Preparation and characterization of magnetic levan particles as matrix for trypsin immobilization

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 7; pp. 1312 - 1316
• Main Authors: Maciel, J.C., Andrad, P.L., Neri, D.F.M., Carvalho, L.B., Cardoso, C.A., Calazans, G.M.T., Albino Aguiar, J., Silva, M.P.C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2012; Elsevier
• Subjects: Biological and medical sciences; Biotechnology; Diffraction; Enzyme engineering; Fundamental and applied biological sciences. Psychology; Immobilization; Levan; Levans; Magnetic particle; Magnetite; Magnetization; Matrices; Methods. Procedures. Technologies; Miscellaneous; Scanning electron microscopy; Trypsin; Trypsin immobilization; Levan; Magnetic particle; Trypsin immobilization; Scanning electron microscopy; Magnetization; Frontier orbital; Chemical bond; Immobilization; X ray diffraction; Chemical modification; Magnetic particles; Bacteria; Oxidation; Fourier-transformed infrared spectrometry; Zymomonas mobilis
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2011.11.017

Magnetic levan was synthesized by co-precipitating D-fructofuranosyl homopolysaccharide with a solution containing Fe2+ and Fe3+ in alkaline conditions at 100°C. The magnetic levan particles were characterized by scanning electron microscopy (SEM), magnetization measurements, X-ray diffractometry (XRD) and infrared spectroscopy (IR). Afterwards, magnetic levan particles were functionalized by NaIO4 oxidation and used as matrices for trypsin covalent immobilization. Magnetite and magnetic levan particles were both heterogeneous in shape and levan–magnetite presented bigger sizes compared to magnetite according to SEM images. Magnetic levan particles exhibited a magnetization 10 times lower as compared to magnetite ones, probably, due to the coating layer. XRD diffractogram showed that magnetite is the dominant phase in the magnetic levan. Infrared spectroscopy showed characteristics absorption bands of levan and magnetite (O–H, C–O–C and Fe–O bonds). The immobilized trypsin derivative was reused 10 times and lost 16% of its initial specific activity only. Therefore, these magnetic levan particles can be proposed as an alternative matrices for enzyme immobilization. ► The magnetic levan particles presented larger size variation than magnetite particles due to the changes produced by coating. ► The utilization of magnetic levan particles showed to be efficacious for immobilization of enzymes as trypsin. ► Magnetic particles can be planned as other matrix for immobilization of biomolecule in various division processes in biotechnology.