Section 37
Chapter 36,623

Cost effective surface functionalization of silver nanoparticles for high yield immobilization of Aspergillus oryzae ?-galactosidase and its application in lactose hydrolysis

Shakeel Ahmed Ansari; Rukhsana Satar; Fahad Alam; Mohammed Husein Alqahtani; Adeel Gulzar Chaudhary; Muhammad Imran Naseer; Sajjad Karim; Ishfaq Ahmed Sheikh

Process Biochemistry 47(12)


ISSN/ISBN: 1359-5113
DOI: 10.1016/j.procbio.2012.10.002
Accession: 036622189

Download citation:  

The present study demonstrates synthesis, characterization and surface functionalization of silver nanoparticles (AgNPs) via glutaraldehyde for high yield immobilization of Aspergillus oryzae ?-galactosidase. Soluble ?-galactosidase (S?G), enzyme adsorbed on unmodified AgNPs (U?G) and surface modified AgNPs (M?G) showed same pH-optima at pH 4.5. However, it was observed that M?G exhibited enhanced pH stability towards acidic and alkaline sides, and increased temperature resistance as compared to S?G and U?G. Michaelis constant, Km was increased nearly three-folds for M?G while Vmax for soluble and M?G was 0.515mM/min and 0.495mM/min, respectively. Furthermore, M?G showed greater resistance to product inhibition mediated by galactose as compared to it soluble counterpart and exhibited excellent catalytic activity even after its fourth successive reuse. The remarkable bioconversion rates of lactose from milk in batch reactors further revealed an attractive catalytic efficiency of ?-galactosidase adsorbed on surface functionalized AgNPs thereby promoting its use in the production of lactose free dairy products. AgNPs were synthesised, characterized and surface modified by glutaraldehyde. Aspergillus oryzae ? galactosidase was adsorbed on unmodified and modified AgNPs. Immobilized enzyme was used for hydrolyzing whey and milk lactose. Operational stability of immobilized ? galactosidase was also investigated.

PDF emailed within 0-6 h: $19.90