|Cote, Gregory - Greg|
Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 7/28/2006
Publication Date: 7/28/2006
Citation: Holt, S.M., Hansen, J.M., Cote, G.L. 2006. New prebiotic carbohydrates enhance enzyme activity in bifidobacterium [abstract]. 8th Biennial Congress of the Anaerobe Society of the Americas. p. 00. Interpretive Summary:
Technical Abstract: Bifidobacterium inhabit the human intestine and are considered beneficial due to their health-promoting activities. Prebiotic carbohydrates have been used as supplements to selectively promote growth of bifidobacteria within the intestine. The mechanism of prebiotic metabolism by Bifidobacterium, however, is poorly understood. The objective of this study was to determine the influence of prebiotic carbohydrates on enzyme activity in Bifidobacterium. Seventeen carbohydrates were used in this study and included a prebiotic fructooligosaccharide and newer alternansucrase-derived oligosaccharides (AOS). AOS have been shown in a previous study to stimulate growth of certain bifidobacteria. B. adolescentis was grown anaerobically for 48 hrs on each test carbohydrate and enzyme activities (alpha-galactosidase and alpha-glucosidase) were determined from the cell extracts. Both enzymes were detected on all carbohydrates tested including glucose indicating that a basal level of each enzyme was always expressed. Each enzyme displayed a significantly different pattern in activity toward the battery of test carbohydrates. For alpha-galactosidase 14 carbohydrates showed a significant increase in activity. The alpha-linked carbohydrates showed higher increases in activity compared to the beta-linked carbohydrates. For alpha-glucosidase, however, only seven of the carbohydrates showed a significant increase in activity. Carbohydrates containing either a beta-link or alpha beta-link showed no significant increase in activity for alpha-glucosidase. Alpha-Galactosidase showed a significant activity increase on five carbohydrates that alpha-glucosidase did not. Expression of each enzyme appeared to be controlled by different mechanisms. Alpha-Galactosidase appeared to be less stringently controlled than alpha-glucosidase since most carbohydrates displayed a significant increase in activity on the former enzyme. The highest activities for both enzymes were obtained on several of the AOS prebiotic carbohydrates. In addition, most of the AOS prebiotic carbohydrates showed significant increases in activity for both enzymes over that displayed by their corresponding acceptor carbohydrates. In conclusion, the AOS prebiotic carbohydrates significantly enhanced enzyme activity in the beneficial bacterium B. adolescentis compared to most of the carbohydrates tested. Alpha-Galactosidase is an important enzyme in carbohydrate metabolism in B. adolescentis.