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 - Production of partially phosphorylated myo-inositol phosphates using phytases immobilised on magnetic nanoparticles
AU - Greiner, Ralf
AU - Konietzny, Ursula
AU - Blackburn, Daniel Menezes
AU - Jorquera, Milko A.
N1 - Copyright © 2013 Elsevier Ltd. All rights reserved.
PY - 2013/8
Y1 - 2013/8
N2 - Phytases of different origin were covalently bound onto Fe3O4 magnetic nanoparticles (12 nm). Binding efficiencies of all three phytases were well above 70% relative to the number of aldehyde groups available on the surface of the magnetic nanoparticles. Temperature stability for all three phytases was enhanced as a consequence of immobilisation, whereas pH dependence of enzyme activity was not affected. Maximum catalytic activity of the immobilised phytases was found at 60°C (rye), 65°C (Aspergillus niger) and 70°C (Escherichia albertii). The immobilised enzymes exhibited the same excellent substrate specificities and unique myo-inositol phosphate phosphatase activities as their soluble counterparts. However, the catalytic turnover number dropped drastically for the immobilised phytases. The amount of the desired partially phosphorylated myo-inositol phosphate isomer could be easily controlled by the contact time of substrate solution and immobilised enzymes. The immobilised phytases showed a high operational stability by retaining almost full activity even after fifty uses.
AB - Phytases of different origin were covalently bound onto Fe3O4 magnetic nanoparticles (12 nm). Binding efficiencies of all three phytases were well above 70% relative to the number of aldehyde groups available on the surface of the magnetic nanoparticles. Temperature stability for all three phytases was enhanced as a consequence of immobilisation, whereas pH dependence of enzyme activity was not affected. Maximum catalytic activity of the immobilised phytases was found at 60°C (rye), 65°C (Aspergillus niger) and 70°C (Escherichia albertii). The immobilised enzymes exhibited the same excellent substrate specificities and unique myo-inositol phosphate phosphatase activities as their soluble counterparts. However, the catalytic turnover number dropped drastically for the immobilised phytases. The amount of the desired partially phosphorylated myo-inositol phosphate isomer could be easily controlled by the contact time of substrate solution and immobilised enzymes. The immobilised phytases showed a high operational stability by retaining almost full activity even after fifty uses.
KW - 6-Phytase
KW - Enzymes, Immobilized
KW - Hydrogen-Ion Concentration
KW - Hydrolysis
KW - Inositol Phosphates
KW - Kinetics
KW - Magnetics
KW - Nanoparticles
KW - Phosphorylation
KW - Substrate Specificity
KW - Temperature
U2 - 10.1016/j.biortech.2013.05.056
DO - 10.1016/j.biortech.2013.05.056
M3 - Journal article
C2 - 23747448
VL - 142
SP - 375
EP - 383
JO - Bioresource Technology
JF - Bioresource Technology
SN - 0960-8524
ER -