14 INTRODUCTION 16 MATERIALS AND METHODS 19 Carbohydrates and reagents 19 Enzyme 19 Enzyme digest conditions 20 Digest conditions to obtain Hanes-Woolf plots 20 Digest conditions to obtain Michaelis plots 20 Determination of the amount of dextran synthesized 21 RESULTS AND DISCUSSION 22 REFERENCES 3 0 iii PAPER II INTERPRETATION OF DEXTRANSUCRASE INHIBITION AT HIGH SUCROSE CONCENTRATIONS 3 9 AB...

When an unstable enzyme is incubated with its substrate(s), catalysis may cease before chemical equilibrium is attained. The residual substrate concentrations depend on their initial concentrations, the initial enzymic activity, and the inactivation rate constants for each molecular species that comprise the catalytic cycle. The underlying theory has been elaborated previously for single-substr...

The gene coding for inulosucrase in Leuconostoc citreum CW28, islA, was cloned, sequenced, and expressed in Escherichia coli. The recombinant enzyme catalyzed inulin synthesis from sucrose like the wild-type enzyme. Inulosucrase presents an unusual structure: its N-terminal region is similar to the variable region of glucosyltransferases, its catalytic domain is similar to fructosyltransferases...

Glucose fermentation by lactic acid bacteria occurs by at least two different routes. Homolactic species, the streptococci and homolactobacilli, convert hexoses to lactate by the EmbdenMeyerhof pathway. Although the demonstration of glycolytic enzymes and the formation and degradation of glycolytic intermediates by cellfree preparations is incomplete, the conversion of glucose-3,4-C'4 to carbox...

Previous studies using traditional biochemical identification methods to study the ecology of commercial sauerkraut fermentations revealed that four species of lactic acid bacteria, Leuconostoc mesenteroides, Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus brevis, were the primary microorganisms in these fermentations. In this study, 686 isolates were collected from four com...

A sucrose phosphorylase (SPase) gene derived from Leuconostoc mesenteroides was introduced into a cellulose-producing Acetobacter strain and expressed under the lac promoter. The activity of the SPase was detected in extracts of the transformed cells and cellulose production from sucrose by the cells was found to have increased, which strongly suggests that the increase was the result of the ne...

This review covers the production, properties and applications of the biopolysaccharide dextran; this biopolymer can be produced via fermentation either with Leuconostoc mesenteroides strains and other lactic acid bacteria or with certain Gluconobacter oxydans strains. The former strains convert sucrose into dextran with the dextransucrase enzyme whereas the latter convert maltodextrins into de...