Abstract
Candida antarctica lipase B (CALB) and Thermomyces lanuginosa lipase (TLL) encapsulated in reverse micelles of sodium bis(2-ethylhexyl) phosphate (NaDEHP) were used to investigate the role of different enzymes, effects of water-to-surfactant molar ratio (Wo) and fatty acids (caprylic acid and oleic acid) in catalytic activity of esterification of fatty with hexanol. The reverse micellar system consisted of NaDEHP, hexanol, fatty acid in isooctane and 1.0M NaCl aqueous system. In the NaDEHP reverse micellar system, the optimum Wo of CALB was 6.67 and 7.08 for oleic acid and caprylic acid, respectively, while the optimum Wo of TLL was 8.44 for oleic acid and 9.12 for caprylic acid, respectively. The water-to-surfactant molar ratio, type and concentration of substrate have strong effects to the specific activity of both lipases and the conversion of the reactions. Both CALB and TLL showed the selectivity regarding to long chain fatty acid, however, encapsulated CALB gave higher specific activity and conversion than the encapsulated TLL.
