title: Synthesis of methyl alpha-D-glucooligosaccharides by entrapped dextransucrase from Leuconostoc mesenteroides B-1299.
abstract: The synthesis of methyl alpha-D-glucooligosaccharides, using sucrose as glucosyl donor and methyl alpha-D-glucopyranoside as acceptor, was studied with dextransucrase from Leuconostoc mesenteroides NRRL B-1299. The enzyme was immobilized by entrapment in alginate. By NMR and mass spectrometry we identified three homologous series (S1-S3) of methyl alpha-D-glucooligosaccharides. Series S2 and S3 were characterized by the presence of alpha(1-->2) linkages, in combination with alpha(1-->6) bonds. Two parameters, sucrose to acceptor concentration ratio (S/A) and the total sugar concentration (TSC) determined the yield of methyl alpha-D-glucooligosaccharides. The maximum concentration achieved of the first acceptor product, methyl alpha-D-isomaltoside, was 65 mM using a S/A 1:4 and a TSC of 336 g l(-1). When increasing temperature, a shift of selectivity towards compounds containing alpha(1-->2) bonds was observed. The formation of leucrose as a side process was very significant (reaching values of 32 g l(-1)) at high sucrose concentrations.
authors.affiliation: Departamento de Biocatálisis, Instituto de Catálisis y Petroleoquímica, CSIC, Cantoblanco, Madrid, Spain.
authors.forename: Aránzazu Gómez
authors.initials: AG
authors.lastname: de Segura
authors.forename: Miguel
authors.initials: M
authors.lastname: Alcalde
authors.forename: Manuel
authors.initials: M
authors.lastname: Bernabé
authors.forename: Antonio
authors.initials: A
authors.lastname: Ballesteros
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Plou
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004187:Disaccharides / Q000096:biosynthesis*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005964:Glucosyltransferases / Q000737:chemistry; D007218:Industrial Microbiology / Q000379:methods*; D007934:Leuconostoc / Q000201:enzymology*; D009682:Magnetic Resonance Spectroscopy; D008757:Methylglucosides / Q000096:biosynthesis*; D013549:Sweetening Agents
chemical_list: D004187:Disaccharides; D004800:Enzymes, Immobilized; D008757:Methylglucosides; D013549:Sweetening Agents; D005964:Glucosyltransferases; C020025:dextransucrase; C060525:leucrose