title: Kinetics of lactose conversion to galacto-oligosaccharides by β-galactosidase immobilized on PVDF membrane.
abstract: Experimental studies were made for immobilization of enzymes on microporous polyvinylidene fluoride (PVDF) membrane in order to carry out enzymatic reaction of lactose into galacto-oligosaccharides using β-galactosidase. The present work, however, is the first part in the direction of enzymatic membrane reactor studies for carrying out reaction followed by membrane based separation to purify galacto-oligosaccharides out of reaction mixture. The middle of the three compartment cell, separated by two immobilized (enzyme) membranes, was utilized to feed lactose solution; whereas, adjacent compartments were filled with distilled water. The reacted mixture solution was analyzed for tri-, tetra- and penta-forms of GOS. The formation of product GOS strongly depended on varying amounts of initial lactose concentration (ILC). Total GOS formation increased from 7% to 28% for ILC from 50 to 200 g/L. However, tri-saccharide was the major (67%) in comparison to tetra (27%) and penta (6%) forms of GOS. Further, based on Michaelis-Menten kinetics, a six-step-eleven-parameter model was developed. The model incorporated enzyme inhibition and formation of glucose and galactose separately. Simulated results from developed model matched exceeding well with experimental results.
authors: Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
authors: Tapas
authors: T
authors: Palai
authors: Prashant K
authors: PK
authors: Bhattacharya
mesh_terms: D004800:Enzymes, Immobilized / Q000378:metabolism*; D005690:Galactose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D007785:Lactose / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D011145:Polyvinyls / Q000737:chemistry*; D001616:beta-Galactosidase / Q000378:metabolism*; D005465:Fluorocarbon Polymers
chemical_list: D004800:Enzymes, Immobilized; D005690:Galactose; D005947:Glucose; D007785:Lactose; D009844:Oligosaccharides; D011145:Polyvinyls; D001616:beta-Galactosidase; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers