B-galactosidase of kluyveromyces lactis: Immobilization, characterization and hydrolysis behavior of enzyme
by
Çabuk, Burcu.
Title
:
B-galactosidase of kluyveromyces lactis: Immobilization, characterization and hydrolysis behavior of enzyme
Author
:
Çabuk, Burcu.
Personal Author
:
Çabuk, Burcu.
Publication Information
:
[s.l.]: [s.n.], 2008
Physical Description
:
xiii, 75 106 leaves.: ill. + 1 computer laser optical disc.
Abstract
:
B-galactosidase (lactase) enzyme is of great industrial interest, since it can be used to solve problems associated with whey disposal and lactose crystallization in sweetened and frozen dairy products such as ice cream. All over the world, many people suffer from lactose intolerance and lactase preparations are used as supplements for these persons. B-galactosidase is also used to produce prebiotics since this enzyme hydrolyses lactose into galactooligosaccharides. Immobilized B-galactosidase preparations are preferred in many processes because they can be recycled and maintain their activities for a long time without loosing their chemical stability.Novel cross-linked chitosan-hydroxyapatite composite support has beenprepared, lactase from Kluyveromyces lactis was immobilized onto these beads. Lactase immobilization mechanism and effect of factors such as initial glutaraldehyde concentration, temperature, pH, initial lactase concentration, solid-liquid ratio on immobilzation mechanism were studied.Optimum cross-linking was obtained at the glutaraldehyde concentration of 100 mg/L. The optimum values of temperature, pH and solid/liquid ratio on lactase/HAChitosan were found to be 200C, pH 7.5 and 0.3g/ml Vg/Vl, respectively. The pH and thermal stabilities of free and immobilized enzymes were also investigated and it was observed that the relative activity remained above 83.2% within pH 6-7.5 and maximum activity yield was obtained at 370C for free and all immobilized enzymes. The Michaelis constant Km and Vmax of immobilized and free enzyme on chitosanhydroxyapatite composite beads were found to be 9.5 mM and Vm 454.5 .mol ONP min.1 mg.1 protein and 1.011 mM and 1098.9 .mol ONP min.1 mg.1 protein, respectively.
Subject Term
:
Beta-galactosidase.
Lactose.
Lactose intolerance.
Immobilized enzymes.
Hydrolysis.
Added Author
:
Harsa Şebnem.
Added Corporate Author
:
Izmir Institute of Technology. Food Engineering.
Added Uniform Title
:
Thesis (Master)--İzmir Institute of Technology:Food Engineering.
İzmir Institute of Technology:Food Engineering--Thesis (Master).
Electronic Access
:
Library | Material Type | Item Barcode | Shelf Number | Status |
---|
IYTE Library | Thesis | T000679 | QP609.63 C11 2008 | Tez Koleksiyonu |
IYTE Library | Supplementary CD-ROM | ROM1064 | QP609.63 C11 2008 EK1 | Tez Koleksiyonu |