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Immobilization of α‐amylase onto chitosan and its amino acid condensation adducts
Author(s) -
ElGhaffar M. A. Abd,
Hashem M. S.
Publication year - 2009
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.29292
Subject(s) - chitosan , amylase , chemistry , glutamic acid , adduct , nuclear chemistry , bacillus subtilis , polymer chemistry , amine gas treating , amino acid , chromatography , organic chemistry , biochemistry , enzyme , bacteria , biology , genetics
α‐Amylase from Bacillus subtilis was immobilized on insoluble chitosan and its amino acid ( L ‐glutamic acid and 4‐aminobutyric acid) condensation adducts with the direct covalent attachment method and with glutaric dialdehyde (GDA) as a crosslinking agent. The immobilization process was carried out at 25°C and pH 6.9, and the maximum retained activity was obtained with 3 mg of α‐amylase. The properties of the immobilized α‐amylase were investigated and compared with those of the free α‐amylase. For the assays carried out via the crosslinking method at 25°C and pH 6.9, the retained activities were found to be 68.59, 97.36, and 79.50% for chitosan, chitosan– L ‐glutamic acid, and chitosan–4‐aminobutyric acid crosslinked with 1% GDA, respectively. The immobilized α‐amylase had better stability and higher retained activities with respect to the pH, temperature, and storage stability than the free α‐amylase. In the repeated‐use experiments, the α‐amylase immobilized with chitosan–GDA (1%) retained about 46.45% of its original activity after 25 uses. In contrast, the activities of α‐amylase immobilized on chitosan– L ‐glutamic acid–GDA (1%) and chitosan–4‐aminobutyric acid–GDA (1%) did not change after 11 and 8 uses, respectively. The retained activities after 25 uses were 79 and 71% with respect to the original activity for the aforementioned carriers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009