Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers
Lactose has been hydrolyzed using covalently immobilized ß-galactosidase on thermally stable carrageenan coated with chitosan (hydrogel). The hydrogel's mode of interaction was proven by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and Schiff's base for...
| Main Authors: | , |
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| Format: | Journal Article |
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Humana Press, Inc.
2009
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| Online Access: | http://hdl.handle.net/20.500.11937/2891 |
| _version_ | 1848744077574537216 |
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| author | Elnashar, Magdy Yassin, M. |
| author_facet | Elnashar, Magdy Yassin, M. |
| author_sort | Elnashar, Magdy |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Lactose has been hydrolyzed using covalently immobilized ß-galactosidase on thermally stable carrageenan coated with chitosan (hydrogel). The hydrogel's mode of interaction was proven by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and Schiff's base formation. The DSC thermogram proved the formation of a strong polyelectrolyte complex between carrageenan and chitosan followed by glutaraldehyde as they formed one single peak. The modification of carrageenan improved the gel's thermal stability in solutions from 35 °C to 95 °C. The hydrogel has been proven to be efficient for ß-galactosidase immobilization where 11 U/g wet gel was immobilized with 50% enzyme loading capacity. Activity and stability of free and immobilized ß-galactosidase towards pH and temperature showed marked shifts in their optimum pH from 4.5-5 to 5-5.5 and temperature from 50 °C to 45-55 °C after immobilization, which reveals higher catalytic activity and reasonable stability at wider pHs and temperatures. The apparent K m of the immobilized enzyme increased from 13.2 to 125 mM, whereas the V max increased from 3.2 to 6.6 µmol/min compared to the free enzyme, respectively. The free and immobilized enzymes showed lactose conversion of 87% and 70% at 7 h, respectively. The operational stability showed 97% retention of the enzyme activity after 15 uses, which demonstrates that the covalently immobilized enzyme is unlikely to leach. The new carrier could be suitable for immobilization of other industrial enzymes. © 2008 Humana Press Inc. |
| first_indexed | 2025-11-14T05:55:44Z |
| format | Journal Article |
| id | curtin-20.500.11937-2891 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T05:55:44Z |
| publishDate | 2009 |
| publisher | Humana Press, Inc. |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-28912017-09-13T14:30:54Z Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers Elnashar, Magdy Yassin, M. Lactose has been hydrolyzed using covalently immobilized ß-galactosidase on thermally stable carrageenan coated with chitosan (hydrogel). The hydrogel's mode of interaction was proven by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and Schiff's base formation. The DSC thermogram proved the formation of a strong polyelectrolyte complex between carrageenan and chitosan followed by glutaraldehyde as they formed one single peak. The modification of carrageenan improved the gel's thermal stability in solutions from 35 °C to 95 °C. The hydrogel has been proven to be efficient for ß-galactosidase immobilization where 11 U/g wet gel was immobilized with 50% enzyme loading capacity. Activity and stability of free and immobilized ß-galactosidase towards pH and temperature showed marked shifts in their optimum pH from 4.5-5 to 5-5.5 and temperature from 50 °C to 45-55 °C after immobilization, which reveals higher catalytic activity and reasonable stability at wider pHs and temperatures. The apparent K m of the immobilized enzyme increased from 13.2 to 125 mM, whereas the V max increased from 3.2 to 6.6 µmol/min compared to the free enzyme, respectively. The free and immobilized enzymes showed lactose conversion of 87% and 70% at 7 h, respectively. The operational stability showed 97% retention of the enzyme activity after 15 uses, which demonstrates that the covalently immobilized enzyme is unlikely to leach. The new carrier could be suitable for immobilization of other industrial enzymes. © 2008 Humana Press Inc. 2009 Journal Article http://hdl.handle.net/20.500.11937/2891 10.1007/s12010-008-8453-3 Humana Press, Inc. restricted |
| spellingShingle | Elnashar, Magdy Yassin, M. Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers |
| title | Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers |
| title_full | Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers |
| title_fullStr | Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers |
| title_full_unstemmed | Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers |
| title_short | Lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers |
| title_sort | lactose hydrolysis by ß-galactosidase covalently immobilized to thermally stable biopolymers |
| url | http://hdl.handle.net/20.500.11937/2891 |