Efficient synthesis of DHA/EPA-rich phosphatidylcholine by inhibition of hydrolysis reaction using immobilized phospholipase A1 on macroporous SiO2/cationic polymer nano-composited support

Novel nano-composites were prepared by coating epoxy resin-based cationic polymer in nano-thickness via in-situ curing on the wall of macroporous SiO 2 with pore size of 0.5∼1 μm. By changing the thickness of polymer coating the porosity and specific surface area varied in range of 90.4∼83.9 % and 115∼74 m 2 /g, respectively. Through electrostatic adsorption phospholipase A 1 (PLA 1 ) was efficiently immobilized on the nano-composited support, the loading amount of PLA 1 on the nano-composited support reached to a maximum of 138.6 mg/g support , the specific activity of the immobilized PLA 1 reached as high as 21,300 U/g protein . The immobilized PLA 1 was applied for the highly efficient synthesis of DHA/EPA-rich phosphatidylcholine . The incorporation of DHA/EPA reached as high as 74.8 % and the yield of phosphatidylcholine (PC) was 83.1 % within 20 h at 60 °C using PC/ethyl esters mass ratio of 1:6. After 12 cycling reuses the immobilized PLA 1 still retained 57.8 % of the incorporation of DHA/EPA.