酶法合成富含二十二碳六烯酸的磷脂酰丝氨酸

The Enzymatic Synthesis of Docosahexaenoic Acid being Rich in Phosphatidylserine

通过以鱿鱼卵磷脂和L-丝氨酸为原料,对磷脂酶D催化酰基转移反应制备磷脂酰丝氨酸(phosphatidylserine,PS)的工艺条件进行探索,并进行了优化试验,确定反应的最佳工艺。通过单因素试验法分别探讨有机相种类、反应温度、水相p H、有机相水相体积比、底物质量比、酶量、反应时间等因素对PS合成率的影响,得到初步优化条件。之后,做四因素三水平的正交试验,优化制备PS的工艺条件。最优工艺条件:水相p H4.5、有机相水相体积比5∶6、反应温度40℃、酶量40 U、底物质量比1∶32、反应时间6 h。在该条件下PS合成率为97.65%,DHA含量为33.10%。

The enzymatic synthesis of phosphatidylserine enriched in docosahexaenoic acid（DHA） from squid egg lecithin and L-serine was examined with the transphosphatidylation of phospholipase D（PLD）. Experiments were conducted to get the optimal conditions. Firstly, they found that PS synthesis is significantly affected by the amount of PLD, the amount ratio of squid egg lecithin to L-serine, reaction temperature and reaction time by single-factor tests. Then an orthogonal test of four factors and three levels is developed based on single-factor tests. Finally they get the optimal conditions： 20 m M acetate buffer of pH 4.5, ethyl acetate volume to acetate buffer volume ratio of 5 ∶6, reaction temperature40 ℃, PLD amount of 40 U, squid egg lecithin to L-serine ratio of 1∶32, reaction time 6 h. PS content in the recovered phospholipid fraction increased to 97.65% under the optimal reaction conditions with the content of DHA up to33.10%.