Glucose oxidase immobilization on a novel cellulose acetate-polymethylmethacrylate membrane.
Glucose oxidase (GOD) was immobilized on cellulose acetate-polymethylmethacrylate (CA-PMMA) membrane. The immobilized GOD showed better performance as compared to the free enzyme in terms of thermal stability retaining 46% of the original activity at 70 degrees C where the original activity corresponded to that obtained at 20 degrees C. FT-IR and SEM were employed to study the membrane morphology and structure after treatment at 70 degrees C. The pH profile of the immobilized and the free enzyme was found to be similar. A 2.4-fold increase in Km value was observed after immobilization whereas Vmax value was lower for the immobilized GOD. Immobilized glucose oxidase showed improved operational stability by maintaining 33% of the initial activity after 35 cycles of repeated use and was found to retain 94% of activity after 1 month storage period. Improved resistance against urea denaturation was achieved and the immobilized glucose oxidase retained 50% of the activity without urea in the presence of 5M urea whereas free enzyme retained only 8% activity.
Rauf
S
S
Bioprocess Technology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O. Box 577, Jhang Road, Faisalabad, Pakistan.
Ihsan
A
A
Akhtar
K
K
Ghauri
M A
MA
Rahman
M
M
Anwar
M A
MA
Khalid
A M
AM
D015374:Biosensing Techniques; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry / Q000648:ultrastructure; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism* / Q000648:ultrastructure; D005949:Glucose Oxidase / Q000032:analysis / Q000378:metabolism* / Q000648:ultrastructure; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014508:Urea / Q000494:pharmacology
D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; C005062:acetylcellulose; D014508:Urea; D002482:Cellulose; D019904:Polymethyl Methacrylate; D005949:Glucose Oxidase