Immobilization of glucose isomerase in surface-modified alginate gel beads

TÜMTÜRK H., DEMİREL G., ALTINOK H., AKSOY S., Hasirci N.

JOURNAL OF FOOD BIOCHEMISTRY, cilt.32, sa.2, ss.234-246, 2008 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 32 Sayı: 2
  • Basım Tarihi: 2008
  • Doi Numarası: 10.1111/j.1745-4514.2008.00171.x
  • Dergi Adı: JOURNAL OF FOOD BIOCHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.234-246
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

In this study, glucose isomerase enzyme was entrapped into modified and nonmodified calcium alginate gel beads. Various characteristics of free and immobilized enzymes such as the optimum pH, temperature and dependence of activity on storage and operational stability were evaluated. The optimum pH and temperature of free and immobilized glucose isomerase were found to be the same values as 7.5 and 60C, respectively. For free and immobilized enzymes, kinetic parameters were calculated as 1.79 x 10(-2) and 8.27 x 10(-3) mol/L for Km, and 2.39 x 10(-3) and 6.03 x 10(-3) mol/L min for V-max, respectively. After 42 days of storage at 4C, free enzyme retained 56% of its initial activity, while for the immobilized enzyme, this value was observed as 86%. The immobilized samples were used repeatedly 22 times by retaining more than 85% of their initial activity.