Open AccessImmobilization of bromelain on cobalt-iron magnetic nanoparticles (CoFe2O4) for casein hydrolysis
Author(s) -
José Mauricio García Colmenares,
Julia Constanza Reyes Cuellar
Publication year - 2020
Publication title -
revista colombiana de química/revista colombiana de quimica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.139
H-Index - 7
eISSN - 2357-3791
pISSN - 0120-2804
DOI - 10.15446/rev.colomb.quim.v1n49.69474
Subject(s) - bromelain , glutaraldehyde , chemistry , immobilized enzyme , chitosan , hydrolysis , nuclear chemistry , casein , cyclic voltammetry , cobalt , nanoparticle , covalent bond , chromatography , enzyme , electrochemistry , materials science , papain , organic chemistry , nanotechnology , electrode
By means of recycling an enzyme, bromelain was used in casein hydrolysis facilitated by a nanobiocatalyst consisting of bromelain, CoFe2O4 magnetic nanoparticles, chitosan, and glutaraldehyde. Bromelain was immobilized on the chitosan cobalt-magnetite nanoparticle surface via covalent bonds to form the nanobiocatalyst. Immobilized bromelain showed 77% immobilization binding, retaining 85 ± 2% of the initial catalytic activity. Nanoparticles and immobilized bromelain were characterized using UV-Vis and IR spectroscopies, X-ray, square wave voltammetry (SWV), cyclic voltammetry (CV), vibrating-sample magnetization (VSM), and transmission electron microscope (TEM). The Michaelis-Menten constant (KM) and VMAX of the free and immobilized enzyme were calculated: KM = 2.1 ± 0.18 mM and 1.8 mM, respectively and VMAX = 6.08 x 10-2 ± 2.1 x 10-2 U/min and 6.46 ± 0.91 U/min, respectively. The thermal stability of the free enzyme was higher than the immobilized enzyme: 95-98% and 83-87%, respectively. An optimum pH of 6 and a temperature of 20 °C were determined in both cases. Immobilized bromelain maintained 50% of the initial catalytic activity after the fifth use. The immobilized bromelain proved to be effective and reusable for casein hydrolysis. As novel contribution the characterization by VOC and CV was carried out.