Fermentation of Fructooligosaccharides and Inulin by Bifidobacteria: a Comparative Study of Pure and Fecal Cultures
The utilization of fructooligosaccharides (FOS) and inulin by 55 Bifidobacterium strains was investigated. Whereas FOS were fermented by most strains, only eight grew when inulin was used as the carbon source. Residual carbohydrates were analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection after batch fermentation. A strain-dependent capability to degrade fructans of different lengths was observed. During batch fermentation on inulin, the short fructans disappeared first, and then the longer ones were gradually consumed. However, growth occurred through a single uninterrupted exponential phase without exhibiting polyauxic behavior in relation to the chain length. Cellular β-fructofuranosidases were found in all of the 21 Bifidobacterium strains tested. Four strains were tested for extracellular hydrolytic activity against fructans, and only the two strains which ferment inulin showed this activity. Batch cultures inoculated with human fecal slurries confirmed the bifidogenic effect of both FOS and inulin and indicated that other intestinal microbial groups also grow on these carbon sources. We observed that bifidobacteria grew by cross-feeding on mono- and oligosaccharides produced by primary inulin intestinal degraders, as evidenced by the high hydrolytic activity of fecal supernatants. FOS and inulin greatly affected the production of short-chain fatty acids in fecal cultures; butyrate was the major fermentation product on inulin, whereas mostly acetate and lactate were produced on FOS.
- SCFA profiles of two fecal cultures after 24 h of incubation on FOS and inulin as the sole carbon sources
- B-fructofuranosidase activity detected in permeabilized cells of 21 Bifidobacterium pure cultures during the growth phase on glucose FOS and inulin as the sole carbon source
- Small-scale pH-controlled batch fermentations of Bifidobacterium sp. ALB3 in SM containing 10 g liter -1 inulin as the sole carbon source
- Small-scale batch fermentations with controlled pH of B. adolescentis MB 239 in SM containing 10 g liter -1 FOS as the sole carbon source – growth curve and changes in fructan composition monitored by HPAEC-PAD are shown. DW dry weight
- Comparison of HPAEC-PAD patterns of SM containing 10 g liter -1 inulin at the inoculation and after 48 h of incubation with B. adolescentis ALB1
- Comparison of HPAEC-PAD patterns of SM containing 10 g liter -1 FOS at the inoculation after 48 h of incubation with B. infantis ATCC 27920
- Comparison of HPAEC-PAD patterns of SM containing 10 g liter1 FOS or 10 g liter1 inulin at the inoculation and after 48 h of incubation with B thermophilum ATCC 25866
- Species, strains, and sources of 55 bifidobacteria examined for the ability to ferment glucose, FOS, and inulin
Rossi, M., Corradini, C., Amaretti, A., Nicolini, M., Pompei, A., Zanoni, S., & Matteuzzi, D. (2005). Fermentation of fructooligosaccharides and inulin by bifidobacteria: a comparative study of pure and fecal cultures. Appl. Environ. Microbiol., 71(10), 6150-6158.