title: Co-immobilized glucose oxidase and β-galactosidase on bovine serum albumin coated allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) copolymer as a biosensor for lactose determination in milk.
abstract: Bovine serum albumin (BSA) was adsorbed on allyl glycidyl ether (AGE)-ethylene glycol dimethacrylate (EGDM) copolymer with 25% crosslink density (AGE-25) at pH 8.0 (16% w/w). The amino, thiol and carboxylic acid functional groups available on protein coated surface were utilized for covalent immobilization of glucose oxidase and β-galactosidase, both independently, and in a step-wise manner on the same matrix, with no more than 10% loss of enzyme activity during immobilization. Glutaraldehyde cross-linking after immobilization provided stable enzyme preparations. The pH-optima of the immobilized enzymes were similar to those for free enzyme but their thermal stability was vastly improved. The co-immobilized enzyme support was used as a biosensor for determination of lactose in milk with excellent reproducibility and reusability.
authors.affiliation: Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500007, India.
authors.forename: Lakshmi Swarnalatha
authors.initials: LS
authors.lastname: Jasti
authors.affiliation: Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500007, India.
authors.forename: Sandhya Rani
authors.initials: SR
authors.lastname: Dola
authors.affiliation: Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500007, India. Electronic address: fadnavisnw@yahoo.com.
authors.forename: Nitin W
authors.initials: NW
authors.lastname: Fadnavis
authors.affiliation: Centre for Biotechnology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500085, India.
authors.forename: Uma
authors.initials: U
authors.lastname: Addepally
authors.affiliation: Polymer Science & Engineering, Chemical Engineering Division, National Chemical Laboratory, Pashan Road, Pune 411008, India.
authors.forename: Siona
authors.initials: S
authors.lastname: Daniels
authors.affiliation: Polymer Science & Engineering, Chemical Engineering Division, National Chemical Laboratory, Pashan Road, Pune 411008, India.
authors.forename: Surendra
authors.initials: S
authors.lastname: Ponrathnam
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D005949:Glucose Oxidase; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007700:Kinetics; D007785:Lactose / Q000032:analysis*; D008689:Methacrylates; D008892:Milk / Q000737:chemistry*; D012710:Serum Albumin, Bovine; D013696:Temperature; D001616:beta-Galactosidase
chemical_list: D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D007202:Indicators and Reagents; D008689:Methacrylates; D012710:Serum Albumin, Bovine; C004919:ethylene dimethacrylate; D005949:Glucose Oxidase; D001616:beta-Galactosidase; C054361:allyl glycidyl ether; D007785:Lactose
keywords: Bovine serum albumin; Glucose oxidase; Immobilization; Lactose assay; β-Galactosidase