title: Immobilization of magnetic modified Flavobacterium ATCC 27551 using magnetic field and evaluation of the enzyme stability of immobilized bacteria.
abstract: The magnetic modified Flavobacterium sp. was prepared by covalently binding carboxylate-modified magnetic nanoparticles, and also, ionic adsorption of magnetic Fe(3)O(4) nanoparticles on the cell surface. The magnetic modified bacteria were immobilized by both internal and external magnetic fields. The pH stability and inherent resistance of the enzyme activity of the immobilized bacteria under acidic and alkaline conditions were increased. Immobilization of the magnetic modified bacteria using an external magnetic field improved the enzyme thermal stability. The results revealed that immobilization of the magnetic modified bacteria by an external magnetic field keeps 50% of the enzyme activity after 23.4, 16.6 and 6 h of incubation at 55 °C for the covalently binding of magnetic nanoparticles, the ionic adsorption of magnetic nanoparticles and the free cells, respectively. The results demonstrated the negative effect of various magnetic beads on the enzyme thermal stability of immobilized magnetic modified bacteria using an internal magnetic field.
authors.affiliation: Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, P.O. Box 14115-114, Tehran, Iran.
authors.forename: Seyed Mortaza
authors.initials: SM
authors.lastname: Robatjazi
authors.forename: Seyed Abbas
authors.initials: SA
authors.lastname: Shojaosadati
authors.forename: Rassoul
authors.initials: R
authors.lastname: Khalilzadeh
authors.forename: Ebrahim Vasheghani
authors.initials: EV
authors.lastname: Farahani
authors.forename: Nooshin
authors.initials: N
authors.lastname: Balochi
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology / Q000528:radiation effects; D018914:Cells, Immobilized / Q000502:physiology / Q000528:radiation effects; D004789:Enzyme Activation / Q000528:radiation effects; D004795:Enzyme Stability / Q000187:drug effects; D004798:Enzymes / Q000737:chemistry* / Q000378:metabolism*; D005417:Flavobacterium / Q000201:enzymology* / Q000528:radiation effects*; D018189:Immunomagnetic Separation / Q000379:methods*; D060526:Magnetic Fields
chemical_list: D004798:Enzymes