Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Activity stabilization of Aspergillus niger and Escherichia coli phytases immobilized on allophanic synthetic compounds and montmorillonite nanoclays
AU - Menezes-Blackburn, Daniel
AU - Jorquera, Milko
AU - Gianfreda, Liliana
AU - Rao, Maria
AU - Greiner, Ralf
AU - Garrido, Elizabeth
AU - de la Luz Mora, María
N1 - Copyright © 2011. Published by Elsevier Ltd.
PY - 2011/10
Y1 - 2011/10
N2 - The aim of this work was to study the stabilization of the activity of two commercial microbial phytases (Aspergillus niger and Escherichia coli) after immobilization on nanoclays and to establish optimal conditions for their immobilization. Synthetic allophane, synthetic iron-coated allophanes and natural montmorillonite were chosen as solid supports for phytase immobilization. Phytase immobilization patterns at different pH values were strongly dependent on both enzyme and support characteristics. After immobilization, the residual activity of both phytases was higher under acidic conditions. Immobilization of phytases increased their thermal stability and improved resistance to proteolysis, particularly on iron-coated allophane (6% iron oxide), which showed activation energy (E(a)) and activation enthalpy (ΔH(#)) similar to free enzymes. Montmorillonite as well as allophanic synthetic compounds resulted in a good support for immobilization of E. coli phytase, but caused a severe reduction of A. niger phytase activity.
AB - The aim of this work was to study the stabilization of the activity of two commercial microbial phytases (Aspergillus niger and Escherichia coli) after immobilization on nanoclays and to establish optimal conditions for their immobilization. Synthetic allophane, synthetic iron-coated allophanes and natural montmorillonite were chosen as solid supports for phytase immobilization. Phytase immobilization patterns at different pH values were strongly dependent on both enzyme and support characteristics. After immobilization, the residual activity of both phytases was higher under acidic conditions. Immobilization of phytases increased their thermal stability and improved resistance to proteolysis, particularly on iron-coated allophane (6% iron oxide), which showed activation energy (E(a)) and activation enthalpy (ΔH(#)) similar to free enzymes. Montmorillonite as well as allophanic synthetic compounds resulted in a good support for immobilization of E. coli phytase, but caused a severe reduction of A. niger phytase activity.
KW - 6-Phytase
KW - Aluminum Silicates
KW - Aspergillus niger
KW - Bentonite
KW - Enzymes, Immobilized
KW - Escherichia coli
KW - Nanotechnology
KW - Proteolysis
KW - Temperature
KW - Thermodynamics
KW - X-Ray Diffraction
U2 - 10.1016/j.biortech.2011.07.054
DO - 10.1016/j.biortech.2011.07.054
M3 - Journal article
C2 - 21856150
VL - 102
SP - 9360
EP - 9367
JO - Bioresource Technology
JF - Bioresource Technology
SN - 0960-8524
IS - 20
ER -