Submitted to: Biotechnology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2004
Publication Date: 8/1/2004
Citation: Solaiman, D., Ashby, R.D., Nunez, A., Foglia, T.A. 2004. Production of sophorolipids using soy molasses as substrate. Biotechnology Letters. 26:1241-1245. Interpretive Summary: Sophorolipids (SLs) are biological detergents (biosurfactants) produced by certain yeasts. They are useful in the formulation of cleaning solutions, thickening agents, and antimicrobial creams. The components of the SL molecules are also valued as starting materials for making industrial products such as plastics and biologically active compounds. There is a need to lower the production cost of SL to make it more affordable to consumers. When making SL, the yeast cells must be fed both a sugar and oil feedstock. In this study, we tested an inexpensive feedstock called soy molasses (SM) as the sugar feedstock for SL production. SM is a coproduct stream of soy oil processing. The results showed that SM could in fact support the production of SL. The composition and detergent properties of the SL obtained from our study are compatible to those of SLs produced using more expensive sugar. This work thus laid the groundwork for future research to produce SL in large quantities using the inexpensive soy molasses.
Technical Abstract: Sophorolipids (SLs) were produced from Candida bombicola using soy molasses and oleic acid as the co-substrates. The purified SLs were obtained at 21 g per L of starting culture volume under the experimental conditions used in this study. The major SL constituent (81.3% relative abundance) of the product mixture was a lactone containing a C18:1 fatty acid chain. The surface properties of the SLs obtained from the soy molasses/oleic acid fermentation had minimum surface-tension values of 37.1 mN/m (pH 6) and 38.0 mN/m (pH 9), and critical micelle concentration values of 6.23 mg/L (pH 6) and 12.74 mg/L (pH 9).