KINETICS AND THERMODYNAMICS APPROACH FOR IMMOBILIZATION OF ALPHA-AMYLASE AND MALTOGENIC AMYLASE BY NANOMAGNETIC COMBINED CROSS-LINKED ENZYME AGGREGATES METHOD FOR STARCH CONVERSION TO MALTOSE SYRUP
HOMA TORABIZADEH *
Department of Chemical Technologies, Food Science and Technology Group, Iranian Research Organization for Science and Technology (IROST), Mojtama Asre Enghelab Building, Shahid Ehsanirad Street, 33535111, Tehran, Iran.
ENSIEH MONTAZERI
Department of Chemical Technologies, Food Science and Technology Group, Iranian Research Organization for Science and Technology (IROST), Mojtama Asre Enghelab Building, Shahid Ehsanirad Street, 33535111, Tehran, Iran.
*Author to whom correspondence should be addressed.
Abstract
The thermostability enhancement of specified nanomagnetic combi-CLEAs of α-amylase and maltogenic amylase was evaluated by assessment of kinetic parameters, temperature dependence, enzyme half-life, thermal inactivation energy barriers (Ea(in)), and thermodynamic parameters in a storage thermostability approach at 55–95° C for 120 minutes. The Michaelis constant (Km) values of NM-Combi-CLEAs was diminished within 1.5 folds while The catalytic efficiency was enhanced near 1.32 after CLEAs formation. The half-lives of the fabricated nano-bio catalyst increased about 2.5 folds at 95º C. Besides, Ea(in) of the native combined enzymes was appended from 44.75 into 54.76 (KJ.mol-1) and ΔH* increased from 41.69 to 51.70 (KJ.mol-1) while, ΔS* decreased 28.2% after immobilization. The NM-Combi-CLEAs conserved 80.4% of its original activity after ten cycles. Hence, the advanced technique for NM-Combi-CLEAs production is introduced as an effective and secured method to fabrication of recyclable immobilized enzyme also, resolving of mass transfer limitation difficulties and ease in enzyme handling.
Keywords: Alpha-amylase, kinetics and thermodynamics, Maltogenic amylase, Maltose, nanomagnetic combi-CLEAs, starch hydrolysis.