Novel magnetic nanoparticles for the hydrolysis of starch with Bacillus licheniformis alpha-amylase


AKTAŞ UYGUN D., Ozturk N., AKGÖL S., DENİZLİ A.

JOURNAL OF APPLIED POLYMER SCIENCE, vol.123, no.5, pp.2574-2581, 2012 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 123 Issue: 5
  • Publication Date: 2012
  • Doi Number: 10.1002/app.33879
  • Title of Journal : JOURNAL OF APPLIED POLYMER SCIENCE
  • Page Numbers: pp.2574-2581

Abstract

Novel magnetic nanoparticles with an average size of 350-400 nm with N-methacryloyl-(L)-phenylalanine (MAPA) as a hydrophobic monomer were prepared by the surfactant-free emulsion polymerization of 2-hydroxyethyl methacrylate, MAPA, and magnetite in an aqueous dispersion medium. MAPA was synthesized from methacryloyl chloride and L-phenylalanine methyl ester. The specific surface area of the nonporous magnetic nanoparticles was found to be 580 m2/g. Magnetic poly[2-hydroxyethyl methacrylateN-methacryloyl-(L)-phenylalanine] nanoparticles were characterized by Fourier transform infrared spectroscopy, electron spin resonance, atomic force microscopy, and transmission electron microscopy. Elemental analysis of MAPA for nitrogen was estimated as 4.3 x 10-3 mmol/g of nanoparticles. Then, magnetic nano-poly[2-hydroxyethyl methacrylateN-methacryloyl-(L)-phenylalanine] nanoparticles were used in the adsorption of Bacillus licheniformis a-amylase in a batch system. With an optimized adsorption protocol, a very high loading of 705 mg of enzyme/g nanoparticles was obtained. The adsorption phenomena appeared to follow a typical Langmuir isotherm. The inverse of enzyme affinity for free amylase (181.82 mg/mL) was higher than that for immobilized enzyme (81.97 mg/mL). Storage stability was found to increase with adsorption. It was observed that the enzyme could be repeatedly adsorbed and desorbed without a significant loss in the adsorption amount or enzyme activity. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012