Development of enzymatically-active bacterial cellulose membranes through stable immobilization of an engineered β-galactosidase

Enzymatically-active bacterial cellulose (BC) was prepared by non-covalent immobilization of a hybrid enzyme composed by a β-galactosidase from Thermotoga maritima (TmLac) and a carbohydrate binding module (CBM2) from Pyrococcus furiosus. TmLac-CBM2 protein was bound to BC, with higher affinity at p...

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Bibliographic Details
Authors: Estevinho, Berta N., Samaniego, Nuria, Talens Perales, David, Fabra, María José, López-Rubio, Amparo, Polaina Molina, Julio, Marín Navarro, Julia
Format: article
Status:Versión aceptada para publicación
Publication Date:2018
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/171743
Online Access:http://hdl.handle.net/10261/171743
Access Level:Open access
Keyword:Protein immobilization
Carbohydrate binding module
Bacterial cellulose
Description
Summary:Enzymatically-active bacterial cellulose (BC) was prepared by non-covalent immobilization of a hybrid enzyme composed by a β-galactosidase from Thermotoga maritima (TmLac) and a carbohydrate binding module (CBM2) from Pyrococcus furiosus. TmLac-CBM2 protein was bound to BC, with higher affinity at pH 6.5 than at pH 8.5 and with high specificity compared to the non-engineered enzyme. Both hydrated (HBC) and freeze-dried (DBC) bacterial cellulose showed equivalent enzyme binding efficiencies. Initial reaction rate of HBC-bound enzyme was higher than DBC-bound and both of them were lower than the free enzyme. However, enzyme performance was similar in all three cases for the hydrolysis of 5% lactose to a high extent. Reuse of the immobilized enzyme was limited by the stability of the β-galactosidase module, whereas the CBM2 module provided stable attachment of the hybrid enzyme to the BC support, after long incubation periods (3 h) at 75 °C.