关键词: 磷脂酰丝氨酸, 固定化磷脂酶D, 反复分批式反应, 胆碱

Abstract: The synthetic reaction of phosphatidyserine from soybean lecithin catalyzed by immobilized phospholipase D was carried out in oil-water two phase system, with PC and L-serine rich in oil and water phase, respectively. However, the by-product choline restrains the enzyme-catalyzed reaction rate and should be removed in time. In order to solve this problem, we adopted the repeated batch reaction. Increasing the substrate (PC) concentration decreased the yield of PS greatly. When various concentrations of choline chloride were added into the reaction mixture at low PC concentrations, there was a significant decrease in transphosphatidylation rate and the yield of PS. The using of repeated batch reaction was examined at high PC concentration to remove choline, the transphosphatidylation rate increased by 38%, and PS yield was 67%. The paper reported that the repeated batch operation is a novel technology for the synthesis of phosphlipid and increased the productivity of PS significantly. And the immobilized enzyme activity remained 58% after ten batches and nano-SiO₂-immobilized-PLD was suitable for repeated batch reaction.

Key words: phosphatidyserine, immobilized phospholipase D, repeated batch reaction, choline