K-063. Alternansucrase-Derived Prebiotic Oligosaccharides Enhance Enzyme Activity in Bifidobacterium

S. M. Holt1, J. M. Teresi2, G. L. Cote2;
1Western Illinois Univ., Macomb, IL, 2USDA, Peoria, IL.

The objective of this study was to determine the influence of alternansucrase-derived prebiotic oligosaccharides on enzyme activity in the beneficial colonic microbe Bifidobacterium adolescentis. Other carbohydrates were included for comparative purposes. Alternansucrase is a bacterial enzyme used to make prebiotic oligosaccharides and sweeteners. Fundamental knowledge of enzyme activity in Bifidobacterium may aid in the design of more effective prebiotics and may also help identify indicators of general metabolic activity when assessing their influence within the colon. Activities for α- and β-galactosidase and α- and β-glucosidase were determined from cell extracts of B. adolescentis grown on 18 test carbohydrates including alternansucrase-derived oligosaccharides. α and β-galactosidase activities were enhanced on a variety of β- or α-linked carbohydrates regardless if a galactoside or glucoside. α-Glucosidase, however, was enhanced only on α-carbohydrates. β-Glucosidase activity was not enhanced on any carbohydrate tested except for melibiose. Alternansucrase-derived oligosaccharides significantly enhanced α-galactosidase and α-glucosidase activities compared to most of the carbohydrates tested. Most of the alternansucrase-derived oligosaccharides showed significant increases in enzyme activity versus their corresponding acceptor carbohydrates. α and β-galactosidase may serve as biomarkers for microbial metabolic activity within the colon for potential prebiotics composed of α- or β-linked oligosaccharides whereas α-glucosidase activity may be restricted to assessing the influence of only α-linked carbohydrates. β-Glucosidase would probably not serve as a biomarker for microbial metabolic activity and does not seem to be significantly involved in carbohydrate degradation. In conclusion, the alternansucrase oligosaccharide synthesis process provided a value-added component to carbohydrates by increasing metabolic activity over certain acceptor carbohydrates.