Enzymatic synthesis of alkyl glucosides using Leuconostoc mesenteroides dextransucrase

Abstract

Alkyl glucosides were synthesized by the reaction of Leuconostoc mesenteroides dextransucrase with sucrose and various alcohols. Alkyl alpha-D-glucosides were obtained with a yield of 30% (mol/mol) with primary alcohols, but secondary alcohols or tertiary alcohols gave yields below 5%. The optimal yield was 50% using 1-butyl alpha-D-glucoside with 0.9 M 1-butanol. The acceptor products of methanol or ethanol were confirmed as methyl alpha-D-glucopyranoside and ethyl alpha-D: -glucopyranoside via MALDI-TOF MS and NMR analysis. Thus, methyl or ethyl alpha-D-glucoside constituted half the emulsification activities of Triton X-100 as commercially available surfactants.

Characterization of Two α-Glucosidases Purified from Bifidobacterium longum subsp. longum JCM 7052

“…Production of ethyl-α-D-glucoside has been performed through alcohol fermentation with rice [29], and transglucosylation of enzymes. α-Glucosidase of Mortierella alliacea transfers glucose from starch to ethanol [30], while Leuconostoc mesenteroides dextransucrase uses sucrose to form ethyl-α-D-glucoside [31]. In this study we tested only palatinose as glucosyl donor in the synthesis of alkyl glucoside by the oligo-1,6glucosidases BlAglA1 and BlAglA2.…”

Maximization of dextransucrase activity expressed in E. coli by mutation and its functional characterization

“…DSRN showed higher acceptor reaction efficiency than DSRB742 with maltose. The acceptor reaction efficiency of DSRB742 with maltose was found to be similar to that of cellulose, with a 42% yield (Kim et al 1999). Among the DSRN mutants, DSRN3 and DSRN4 exhibited the highest and lowest acceptor reaction efficiencies, respectively, over the three acceptors.…”

“…Here, we describe novel genes, DSRN by ultrasoft x-ray exposure and its four mutants by site-directed mutagenesis. Dextransucrase enzymes from those mutants showed higher specific activity or enzymatic transglycosylation, compared to that of DSRB742 or of DSRB742CK, produced in previous studies (Kim et al 1999;Kang et al 2003). This paper describes the first comparative analysis of enzyme kinetics and catalytic efficiency (Kcat/Km) of DSRB742 and its mutants.…”

“…Dextransucrase activity was determined via analysis of the quantity of fructose released at 28°C from 200 mM sucrose in sodium acetate buffer (pH 5.2). The quantity of fructose was analyzed by TLC plates using a densitometer, as described previously by Kim et al (1999). One unit of dextransucrase was shown to release 1 lmol fructose from sucrose per min.…”

“…Park et al (2001) postulated that DSRB742 has a separate maltose-binding site from the sucrose-binding site, unlike the DSRS of Leuconostoc mesenteroides B512F. Kim et al (1999) reported that DSRB742 gene was isolated from Leuconostoc mesenteroides as an extracellular dextransucrase and expressed in E. coli. DSRB742 dextransucrase primarily synthesizes a-(1?6) linked-dextrans with 3-5% a-(1?3) branch linkages.…”