|Ashby, Richard - Rick|
Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2004
Publication Date: 5/1/2004
Citation: Solaiman, D., Ashby, R.D., Nunez, A., Foglia, T.A. 2004. Fermentative production of biosurfactants from agricultural lipids and byproducts [abstract]. Annual Meeting of the American Oil Chemists' Society. p. 156.
Technical Abstract: Sophorolipids (SLs) are biosurfactants produced by several Candida species. They are composed of a disaccharide (i.e., sophorose) attached to an omega- or (omega-1)-hydroxy fatty acid through a glycosidic bond; the fatty acid moiety may or may not be lactonized to the sophorose entity. The extracellular glycolipids have found applications as bio-based surfactants in oil recovery operation and in the formulation of detergents, cosmetics and lubricants. The materials also possess excellent antimicrobial activity against certain organisms. Candida bombicola is the most studied SL-producing organism because of its ability to produce the biosurfactant in large quantities. Co-feeding of carbohydrate and fatty acid substrates is essential to achieve a high-yield SL production by C. bombicola. This property provides an opportunity to develop renewable agricultural fats, oils and coproducts as feedstocks for SL production. In this paper, we describe the use of tallow oil, soybean oil and linseed oil as the lipid substrates in the fermentative production of SL by C. bombicola. Product yields as high as 50 g SL/L of culture were obtained. The chain length and degree of saturation of the fatty acid moiety of the SLs varied with different lipid substrate, but a large portion (>80%) of the product contained a lactonized fatty acid moiety. A crude glycerol fraction derived from biodiesel manufacturing was tested as a substrate for SL production. The results showed that the fraction of the SLs containing the un-lactonized fatty acid moiety was markedly increased to 75%. We also studied the use of the low-cost soy molasses as a carbohydrate source for SL production. The results indicated that when soy molasses was used in conjunction with oleic acid as the lipid substrate, SL production at 21 g/L of culture could be obtained. In summary, the present work shows that agricultural fats and oils and their low-cost coproducts are suitable feedstocks for use in the production of SLs and for tailoring the composition of the biosurfactant.