Optimization of production of biosurfactant from microorganism and its application in bioremediation

Abstract

Surfactants are surface active molecules capable of reducing surface tension and interfacial tension at interface between liquids, solids. They have been used extensively in environmental remediation, petroleum industries, detergent industries etc. The accumulation of synthetic surfactant in the environment leads to harmful effect on microbes, plants and human being. Owing to the increasing awareness on the protection of ecosystem, the focus on biosurfactant has tremendously increased, as it is a possible alternative for surfactants. However the high production cost and low product yield is affecting the commercialization of biosurfactants. In the present research work, biosurfactant producing bacteria was isolated from hydrocarbon contaminated soil. 18 isolates showed biosurfactant producing ability out of 53 different colonies, which were obtained from 7 different hydrocarbon contaminated soil samples. Based on the results of oil drop collapse method and oil dispersion test, 7 isolates were identified asrelatively better biosurfactant producing microorganisms. Among seven isolates, AMB AS7 was chosen for further studies based on high surface tension reduction capacity (57.69 ± 1.1%) and Emulsification index 49.4 ± 1.2%. The biochemical characterization and 16s rRNA sequencing results revealed that the isolate AMB AS7 has 99% similarity to Pseudomonas aeruginosa and is named as Pseudomonas aeruginosa AMB AS7 (NCBI accession number C822322). newline newline newline newline