title: Optimization of penicillin G acylase multipoint immobilization on to glutaraldehyde-chitosan beads.
abstract: The objective of this work was to study the immobilization of penicillin G acylase from Escherichia coli on to chitosan-glutaraldehyde beads by multipoint covalent binding. This process was optimized using a 2(3) experimental design. The parameters selected for the present study were the concentrations of glutaraldehyde, phenylacetic acid and sodium borohydride. Three responses were chosen, namely immobilization yield and stabilization factors of enzyme derivatives at high temperature and at alkaline pH. All the runs at the maximum (+1) and minimum (-1) levels were performed at random. Three experiments were performed at the centre point, coded as zero, for experimental-error estimation. With respect to immobilization yield, the main effectors were the concentrations of glutaraldehyde and phenylacetic acid. For stabilization factors at 50 degrees C and at alkaline pH, the main effectors were the concentrations of glutaraldehyde and sodium borohydride and the interaction between them.
authors.affiliation: Departamento de Engenharia Química, Universidade Federal do Ceará, Campus do Pici, Bloco 709, Fortaleza, CE 60455-760, Brazil.
authors.forename: Wellington S
authors.initials: WS
authors.lastname: Adriano
authors.forename: Edilson H C
authors.initials: EH
authors.lastname: Filho
authors.forename: James A
authors.initials: JA
authors.lastname: Silva
authors.forename: Luciana R B
authors.initials: LR
authors.lastname: Gonçalves
mesh_terms: D001665:Binding Sites; D001894:Borohydrides / Q000737:chemistry / Q000378:metabolism; D048271:Chitosan / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005976:Glutaral / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010399:Penicillin Amidase / Q000378:metabolism*; D010648:Phenylacetates / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding
chemical_list: D001894:Borohydrides; D004800:Enzymes, Immobilized; D010648:Phenylacetates; C025364:sodium borohydride; D048271:Chitosan; D010399:Penicillin Amidase; C025136:phenylacetic acid; D005976:Glutaral