OPTIMIZATION OF FERMENTATIVE PRODUCTION OF SOPHOROLIPID BIOSURFACTANT BY STARMERELLA BOMBICOLA NRRL Y-17069 USING RESPONSE SURFACE METHODOLOGY

Abstract

Sophorolipids (SLs) are glycolipids type of biosurfactants and are produced by few of the nonpathogenic yeast species like Starmerella bombicola. In the present work, statistical experimental methodology was used to optimize the fermentative production of SLs from Starmerella Bombicola NRRL Y-17069 at the shake flask scale. The Placket–Burman screening experiments was applied to evaluate the significant variables that influence the production of Sophorolipids. It was found that pH, concentration of Yeast extract and the Concentration of Oleic acid are the most influential variables that affected the production of Sophorolipids. The optimum levels of these three variables were achieved by using a Box-Behnken design of the response surface methodology (RSM). The predicted maximal sophorolipid production of 18.32 g/L appeared at pH 3, and when the concentrations of yeast extract and oleic acid were 5 g/L, and 20 g/L, respectively. Under the proposed optimized conditions, the sophorolipid production reached 18.2 g/L. The correlation between predicted value and measured value of these experiments proved the validity of the response model.