Immobilisation of β-galactosidase onto double layered hydrophilic polymer coated magnetic nanoparticles: Preparation, characterisation and lactose hydrolysis

BAYRAMOĞLU G., Cimen A. G., ARICA M.

International Dairy Journal, cilt.138, 2023 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 138
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1016/j.idairyj.2022.105545
  • Dergi Adı: International Dairy Journal
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Food Science & Technology Abstracts, Veterinary Science Database
  • Gazi Üniversitesi Adresli: Evet

Özet

© 2022 Elsevier LtdThe surface of polydopamine (PDA) coated magnetic particles was grafted spontaneously with diaminopolyethylene glycol (DAPEG) as a second polymer layer by conjugation of PDA with DAPEG without using any activating agent. The amount of immobilised β-galactosidase was found to be 49.7 mg g−1 support. The optimum pH for the free and immobilised enzyme was observed at 5.5 and 6.0, respectively. The optimal temperature for the immobilised β-galactosidase was 15 °C higher compared with the free counterpart. The apparent Km values for the free and immobilised enzymes were found to be 3.69 and 4.35 mmol L−1, with Vmax values of 7.72 and 5.54 U mg−1, respectively. Thermal stability of β-galactosidase was increased upon immobilisation. Finally, the operational stability of the immobilised β-galactosidase was studied for lactose hydrolysis in a continuous reactor. After 96 h continuous operation, the remaining activity of the immobilised enzyme was 94%.