کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
638579 1456179 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Immobilization of lipase with a special microstructure in composite hydrophilic CA/hydrophobic PTFE membrane for the chiral separation of racemic ibuprofen
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Immobilization of lipase with a special microstructure in composite hydrophilic CA/hydrophobic PTFE membrane for the chiral separation of racemic ibuprofen
چکیده انگلیسی

The asymmetric hydrolyzation of racemic ibuprofen ester catalyzed by lipase is one of the most important methods for the chiral separation of ibuprofen. In this work, a special microstructure in the composite hydrophilic cellulose acetate (CA)/hydrophobic polytetrafluoroethylene (PTFE) membrane was designed for lipase immobilization by ultrafiltration. A biphasic enzymatic membrane reactor (EMR) and an emulsion reaction system with free lipase were both used, and the activity, enantioselectivity selectivity and half-life of immobilized and free enzymes were compared. The morphology of the composite membrane and the position of the entrapment in the microstructure of composite membrane where lipase were immobilized were observed by scanning electron microscopy (SEM). The effects of substrate concentration, enzyme loading, reaction temperature and pH on the separation were investigated. The experimental results showed that the lipase was entrapped at the interface of the composite membrane, which is consistent with the interface of aqueous phase and organic phase. Because the immobilized enzyme by our new method did not destroy the enzyme structure, it retained higher activity; the enzyme activity was more than 60% compared to the free lipase when enzyme loading was under 1 g-protein/m2. Meanwhile, the immobilized enzyme provided better chiral selectivity (up to 83.5% eep) and a longer half-life (about 183.3 h in our work compared to 94 h as reported by other researcher). High enzyme activity and chiral selectivity were obtained with a substrate concentration of 0.35 M, enzyme loading of 0.7–1.0 g-protein/m2 at aqueous phase pH 8.0 and a temperature of 40 °C.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Membrane Science - Volume 293, Issues 1–2, 20 April 2007, Pages 133–141
نویسندگان
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