Sophorolipids Production by Candida bombicola ATCC 22214 and Its Potential Application in Soil Bioremediation

The sophorolipids are biosurfactants composed by a disaccharide sophorose linked by a hydroxyl group of a fatty acid. Due to their surface-active properties, sophorolipids have a great potential for using in different industrial sectors. They are synthesized by various strains of the genus Candida in the presence of hydrophilic and hydrophobic sources. In this study, it was evaluated the production of sophorolipids by Candida bombicola ATCC 22214 using sugar cane molasses, sugar cane juice, sucrose or glucose as hydrophilic source and chicken fat or sunflower oil as hydrophobic source. The sophorolipids were characterized and applied in bioremediation of soils contaminated with lubricating oil. The production of sophorolipids was 39.81 g L-1 in the optimized condition of 75 g L-1 of chicken fat, 77.5 g L-1 of glucose, 2.5 g L-1 of yeast extract and without urea. The sophorolipids produced present the diacetylated lactonic form, exhibiting the surface tension properties of 35 mN/m and of CMC 65 mg L-1. The sophorolipids showed great emulsification index in lubricant oil, toluene and n-heptane, suggesting the potential application in bioremediation of lubricating-oil-contaminated soils.