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چکیده
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Cellulose is the most abundant biopolymer .For using of this rich source, it’s necessary to
cellulose be hydrolyzed by chemical or biological method. Biological hydrolysis has less
pollution and more economical importance, so considerable attention has been paid to the
enzymatic hydrolysis like cellulase. Cellulases is one of the most functional enzyme in
different industry. Applications of Cellulase is in textile industry, detergent and paper
industry, the fuel industry [1]. Because of diverse practical applications, cellulase should be
stable over wide pH and temperature ranges. Enzyme Immobilization to solid carriers is the
most used strategy to improve stability of biocatalysts. Use of nanoparticles for
immobilization have an important place. Enzymes immobilized on nanoparticles showed a
broader working pH and temperature range and higher thermal stability than the native
enzymes. Chitosan’s availability and its unique chemical and biological properties like
nontoxicity, biocompability and biodegradability make it a very attractive biomaterial for
enzyme immobilization [2]. In this study, firstly, the AaCel9A endoglucanase was produced
in prokaryotic expression system. The chitosan nanoparticle was synthesized by ionic gelation
method with tripolyphosphate (TPP) and finally the purified AaCel9A enzyme was
immobilized on the chitosan nanoparticles that activated by Glutaraldehyde. Use of SEM and
FTIR techniques confirmed immobilization and immobilizad Enzyme activity was performed
by measuring absorption spectroscopy. The study of optimal temperature for activity of
immobilized enzyme showed that high activity of the enzyme was began at 40 and its
activity was retained to 75 , whereas that for free enzyme was 65 .
The study of biochemical and kinetical properties of immobilized AaCel9A enzyme on
nanoparticles is in process.
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