Novel magnetic nanoparticles for the hydrolysis of starch with Bacillus licheniformis α‐amylase
Makaleler > Tam Makale · 2011
Yazarlar: Deniz Aktaş Uygun, Nevra Öztürk, Sinan Akgöl, Adil Denizli
Journal of Applied Polymer Science, Uluslararası, Wos, 2011, cilt 123, ss 2574-2581
DOI: 10.1002/app.33879
Özet
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 methacrylate–N‐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 × 10−3 mmol/g of nanoparticles. Then, magnetic nano‐poly[2‐hydroxyethyl methacrylate–N‐methacryloyl‐(L)‐phenylalanine] nanoparticles were used in the adsorption of Bacillus licheniformis α‐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. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012