CHARACTERIZATION AND ANTIMICROBIAL SPECTRUM OF A POTENT STREPTOMYCES SP. GOS2 ISOLATED FROM WESTERN GHATS OF KARNATAKA, INDIA
Objective: Western Ghats of Karnataka, India-a biodiversity hotspot is a rich source of microorganisms with undiscovered metabolic capabilities. The upsurge of antibiotic-resistant pathogens has created a greater demand for novel antibiotics. In context to the above a potent soil Streptomyces sp. GOS2 isolated from Agumbe regions of Western Ghats, and its metabolite was assessed and characterized for its antimicrobial spectrum.
Methods: The isolation was carried out by soil serial dilution plating on Starch Casein Nitrate agar media (SCN). The obtained isolate was characterized by morphological and biochemical tests. The antimicrobial activity was assessed by well in agar methods against 28 test organisms. The partial characterization of the bioactive metabolite was carried out by thin layer chromatography (TLC) and UVâ€“Visible spectroscopy studies.
Results: The isolated GOS2 was observed as a raised powdery colony with grey colored aerial mycelium and media impregnated substrate mycelium. The spore chain was rectus with smooth spore surface. The isolate was gram positive, non-acid fast, positive for catalase, hydrogen sulphide production and starch hydrolysis, negative for casein and gelatin hydrolysis. The carbohydrate fermentation studies showed acid production in dextrose and alkali production in sucrose, lactose, maltose and starch. A prominent antibacterial activity was observed with a zone of inhibition measuring 21-27 mm. The TLC showed a purple spot and UV spectroscopy revealed Î» max at 233.2 and 235 nm indicating macrolide group of antibiotics.
Conclusion: Western Ghats actinomycetes are a potent source of novel antibiotic molecules.
2. Alanis JA. Resistance to antibiotics: are we in the post-antibiotic era? Arch Med Res 2005;36:697-705.
3. Tanaka YT, Omura S. Aero active compounds of microbial origin. Ann Rev Microbiol 1993;47:57-87.
4. Chun JS, Youn HD, Yim YI, Lee HK, Kim MY, Hah YC, Kang SO. Streptomyces seoulensis sp. nov. Int J Syst Evol Microbiol 1997;56:471-5.
5. Kim BS, Hwang BK. Biofungicides. In: Arora DK. editors. Fungal Biotechnology in Agricultural, Food and Environmental Applications. New York: Marcel Dekker; 2003. p. 123-33.
6. Prajapati RC. Biodiversity of Karnataka-At a glance. Karnataka Biodiversity Board (Forest, Ecology and Environment Department) Government of Karnataka; 2010.
7. Shirling EB, Gottlieb D. Methods for characterization of Streptomyces species. Int J Syst Bacteriol 1966;16:313-40.
8. Williams ST, Sharpe ME, Holt JG. Bergeyâ€™s manual of systematic bacteriology. In: Murray RGE, Brenner DJ, Holt JG, Krieg NR, Moulder JW, Pfenning N, et al. editors. 1st ed. Baltimore, Williams and Wilkins; 1989.
9. Holt JG, Krieg RN, Sneath PHA, Staley JT, Williams ST. Bergeyâ€™s manual of determinative bacteriology. 9th ed. Lippincott Williams and Wilkins, Baltimore: USA; 2000.
10. Augustine SK, Bhavsar SP, Baserisalehi M, Kapadnis BP. Isolation, characterization and optimization of antifungal activity of actinomycetes of soil origin. Indian J Exp Biol 2004;42:928-32.
11. Augustine SK, Bhavsar SP, Kapadnis BP. A nonpolyene antifungal antibiotic from Streptomyces albidoflavus PU23. J Biosci 2005;30:201-11.
12. Waksman SA, Henrici AT. The nomenclature and classification of the actinomycetes. J Bacteriol 1943;46:337-41.
13. Gaynor M, Mankin AS. Macrolide antibiotics: binding site, mechanism of action, resistance. Curr Top Med Chem 2003;3:949-61.
14. Manivasagan P, Venkatesan J, Sivakumar K, Kim SK. Pharmaceutically active secondary metabolites from actinobacteria. Microbiol Res 2014;169:262â€“78.