Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China.
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, The College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China.
Int J Biol Macromol. 2021 Feb 1;169:282-289. doi: 10.1016/j.ijbiomac.2020.12.103. Epub 2020 Dec 15.
Transphosphatidylation catalyzed by phospholipase D has gained increasing attention for producing phosphatidylserine (PS), which can be used in functional food and medicine. In this study, we investigated the effects of six signal peptides on the secretion of PLD (PLD) from Streptomyces antibioticus TCCC 21059 in the food-grade GRAS bacterium Bacillus subtilis. It indicated that the optimal signal peptide DacB with an Ala-X-Ala sequence motif at the C-terminus showed the highest secretory expression ability, resulting in increased production of 2.84 U/mL PLD. Then PLD was immobilized on the epoxy-based carriers, and one of these carriers allowed PLD loading of up to 2.7 mg/g. The immobilized PLD was more stable over a wide range of pH value (4.5-7.5) and temperature (16 °C-60 °C) than free PLD. Subsequently, the synthesis of PS from soybean phosphatidylcholine (PC) was carried out in purely aqueous solution using immobilized PLD, leading to a high yield of 65%. The immobilized PLD catalyst maintained a relative PS production of 60% after 5 recycles. Notably, the use of toxic solvent was completely eliminated in the whole process, which would be more profitable for the application of PS.
磷脂酶 D 催化的转磷酸化作用越来越受到关注，因为它可以生产磷脂酰丝氨酸 (PS)，PS 可用于功能性食品和药物。在本研究中，我们研究了六种信号肽对食源性 GRAS 细菌枯草芽孢杆菌中链霉菌抗生素 21059 来源的 PLD（PLD）分泌的影响。结果表明，具有 Ala-X-Ala 序列基序的最优信号肽 DacB 在 C 端具有最高的分泌表达能力，导致 PLD 产量增加到 2.84 U/mL。然后将 PLD 固定在基于环氧的载体上，其中一种载体允许 PLD 负载高达 2.7 mg/g。与游离 PLD 相比，固定化 PLD 在更宽的 pH 值（4.5-7.5）和温度（16°C-60°C）范围内更稳定。随后，在纯水溶液中使用固定化 PLD 从大豆卵磷脂 (PC) 合成 PS，得到 65%的高收率。固定化 PLD 催化剂在 5 次循环后仍保持相对 PS 产量的 60%。值得注意的是，整个过程完全消除了有毒溶剂的使用，这将更有利于 PS 的应用。
