Abstract
Recombinant Bacillus subtilis lipase was immobilised on magnetic nanoparticles by a facile covalent method and applied to fish oil hydrolysis. High loading of enzyme to the functionalised nanoparticle was achieved with a protein binding efficiency of 95%. Structural changes of the confined enzyme on the surface of the nanoparticles was investigated using transmission electron microscopy and spectroscopic techniques (attenuated total reflectance-Fourier transform infrared and circular dichroism). The biocatalytic potential of immobilised lipase was compared with that of free enzyme and biochemically characterised with respect to different parameters such as pH, temperature, substrate concentrations and substrate specificity. The thermal stability of functionalised nanoparticle bound enzyme was doubled that of free enzyme. Immobilised lipase retained more than 50% of its initial biocatalytic activity after recyclability for twenty cycles. The ability to the immobilised thermostable lipase to concentrate omega-3 fatty acids from fish oil was investigated. Using synthetic substrate, the immobilised enzyme showed 1.5 times higher selectivity for docosahexaenoic acid (DHA), and retained the same degree of selectivity for eicosapentaenoic acid (EPA), when compared to the free enzyme.
| Original language | English |
|---|---|
| Article number | 420 |
| Number of pages | 15 |
| Journal | Catalysts |
| Volume | 9 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 2019 |
Bibliographical note
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedKeywords
- Covalent immobilisation
- Fish oil
- Magnetic
- Omega-3 fatty acids
- Recombinant enzyme
- Structure characterisation