Fermentative Production of Sophorolipid and Purification by Adsorption Chromatography

Abstract A sophorolipid (glycolipid biosurfactant from Starmerella bombicola) has valuable properties in addition to surface active attributes. This sophorolipid was produced as a secondary metabolite by submerged fermentation using hydrophobic (sunflower oil) and hydrophilic (glucose) substrate. The present work investigates the effect of inoculum age, oil feed and incubation period to increase sophorolipid yield. The highest yield of sophorolipid by sunflower oil was accomplished with an inoculum age of 60 h. Maximum substrate consumption and sophorolipid yield were found near about 200 h. At optimized fermentation conditions, 19.2 g/L yield of sophorolipid was achieved. The lactonic sophorolipid which is the major component of crude sophorolipid was separated and purified by adsorption chromatography. Normal phase and reverse phase resin were compared for adsorptive purification among which reverse phase resin provides better purification with 69 % recovery. Further surfactant and antimicrobial properties of crude sophorolipid were studied.