Enhanced production of bioactive sophorolipids by Starmerella bombicola NRRL Y-17069 by design of experiment approach with successive purification and characterization

Abstract

In present study, fermentative production of Sophorolipids (SLs) by Starmerella bombicola NRRL Y-17069 that have antibacterial activities was optimized. The media components like glucose, yeast extract and urea were critical components in the microbial growth and formation of SL moiety. The secondary carbon; oleic acid supports the formation of SLs. These components were optimized for maximum production of total SLs which have potential application. Optimization by one factor at-a-time method, glucose and yeast extract were found to be best sources for maximum production of SLs (g/L), 20.94 and 32.1 resp. Oleic acid (100 g/L) gave maximum production of 54.16 g/L with 54 % conversion of added oleic acid in fermentation media indicating fed batch operation is best for SLs production. Total sophorolipids formed were purified and 98.1% lactonic form was obtained by crystallization. Characterization of lactonic SLs by FT-IR, NMR and attached fatty acid moiety was confirmed by GCMS. © 2012 by Japan Oil Chemists' Society.