Activity, stability, and binding capacity of β-galactosidase immobilized on electrospun nylon-6 fiber membrane
| Autor: | Jason Kenealey, D.A. Hutchins, J. Noh |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Immobilized enzyme
Polymers Lactose 03 medical and health sciences chemistry.chemical_compound Genetics Animals Caprolactam Fiber 030304 developmental biology 0303 health sciences Chromatography biology Chemistry Hydrolysis Temperature 0402 animal and dairy science Substrate (chemistry) 04 agricultural and veterinary sciences Hydrogen-Ion Concentration Enzymes Immobilized beta-Galactosidase 040201 dairy & animal science Polyvinylidene fluoride Enzyme assay Enzyme binding Membrane biology.protein Animal Science and Zoology Food Science |
| Zdroj: | Journal of Dairy Science. 104:3888-3898 |
| ISSN: | 0022-0302 |
| DOI: | 10.3168/jds.2020-19453 |
| Popis: | In this research, we explored various immobilized enzyme support materials, including the novel nylon-6 fiber membrane (NFM), and evaluated the increase in surface area and its effect on enzyme binding potential. We also manipulated incubation and reaction conditions and assessed the subsequent effects on activity and stability of β-galactosidase, with comparisons between various solid support materials and free (dissolved) enzyme. Nylon-6 fiber membranes were created by electrospinning and were compared with other materials as solid supports for enzyme binding. The other materials included polyvinylidene fluoride 5-kDa nanofiltration dairy membranes, nylon-6 pellets, and silica glass beads. Scanning electron microscopy revealed the large surface area of NFM, which correlated with greater enzyme activity compared with the relatively flatter surfaces of the other solid support materials. Enzyme activity was measured spectrophotometrically with the color-changing substrate o-nitrophenyl-β-d-galactopyranoside. Compared with the other solid supports, NFM had greater maximum enzyme binding potential. Across pH conditions ranging from 3.5 to 6.0 (including the optimal pH of 4.0-5.0), enzyme activity was maintained on the membrane-immobilized samples, whereas free enzyme did not maintain activity. Altering the storage temperature (4, 22, and 50°C) affected enzyme stability (i.e., the ability of the enzyme to maintain activity over time) of free and polyvinylidene fluoride membrane samples. However, NFM samples maintained stability across the varying storage temperatures. Increasing the immobilization solution enzyme concentration above the maximum enzyme binding capacity had no significant effect on enzyme stability for membrane-immobilized samples; however, both had lower mean stability than free enzyme by approximately 74%. With further development, β-galactosidase immobilized on NFM or other membranes could be used in continuous processing in the dairy industry for a combination of filtration and lactose hydrolysis-creating products that are reduced in lactose and increased in sweetness, with no requirement for "added sugars" on the nutrition label and no enzyme listed as final product ingredient. |
| Databáze: | OpenAIRE |
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