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Cyanuric chloride functionalized silica nanoparticles for covalent immobilization of lipase
Author(s) -
Banjanac Katarina,
Mihailović Mladen,
Prlainović Nevena,
Stojanović Marija,
Carević Milica,
Marinković Aleksandar,
Bezbradica Dejan
Publication year - 2016
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4595
Subject(s) - cyanuric chloride , lipase , chemistry , immobilized enzyme , adsorption , covalent bond , thermogravimetric analysis , thermal stability , nuclear chemistry , chromatography , organic chemistry , enzyme
BACKGROUND In this work, fumed nano‐silica ( FNS ) was chemically modified to amino ( AFNS ) and subsequently to cyanuric chloride ( CCAFNS ) modified silica and tested for the immobilization of lipase from Candida rugosa ( CRL ). The effects of the initial enzyme concentration, immobilization time and buffer ionic strength on immobilization were investigated in order to optimize utilization of the support and determine the mechanism of immobilization. The most active preparations were used to examine thermal and operational stability. RESULTS The amount of immobilized enzyme increased with increasing enzyme concentration, achieving loadings of 121.3, 104.8 and 61.2 mg per g of FNS , CCAFNS and AFNS , respectively. Lipase immobilized on CCAFNS carrier in 0.1 mol L −1 buffer expressed the highest lipolytic activity (1320 IU g −1 support), while more stable preparations were obtained in 1 mol L −1 buffer. CONCLUSION Successful modification of silica was confirmed with Fourier transform infrared spectroscopy and thermogravimetric analysis. Activity results showed that, depending on the support, immobilization was governed by different interactions. On FNS and AFNS immobilization was exclusively by adsorption, while on CCAFNS after the initial adsorption lipase molecules reoriented and amino groups of the enzyme formed a covalent bond with the chlorine atom of the modified carrier. Improved thermal and operational stability of lipase immobilized on CCAFNS in 1 mol L −1 buffer led to the conclusion that electrostatic interactions have a great role in the immobilization. © 2014 Society of Chemical Industry