The Synthetic Process Of Phosphatidylserine From Soybean Lecithin Catalyzed By Phospholipase D

Phosphatidylserine (PS) is a special kind of rare phospholipids. It has some advantages improve brain function,improve Alzheimer’s disease,and enhance cognitive functioning, and help repair the brain damage, relieve stress, emotional disturbance, the treatment of ADHD, etc.But PS in the content of nature is very rare, and thus the synthesis of phosphatidylserine is very necessary. In this paper, the enzymatic conversion method is the use of phospholipase D transfer characteristics which can catalyze synthesis of phosphatidylserine from soybean lecithin.This required the activity of phospholipase D, so firstly,phospholipase D was bred in natural and mutagenized by UV which caused gene mutations of the strains, so it has the high yield and the transphosphatidylation activity was increased nearly40percent, and the result of the generation stability for phospholipase D strains is better. Although the performance of the strain is an important factor in determining the fermentation effect, the fermentation process conditions for the enzyme production is also very clear. We can optimize the fermentation medium by shake bottled cultivation. The optimal nitrogen source is soybean (Henan), and its concentration is5g/L; the best accelerator is Tween80, and the concentration is0.50g/L;the inorganic salts has CaCl2and NaCl, MgSO4with of3.00g/L,2.00g/L,1.00g/L of concentrations.Since the reaction of the catalytic synthesis of phosphatidylserine is a two-phase reaction, and free phospholipase D is in the aqueous phase, and the inactivation of the phospholipase D was contacted by organic phase, so the reaction is end, it is necessary for the immobilized enzyme which is easily recycled and has a repetition frequency. In the synthesis of phosphatidylserine of small scale experiments, the reaction conditions were optimized: organic solvent is Benzene, volume ratio (organic phase:aqueous phase) is2.5:1, L-serine and soybean lecithin molar ratio is100:1, pH value is5.5-6.0, the reaction temperature is28℃, reaction time is270min. On this base of the reaction,we can simulate the process of the monthly production capacity of6tons of phosphatidylserine by ASPEN PLUS software. Firstly,the most appropriate physical properties were determined, then the each module was designed and selected, and process the material balance and energy balance.Finally,we can carry out the economic evaluation. The results showed that the proceeds of the project an annual output is more than20million RMB and has a feasibility.