title: Microwave-assisted synthesis of galacto-oligosaccharides from lactose with immobilized beta-galactosidase from Kluyveromyces lactis.
abstract: Galacto-oligosaccharides (GOS) were synthesized from lactose by immobilized and free beta-galactosidase from Kluyveromyces lactis (Lactozym 3000 L HP-G) using either focused microwave irradiation or conventional heating. Immobilization of the beta-galactosidase on to Duolite A-568 increased the synthesis of GOS. GOS selectivity (GOS synthesis/lactose hydrolysis ratio) increased when the water activity of the media was reduced, notably with a high initial lactose concentration but also by using co-solvents in the media. The advantage of microwave heating on GOS formation was also examined. Addition of solvent and carrying out the reaction under microwave irradiation resulted an increase in the production of GOS. The selectivity for GOS synthesis can be increased by 217-fold under microwave irradiation, using immobilized beta-glucosidase and with added co-solvents such as hexanol.
authors.affiliation: Laboratoire de Génie Protéique et Cellulaire, EA3169, UFR Sciences Fondamentales et Sciences pour l'Ingénieur, Bâtiment Marie Curie, Université de La Rochelle, 17042 La Rochelle, France. tmaugard@univ-lr.fr
authors.forename: Thierry
authors.initials: T
authors.lastname: Maugard
authors.forename: Damian
authors.initials: D
authors.lastname: Gaunt
authors.forename: Marie Dominique
authors.initials: MD
authors.lastname: Legoy
authors.forename: Thierry
authors.initials: T
authors.lastname: Besson
mesh_terms: D004800:Enzymes, Immobilized; D005240:Feasibility Studies; D006358:Hot Temperature; D007716:Kluyveromyces / Q000145:classification / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects*; D007785:Lactose / Q000378:metabolism*; D008872:Microwaves; D009844:Oligosaccharides / Q000096:biosynthesis*; D012680:Sensitivity and Specificity; D012997:Solvents / Q000494:pharmacology; D013045:Species Specificity; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D009844:Oligosaccharides; D012997:Solvents; D001616:beta-Galactosidase; D007785:Lactose