|Ashby, Richard - Rick|
Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/14/2005
Publication Date: 5/1/2005
Citation: Solaiman, D., Ashby, R.D., Zerkowski, J.A., Nunez, A., Foglia, T.A. 2005. Production and modification of sophorolipid biosurfactant [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 17.
Technical Abstract: Sophorolipids (SLs) are biosurfactants produced by several yeast species. In Candida bombicola, the hydrophilic moiety of the biosurfactant molecule is a disaccharide (i.e., sophorose), and the hydrophobic portion is an omega- or (omega-1)-hydroxy fatty acid attached to the sophorose via a glycosidic bond. The fatty acid chain, most commonly containing 16- and 18-carbon atoms, may be unsaturated and lactonized to the disaccharide. The potential applications of SLs include serving as environmentally friendly surfactants in oil recovery operation, and as active ingredient in detergent, cosmetic and lubricant formulations. SLs are also known to have antimicrobial activity. However, there is a need to lower the costs of producing SL and to improve its physicochemical and surface-active properties to make its commercialization possible. In this paper, we describe our study on the use of various surplus and low-cost agricultural co-products such as animal fats, plant oils, and soy molasses as fermentative substrates for the production of SL. We showed that the inexpensive soy molasses could serve as substrate with a product yield of 21 g SL/l of culture; that product yield as high as 99 g SL/l of culture could be obtained using oleic acid/glucose as substrates; and that the structure and composition of the products may be varied with the type of substrates used. We will also describe in this presentation the characterization of the genes involved in the biosynthesis of SL for subsequent genetic and metabolic engineering to improve product yields and compositions. Our work on the chemical modification of sophorolipids to improve their solubility and surface-active properties will also be presented.