title: Kinetic studies and model development for the formation of galacto-oligosaccharides from lactose using synthesized thermo-responsive bioconjugate.
abstract: In an earlier study by us [47], thermo-responsive bioconjugate (poly-N-isopropylacrylamide-β-galactosidase) was synthesized and characterized. This study utilizes the prowess of such smart bioconjugate for the enzymatic synthesis of galacto-oligosaccharides (GOS) from lactose at various initial lactose concentrations (ILC), enzyme concentrations, and temperatures, while maintaining a constant pH of 6. A maximum GOS yield of 35% (on dry basis) was observed at 100g/L ILC and 0.275mg/mL (0.055U/mL) conjugated protein. The GOS yield remained approximately the same for 50 and 100g/L ILC, beyond which, it decreased. As the enzyme concentration increased, the equilibrium formation of GOS increased and eventually attained a plateau when the concentration of conjugated protein exceeded 0.275mg/mL (0.055U/mL). GOS yield increased on raising the temperature from 30 to 40°C, and declined thereafter. The apparent kinetic parameters were estimated from a five-step, nine-parameter kinetic model, which was then simulated using the COPASI package. The simulated results demonstrated an excellent match with the experimental data.
authors: Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
authors: Tapas
authors: T
authors: Palai
authors: Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208016, India. Electronic address: ashokkum@iitk.ac.in.
authors: Ashok
authors: A
authors: Kumar
authors: Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India. Electronic address: pkbhatta@iitk.ac.in.
authors: Prashant K
authors: PK
authors: Bhattacharya
mesh_terms: D000180:Acrylic Resins / Q000378:metabolism; D001407:Bacillus / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001709:Biotechnology; D004795:Enzyme Stability; D005690:Galactose / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D007785:Lactose / Q000378:metabolism*; D008954:Models, Biological; D009844:Oligosaccharides / Q000096:biosynthesis* / Q000737:chemistry; D013696:Temperature; D001616:beta-Galactosidase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000180:Acrylic Resins; D001426:Bacterial Proteins; D009844:Oligosaccharides; C052970:poly-N-isopropylacrylamide; D001616:beta-Galactosidase; D007785:Lactose; D005690:Galactose
keywords: Enzyme immobilization; Galacto-oligosaccharide; Kinetic model; Lactose; Poly-N-isopropyl acrylamide; Responsive bioconjugate