BIOSURFACTANTS PRODUCED BY A NEWLY ISOLATED PSEUDOMONAS FLUORESCENS HW-6 DURING GROWTH ON HEXADECANE

ABSTRACT. The newly isolated from industrial wastewater samples Pseudomonas fluorescens strain HW-6 produced biosurfactants during growth on hexadecane as sole source of carbon and energy. Hemolysis of erythrocytes, growth inhibition of Bacillus subtilis and thin-layer chromatography revealed that the secreted biosurfactants are rhamnolipids. They decreased the surface tension of water from 72 mN m-1 to 32 mN m-1 and achieved a critical micelle concentration value of 20 mg l-1. They efficiently emulsified aromatic hydrocarbons, kerosene, n-paraffin and mineral oil. The results showed that the newly isolated Pseudomonas fluorescens HW-6 and its produced glycolipids with effective surface and emulsifying properties represent a promising potential for application in bioremediation of polluted with hydrocarbons wastewaters. KEY WORDS. Biosurfactants, Rhamnolipids, Hydrophobicity, Pseudomonas fluorescen