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ARS Home » Research » Publications at this Location » Publication #157101


item Nunez, Alberto
item Ashby, Richard - Rick
item Foglia, Thomas
item Solaiman, Daniel

Submitted to: Biotechnology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2004
Publication Date: 7/1/2004
Citation: Nunez, A., Ashby, R.D., Foglia, T.A., Solaiman, D. 2004. LC/MS analysis and lipase modification of the sophorolipids produced by rhodotorula bogoriensis. Biotechnology Letters. 26:1087-1093.

Interpretive Summary: Fats and oils are abundantly produced in the United States but their domestic food usage has remained relatively stagnant. Accordingly, new non-food uses for these commodities need to be developed. Environmentally friendly biotechnological approaches can transform these agricultural materials to higher value-added products with potential industrial utilization. In this study, the extracellular bioemulsifiers produced by yeast were analyzed for the first time using modern technology. The characterized products were subjected to further enzymatic transformation to explore the ability of producing biopolymers of industrial interest. This study demonstrated the incorporation of fatty acids into the structure of these bioemulsifiers and provided the basis for potential industrial application of these materials. The growth of the yeast under appropriate conditions demonstrated the utilization of fats and oils for the production of new environmental friendly materials of interest.

Technical Abstract: The extracellular glycolipids produced by the yeast Candida bogoriensis were analyzed using an LC/API-MS method. The analysis confirmed the sophorolipid structure of these bio-surfactants that incorporated a C22 hydroxy carboxylic acid. Also, it was found that a small portion of the total product had a C24 hydroxy fatty acid moiety not previously reported. The sophorolipid mixture with different degrees of acetylation at the primary alcohols of the sophorose portion was deacetylated and esterified in tetrahydrofuran using an immobilized lipase catalyst. The lipase product was screened for dimer or polymer formation using mass spectrometric techniques, but only a lactonized cyclic dimer was detected as product.