Extraction ofCandida rugosa lipase from aqueous solutions into organic solvents by forming an ion-paired complex with AOT

Abstract

Candida rugosa lipase was extracted from aqueous solutions into organic solvents by forming an ion-paired complex with sodium bis(2-ethylhexyl)sulfosuccinate (AOT). The optimal aqueous pH for lipase recovery was 4.5 and the optimal CaCl2 concentration was 10 mmol dm−3. The lipase recovery decreased with increasing aqueous enzyme concentration but increased with increasing AOT concentration in the organic phase. The presence of polar co-solvents in the aqueous phase did not obviously improve the lipase recovery, which was also little influenced by the type of hydrophobic organic solvent used for solubilising AOT. Surprisingly, no detectable activity of the ion-paired C. rugosa lipase was observed for both the esterification of lauric acid with 1-propanol in isooctane and the hydrolysis of olive oil in isooctane containing an appropriate amount of water. The ion-paired C. rugosa lipase mediated the enantioselective crystallisation of racemic ketoprofen in isooctane, indicating the feasibility of using it as a chiral mediator for the enantioseparation of hydrophobic racemic compounds in organic systems. Copyright © 2006 Society of Chemical Industry