Synthesis of methyl alpha-D-glucooligosaccharides by entrapped dextransucrase from Leuconostoc mesenteroides B-1299.
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.
de Segura
Aránzazu Gómez
AG
Departamento de Biocatálisis, Instituto de Catálisis y Petroleoquímica, CSIC, Cantoblanco, Madrid, Spain.
Alcalde
Miguel
M
Bernabé
Manuel
M
Ballesteros
Antonio
A
Plou
Francisco J
FJ
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
D004187:Disaccharides; D004800:Enzymes, Immobilized; D008757:Methylglucosides; D013549:Sweetening Agents; D005964:Glucosyltransferases; C020025:dextransucrase; C060525:leucrose