Immobilization of Trametes versicolor lacease on magnetically separable mesoporous silica spheres

Magnetic mesoporous silica spheres (MSS) with large pore size were prepared by reducing Fe³⁺containing mesoporous silica spheres. Lacease from Trame tes versicolor was immobilized on magnetic mesoporous silica spheres through physical adsorption and covalent attachment methods. Lacease oxidizes 2,2'-azinobis(3-ethylbenzthiazolin-6-sulfonate) (ABTS) to the green cation radical (ABTS"⁺) as a model system; the immobilized lacease retained the activity and exhibited higher resistance to pH changes and thermal stability. The immobilized lacease obtained through covalent attachment almost has no leaching and can retain above 70% of activity after 10 consecutive operations. More interesting, the immobilized lacease can be separated quickly using an external magnetic field. Therefore, the magnetite-containing mesoporous silica spheres are a promising support for enzyme immobilization.