EVALUATION OF SOPHOROLIPID BIOSURFACTANT PRODUCTION BY CANDIDA-BOMBICOLA USING ANIMAL FAT

The meat processing industry is seeking new applications for abundantl y available, inexpensive animal fats. Sophorolipid production by Candi da bombicola was studied as a model for fat utilization for biosurfact ant production. Inoculum medium components (glucose, animal fat, ammon ium sulfate, corn steep liquor urea and potassium phosphate) were opti mized for rapid growth. Similar components were chosen to design a pro duction medium for sophorolipid production. Corn steep liquor provided vitamins and minerals, and fat plus glucose were used as carbon sourc es. Maximum growth was obtained at 30 degrees C but greater sophorolip id production occurred at 27 degrees C. In a pH-controlled fermenter ( maintained at pH 3.4 after the first 24 hours) 120 g l(-1) of sophorol ipid was obtained in 68 h. Silica gel column chromatography of the ext racted sophorolipid revealed the presence of at least six components, including a major component comprising 45% of the total sophorolipids. Cells at the end of fermentation contained 37% protein and 14% lipids . Amino acid analysis indicated a high quality of protein, although wi th a lower than desired tryptophan level A reduction in production tim e with high volumetric productivity and inexpensive raw materials make sophorolipid competitive against surfactants used in the food and cos metics industries.