Immobilization of Dextransucrase from Leuconostoc mesenteroides NRRL B-512F on Eupergit C Supports
详细信息 查看全文
- 作者：Ará ; nzazu Gó ; mez de Segura ; Miguel Alcalde ; Malcolm Yates ; M. Luisa Rojas-Cervantes ; Nieves Ló ; pez-Corté ; s ; Antonio Ballesteros ; and Francisco J. Plou
- 刊名：Biotechnology Progress
- 出版年：2004
- 出版时间：October 2004
- 年：2004
- 卷：20
- 期：5
- 页码：1414 - 1420
- 全文大小：94K
- 年卷期：v.20,no.5(October 2004)
- ISSN：1520-6033
文摘
Dextransucrase from Leuconostoc mesenteroides B-512F was immobilized on epoxy-activated acrylic polymers with different textural properties (Eupergit C and EupergitC 250L). Prior to immobilization, dextransucrase was treated with dextranase toremove the dextran layer covering the enzyme surface, thus increasing the accessibilityof its reactive groups to the epoxide centers of the support. Elimination of 99% of theinitial carbohydrate content was determined by the anthrone method. To preventenzyme inactivation, the immobilization was carried out at pH 5.4, at which thecoupling to the support took place through the carboxylic groups of the enzyme. Theeffects of the amount (mg) of dextransucrase added per gram of support (from 0.2:1 to30:1), temperature and contact time were studied. Maximum activity recovery of 22%was achieved using Eupergit C 250L. Using this macroporous support, the maximumspecific activity (710 U/g biocatalyst) was significantly higher than that obtained withthe less porous Eupergit C (226 U/g biocatalyst). The dextransucrase immobilized onEupergit C 250L showed similar optimal temperature (30 
ges/entities/deg.gif">C) and pH (5-6) comparedwith the native enzyme. In contrast, a notable stabilization effect at 30 ges/entities/deg.gif">C was observedas a consequence of immobilization. After a fast partial inactivation, the dextransucraseimmobilized on Eupergit C 250L maintained more than 40% of the initial activityover the following 2 days. The features of this immobilized system are very attractivefor its application in batch and fixed-bed bioreactors.