In vitro kinetic analysis of fermentation of prebiotic inulin-type fructans by Bifidobacterium species reveals four different phenotypes.
Kinetic analyses of bacterial growth, carbohydrate consumption, and metabolite production of 18 Bifidobacterium strains grown on fructose, oligofructose, or inulin were performed. A principal component analysis of the data sets, expanded with the results of a genetic screen concerning the presence of a beta-fructofuranosidase gene previously encountered in Bifidobacterium animalis subsp. lactis DSM 10140(T), revealed the existence of four clusters among the bifidobacteria tested. Strains belonging to a first cluster could not degrade oligofructose or inulin. Strains in a second cluster could degrade oligofructose, displaying a preferential breakdown mechanism, but did not grow on inulin. Fructose consumption was faster than oligofructose degradation. A third cluster was composed of strains that degraded all oligofructose fractions simultaneously and could partially break down inulin. Oligofructose degradation was substantially faster than fructose consumption. A fourth, smaller cluster consisted of strains that shared high fructose consumption and oligofructose degradation rates and were able to perform partial breakdown of inulin. For all strains, a metabolic shift toward more acetate, formate, and ethanol production, at the expense of lactate production, was observed during growth on less readily fermentable energy sources. No correlation between breakdown patterns and the presence of the beta-fructofuranosidase gene could be detected. These variations indicate niche-specific adaptation of bifidobacteria and could have in vivo implications on the strain specificity of the stimulatory effect of inulin-type fructans on bifidobacteria.
Falony
Gwen
G
Research Group of Industrial Microbiology and Food Biotechnology, Department of Applied Biological Sciences and Engineering, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
Lazidou
Katerina
K
Verschaeren
An
A
Weckx
Stefan
S
Maes
Dominique
D
De Vuyst
Luc
L
D019342:Acetic Acid / Q000378:metabolism; D001644:Bifidobacterium / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D016000:Cluster Analysis; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005561:Formates / Q000378:metabolism; D005630:Fructans / Q000378:metabolism*; D005632:Fructose / Q000378:metabolism; D007444:Inulin / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism; D010641:Phenotype; D043324:beta-Fructofuranosidase / Q000235:genetics
D005561:Formates; D005630:Fructans; D009844:Oligosaccharides; C120489:oligofructose; C030544:formic acid; D005632:Fructose; D019344:Lactic Acid; D000431:Ethanol; D007444:Inulin; D043324:beta-Fructofuranosidase; D019342:Acetic Acid