초록
This paper describes the use of immobilized phospholipase A1 (PLA1) for the production of phosphatidylcholine (PC) rich in docosahexaenoic acid (DHA) using PC from Antarctic krill and fish fatty acids (FA) as the substrates, and supercritical carbon dioxide (SCCO<SUB>2</SUB>) as the solvent medium. Detailed studies of immobilization were performed, and PLA1 was immobilized by physical adsorption onto DA-201. The best conditions for adsorption were as follows: protein loading=85mg PLA1/g support at a pH of 5 with 10h of contact. For synthesis of PC with high levels of DHA, the effects of several parameters, including pressure, reaction time, temperature, enzyme loading and substrate molar ratio, were investigated to determine optimal conditions. The optimal substrate molar ratio of the FA to PC was 10. Under 12MPa and 50<SUP>o</SUP>C SCCO<SUB>2</SUB>, 59.0mol% DHA was incorporated into PC after only 7h at an immobilized enzyme loading rate of 15wt% of the total substrates. The PC yield was 27.5mol% under the optimal conditions.