Enhancement of glycolipid production by Stenotrophomonas acidaminiphila TW3 cultivated in low cost substrate

Abstract

This study aimed to investigate potential biosurfactant production of Stenotrophomonas acidaminiphila TW3 isolated from sediments contaminated with palm oil soapstocks using low cost substrates. The combination of central composite rotatable design (CCRD) and response surface methodology (RSM) was used to optimize biosurfactant production. The highest biosurfactant production (2.31 g/L) was obtained under the optimal conditions of 49.96 g/L used palm oil as a carbon source, 3.00 g/L NaNO 3 as a nitrogen source and medium pH 6.0. RSM increased the yield of biosurfactant up to 2.1 folds however, the productivity is still low further improvement is needed. The biosurfactant obtained from the S. acidaminiphila TW3 was able to lower the surface tension of medium from 72 to 32 mN/m. The biosurfactant was purified by liquid column chromatography and identified as glycolipid using thin layer chromatography, Fourier transform infrared spectroscopy, Mass spectrometer and Nuclear Magnetic Resonance. The biosurfactant could reduce surface tension of pure water to 32 mN/m with a critical micelle concentration of 0.2 g/L. It is an effective biosurfactant over a wide range of temperatures, pH and salt concentrations. Moreover, the biosurfactant showed ability to enhance PAHs solubility and removed used lubricating oil contaminated in sand. • The production of biosurfactant by strain TW3 was optimized by RSM methodology. • The biosurfactant produced by strain TW3 was identified as glycolipid. • Biosurfactant activity was stable under extreme conditions. • This glycolipid increased PAHs solubility and removed ULO.