Production of sophorolipids from long-chain fatty acids by Candida bombicola

Tall oil, a mixture of long-chain oleic and linoleic acids, was found to be a suitable lipophilic substrate for the production of sophorolipid, an extracellular glycolipid surfactant, by Candida bombicola ATCC 22214. Oxygen limitation was found to decrease sophorolipid production in this system. Partitioning experiments with sophorolipid revealed that the surfactant increases the affinity of oleic acid for the aqueous phase of a two phase system. C. bombicola therefore has potential applications in the remediation of pulp and paper effluent containing recalcitrant long-chain fatty acids; both for its ability to degrade the acids and for the tendency of sophorolipid to make fatty acids more bioavailable to organisms involved in downstream activated sludge treatment. A novel capillary gas chromatography method was developed to rapidly and quantitatively analyze long-chain fatty acids.