title: Synthesis of novel fructooligosaccharides by substrate and enzyme engineering.
abstract: Fructooligosaccharides (FOSs) and polyfructosides (PSs) have received particular attention due to its beneficial effects as prebiotics. Here we report the synthesis of a new class of fructooligosaccharides by substrate and enzyme engineering. Using an engineered levansucrase enzyme (SacB of Bacillus subtilis), and sucrose analogues (alpha-Xyl-1,2-beta-Fru or alpha-Gal-1,2-beta-Fru), the product profile shifted from the fructan (levan) polymer to a range of new higher oligosaccharides (xylooligofructosides), or polysaccharides (galactopolyfructosides), of varying size. Further the enzyme was tailored by random mutagenesis, for the synthesis of short-chain fructooligosaccharides to yield variant A5 (N242H), which is unable to produce polymers. It shifts its product pattern to short-chain oligosaccharides and hydrolysis and enabled in combination with the sucrose analogue Xyl-Fru for the first time the direct synthesis of a 6-kestose analogue (alpha-Xyl-1,2-beta-Fru-2,6-beta-Fru). The different glycopyranosyl-residues (i.e. galactose and xylose) that cap fructooligosaccharides may alter prebiotic and biochemical properties.
authors.affiliation: Department for Carbohydrate Technology, Technical University of Braunschweig, Hans-Sommer Str. 10, 38106 Braunschweig, Germany.
authors.forename: Rafael
authors.initials: R
authors.lastname: Beine
authors.forename: Roxana
authors.initials: R
authors.lastname: Moraru
authors.forename: Manfred
authors.initials: M
authors.lastname: Nimtz
authors.forename: Shukrallah
authors.initials: S
authors.lastname: Na'amnieh
authors.forename: Alice
authors.initials: A
authors.lastname: Pawlowski
authors.forename: Klaus
authors.initials: K
authors.lastname: Buchholz
authors.forename: Jürgen
authors.initials: J
authors.lastname: Seibel
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005818:Genetic Engineering / Q000379:methods*; D006602:Hexosyltransferases / Q000235:genetics / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D009844:Oligosaccharides; C116580:fructooligosaccharide; D006602:Hexosyltransferases; C021513:levansucrase