Lee P M, Lee K H, Siaw Y S
Department of Chemistry, Indiana University, ITM/MUCIA, Shah Alam, Selangor, Malaysia.
Biomater Artif Cells Immobilization Biotechnol. 1993;21(4):563-70. doi: 10.3109/10731199309117658.
Aminoacylase I (E.C.3.5.1.14) was immobilized by entrapment in calcium alginate beads coated with polyethyleneimine for the production of L-phenylalanine by the hydrolysis of a racemic mixture of N-acetyl-DL-phenylalanine. The operational stability in terms of batch operation and continuous reaction in packed-bed bioreactor were studied. Kinetic constants, Km and Vmax values of free and immobilized enzymes were studied. Polyethyleneimine treatment was found to enhance the operational stability of the enzyme though its activity was substantially reduced. When polyethyleneimine-coated calcium alginate beads were packed into packed bed bioreactor, it was stable for at least 25 days under continuous operation without appreciable loss of activity.
氨基酰化酶I（E.C.3.5.1.14）通过包埋在涂有聚乙烯亚胺的海藻酸钙珠粒中进行固定化，用于通过水解N-乙酰-DL-苯丙氨酸的外消旋混合物来生产L-苯丙氨酸。研究了其在分批操作和填充床生物反应器连续反应方面的操作稳定性。研究了游离酶和固定化酶的动力学常数、米氏常数（Km）和最大反应速度（Vmax）值。发现聚乙烯亚胺处理可提高酶的操作稳定性，尽管其活性大幅降低。当将涂有聚乙烯亚胺的海藻酸钙珠粒填充到填充床生物反应器中时，在连续操作下它至少稳定25天，且活性没有明显损失。
