|Holt, Scott - WESTERN IL UNIV|
|Miller-Fosmore, Candace - WESTERN IL UNIV|
Submitted to: Carbohydrate International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: July 12, 2002
Publication Date: N/A
Technical Abstract: Glucansucrases synthesize alpha-D-glucans via glucosyl transfer from sucrose. The product of dextransucrase is predominantly an alpha-(1-6)-linked product, whereas alternansucrase synthesizes an alpha-(1-3),(1-6)-D-glucan with alternating linkages. Glucansucrases also catalyze acceptor reactions, resulting in the formation of various oligosaccharides. Alternansucrase has been found to be more efficient tha dextransucrase at carrying out acceptor reactions and synthesizes oligosaccharides containing a greater variety of linkages (Cote & Robyt, Carbohydr. Res. 111 (1982) 127-142). Whereas dextransucrase generally makes only a single product from any given acceptor, alternansucrase often makes two or more, and in higher yields. In addition, some sugars that are reported to be non-acceptors for dextransucrase are acceptors for alternansucrase. We have used alternansucrase to synthesize oligosaccharides from maltose, maltodextrins, maltitol, cellobiose, raffinose, melibiose, lactose, and numerous other acceptors. It was found that some acceptors are capable of increasing the rate of sucrase activity by as much as 3-fold. Several of these oligosaccharide acceptor products have been isolated and tested for their ability to support the growth of probiotic bacteria, including strains of Lactobacillus and Bifidobacterium. Certain acceptor products supported growth of probiotic strains, but did not serve as substrates for undesirable bacteria such as Salmonella, Clostridium, or E. coli. The structures of the acceptor products and their potential as prebiotics will be discussed.