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E. H. Melvin

Bio: E. H. Melvin is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 428 citations.

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Journal ArticleDOI
TL;DR: 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.
Abstract: 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 dextran with the dextran dextrinase enzyme. Emphasis is mainly focused on Leuconostoc strains as producer organisms of dextransucrase and dextran types. In addition to industrial fermentation processes producing the enzymes and/or the dextrans, biocatalysis principles are also being developed, whereby enzyme preparations convert sucrose or maltodextrins, respectively, into (oligo)dextrans. The chemical and physical properties of different dextrans are discussed in detail, together with the characteristics and molecular mode of action of dextransucrase. Subsequently, useful applications of dextran and some problems associated with undesirable formation of dextran are outlined. Copyright © 2005 Society of Chemical Industry

389 citations

Journal ArticleDOI
TL;DR: The precipitin reaction between concanavalin A, a globulin isolated from jackbean meal, and certain polysaccharides has been examined and the reaction appears to be analogous to an antibody-antigen system.

334 citations

Journal ArticleDOI
TL;DR: The enzymatic synthesis of fructans (levan and inulin) is poorly documented at the molecular level, but the field of Streptococcus and Leuconostoc glucansucrases (glucosyltransferases and dextransucrase) has been well studied, both at the mechanistic and gene structure levels.

315 citations

Book ChapterDOI
TL;DR: In this paper, the carbon-13 NMR spectra of polysaccharides with mixed linkages have been examined and a series of α-and β-shifts have been determined for mono-O -methylglucoses and mono- O -methylmannoses to aid in the assignments of 13 C signals of oligosaccharides and poly-scharides consisting of glucose and mannose respectively.
Abstract: Publisher Summary This chapter examines the carbon-13 nuclear magnetic resonance spectroscopy of polysaccharides. The C-1 resonances of the pyranoid forms of glucose, xylose, galactose, arabinose, methyl glucoside, and methyl xyloside are shown to be sensitive to the anomeric configuration. The C-1 chemical-shifts of furanosides are generally at lower field than those of their anomeric counterparts in the pyranose series. The values of a series of α- and β-shifts have been determined for mono- O -methylglucoses and mono- O -methylmannoses to aid in the assignments of 13 C signals of oligosaccharides and polysaccharides consisting of glucose and mannose respectively. The 13 C-NMR spectra of polysaccharides having mixed linkages can sometimes be interpreted by the reference to the spectra of homopolymers representing each type of linkage. The C-2 to C-6 signals of monorhamnomannan were rationalized by gauging substitution-shifts and by the use of D -glucose precursors labeled with 2 H or 13 C. Glucose gave a rhamnomannan whose spectrum lacked the signal at 66.7, characterizing it as from C-6. The polysaccharides containing 3-deoxy- D -manno-octulosylonic acid residues are also elaborated.

288 citations