Cell wall invertase immobilization within calcium alginate beads

• Published in: Food chemistry Vol. 104; no. 1; pp. 81 - 86
• Main Authors: Milovanovic, A, Bozic, N, Vujcic, Z
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2007; Elsevier
• Subjects: Alginate; alginates; bakers yeast; beta-fructofuranosidase; Biological and medical sciences; calcium; calcium alginate; cell wall components; Cell wall invertase; cell walls; enzyme inhibition; Food additives; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Immobilization; immobilized enzymes; Saccharomyces cerevisiae; Immobilization; Alginate; Saccharomyces cerevisiae; Cell wall invertase; Yeast; Calcium; Enzyme; β-Fructofuranosidase; Food additive; Alginates; Inorganic element; Cell wall; Fungi; Gelling agent; Glycosidases; Hydrolases; Ascomycetes; O-Glycosidases; Thallophyta
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2006.11.001

Yeast cell wall invertase (CWI) was immobilized within calcium alginate beads. The result of entrapment was the complete immobilization of all the added CWI. Three types of biocatalysts were prepared: CWI-S, CWI-155 and CWI-157. The optimum pH values were 4.5 and 5.0 for free and immobilized invertase, respectively. The optimum temperature was 60 °C, for both free CWI and CWI-S immobilizate. 80 °C was the optimum temperature for CWI-155 whereas the optimum temperature for CWI-157 ranged from 50 °C to 80 °C. Immobilized CWI was more stable than was free CWI above optimum activity temperatures. The activation energies were 32 kJ/mol for free CWI and 45, 21 and 25 kJ/mol for CWI-S, CWI-155 and CWI-157, respectively. The K m values of free and immobilized CWI-157 were 28.4 mM and 72 mM, respectively. The V max values were estimated as 4.5 mM/min and 0.42 mM/min, respectively. Immobilized CWI-157 was tested in a batch reactor using 70% sucrose (w/v). Complete sucrose conversion was achieved after 55 h. After 40 consecutive cycles, CWI-157 retained 90% of its activity.