Int.J.Curr.Microbiol.App.Sci (2015) Special Issue-2: 343-356 343 Original Research Article Biosurfactant Mediated Plant Growth Promotion in Soils Amended with Polyaromatic Hydrocarbons Smita Bhuyan-Pawar 1,2 *, Reshma P.Yeole 1 , Vynkatesh M. Sanam 1 , Shradha P. Bashetti 1 and Shilpa S. Mujumdar 1 1 Department of Microbiology, Modern College of Arts, Science and Commerce, Shivajinagar, Pune 411 005, India 2 Microbial Drugs, Helmholtz centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany *Corresponding author ABSTRACT Introduction Polyaromatic hydrocarbons (PAH) also known as polynuclear aromatic hydrocarbons are group of most widespread organic pollutants found in soil, sediment and oily substances. These compounds are a major cause of concern recently because some of them are potentially carcinogenic, mutagenic and teratogenic and hence a International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Special Issue-2 (May-2015) pp. 343-356 http://www.ijcmas.com The present study was carried out with the perspective of obtaining a potent biosurfactant employing molasses as substrate and evaluation of its potential for Plant growth in soils contaminated with polyaromatic hydrocarbons. Streptomyces sp. V2was grown in optimized medium containing molasses as the carbon source and purified by acid precipitation followed by solvent extraction. The purified biosurfactant was used to determine its chemical composition, surface active properties, antimicrobial potential and potential to alleviate stress of phenanthrene and anthracene on plantlets. Our results indicate that Streptomyces sp. V2 produced a potent biosurfactant. The biosurfactant was amorphous brown, water soluble and proteoglycan in nature. The yield of the biosurfactant was 56.7 mg/L and reduced the surface tension of water by 11.020 ± 0.526 mN/m. It reduced the interfacial tension between kerosene water interface by 4.802 ± 0.186 mN/m and had a CMC of 72 mg/L. The biosurfactant exhibited weak antibacterial activity and was stable over a wide range of pH and temperature. Unpaired “t” test (p<0.05) to determine significant difference due to different treatments revealed that addition of biosurfactant to phenanthrene and anthracene amended soils, significantly increased the vitality and growth of Trigonellafoenum-graecum and Triticum spp. Thus biosurfactant from Streptomyces sp. V2 was promising and could find potential in bioremediating PAH contaminated soils. The biosurfactant was efficiently produced using molasses thereby lowering environmental stress. Keywords Biosurfactant, Streptomyces, Polyaromatic hydrocarbons, Plant growth promotion