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Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work we review the extraordinary biotechnological potential of two glycosyltransferases, cyclodextrin glucanotransferase and dextransucrase, especially their utility in the synthesis of oligosaccharides. Both enzymes are non-Leloir transferases that require neither co-factors nor activated substrates, as they directly employ the free energy of cleavage of starch and sucrose, respectively. Cyclodextrin glucanotransferase is able to produce cyclodextrins from starch. In the presence of appropriate acceptors (e.g., carbohydrates), this enzyme furnishes oligosaccharides containing α(14) bonds. Thus, we have found that glucose, maltose, and sucrose readily serve as acceptors to form the corresponding [Glc-α(14)][sub n] - oligosaccharides, with the degree of polymerization being controlled by the starch:acceptor ratio. The ability of other sugars and related compounds to act as acceptors is also reviewed. Dextransucrase is a glycansucrase that synthesizes dextran using sucrose as glucosyl donor. The formation of dextrans can be quantitatively replaced with the formation of novel oligosaccharides by adding alternative carbohydrate acceptors to the reaction medium. With the dextransucrase from Leuconostoc mesenteroides B-1299, we have investigated the synthesis of gluco- oligosaccharides containing α(12) bonds using methyl 1-O-α-D-glucopyranoside as the acceptor. These products constitute a class of nondigestible nutraceutical oligosaccharides with prebiotic properties relating to the stabilization and enhancement of gastrointestinal tract flora, and are being increasingly used by the food industry.Key words: glycansucrases, cyclodextrin glucanotransferase, cyclodextrin glucosyltransferase, dextransucrase, acceptor products, gluco-oligosaccharides, malto-oligosaccharides, coupling sugar, nutraceuticals, functional foods, prebiotics.Dans ce travail, on passe en revue le potentiel biotechnologique extraordinaire de deux glycosyltransférases, la glucanotransférase de la cyclodextrine et de la sucrase de dextrane, en particulier de leurs utilités dans la synthèse d'oligosaccharides. Les deux enzymes sont des transférases non Lenoir qui ne nécessitent pas de cofacteurs ou de substrats activés puisqu'ils utilisent directement l'énergie libre de clivage de l'amidon et du sucrose respectivement. La glucanotransférase de la cyclodextrine peut produire des cyclodextrines à partir de l'amidon. En présence d'accepteurs appropriés (par exemple des carbohydrates), cet enzyme conduit à la formation d'oligosaccharides contenant des liaisons α(14). On a ainsi observé que le glucose, le maltose et le sucrose peuvent facilement servir d'accepteurs pour former les oligosaccharides [Glc-α(14)][sub n] - correspondants dans lesquels le degré de polymérisation est déterminé par le rapport amidon/accepteur. On a aussi passé en revue la possibilité d'autres sucres et de composés apparentés à agir comme accepteurs. La sucrase du dextrane est une sucrase de glycane qui synthétise du dextrane à partir du sucrose agissant comme donneur de glycosyle. La formation des dextranes peut être remplacée quantitativement par la formation de nouveaux oligosaccharides par l'addition de carbohydrates accepteurs dans le milieu réactionnel. Avec la sucrase de dextrane provenant du Leuconostos mesentoroides B-1299, nous avons étudié la synthèse de glucooligosaccharides contenant des liaisons α(12) en faisant appel au 1-O-α-D-glucopyranoside de méthyle comme accepteur. Ces produits constituent une classe d'oligosaccharides nutraceutiques non digestibles possédant des propriétés prébiotiques découlant d'une stabilisation et d'une augmentation de la flore intestinale et qui sont de plus en plus utilisés dans l'industrie alimentaire.Mots clés : sucrases de glycane, cyclodextrine, glucanotransférase, glucosyltransférase de la cyclodextrine, sucrase de dextrane, produits accepteurs, glucooligosaccharides, maltooligosaccharides, sucre qui se couple, nutraceutique, aliments fonctionnels, prébiotique.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]