streams of Similipal Biosphere Reserve. The organisms were cultured in nitrogen free BG-11 medium and raised to axenic state. Crude metabolites were extracted from cultured test organisms in late log phase using organic solvents of different polarity viz. methanol and chloroform. The metabolites were tested against some clinically significant microorganisms including bacteria and fungi using agar cup diffusion method and the results of antimicrobial activity of cyanobacteria are summarized. The findings revealed that pattern of inhibition varied with respect to the cyanobacterial strains used, nature of solvent extracts and the pathogenic microorganisms tested. Westiellopsis prolifica was found to be more potent that inhibit all the pathogenic bacteria and fungi both in methanol and chloroform extract. This study illustrates that heterocystous cyanobacteria from freshwater bodies could be a potent source of antimicrobial agents and further characterization of active metabolites and evaluation of their pharmacological potentials are also needed.