Comparison of Fructooligosaccharide Utilization by Lactobacillus and Bacteroides Species

摘要

The utilization of 1-kestose (GF2) and nystose (GF3), the main components of fructooligosaccharides (FOS), by Lactobacillus and Bacteroides species was examined. Of seven Lactobacillus and five Bacteroides strains that utilized FOS, L. salivarius, L. rhamnosus, L. casei, and L. gasseri utilized only GF2, whereas L. acidophilus and all the Bacteroides strains utilized both GF2 and GF3. Only the strains able to utilize both GF2 and GF3 had β-fructosidase activity in the culture supernatants. The culture supernatants of the Lactobacillus strains had higher β-fructosidase activity for GF2 than for GF3, whereas those of the Bacteroides strains had higher activity for GF3 than for GF2. Furthermore, β-fructo-sidase activity of the culture supernatants of the Lactobacillus cells grown in the GF3 medium was much higher than that of the cells grown in the GF2 medium, whereas the activity of the culture supernatants of the Bacteroides cells grown in the GF3 medium was almost the same as that of the cells grown in the GF2 medium. These results indicate that Lactobacillus species metabolize FOS in a different way from that of Bacteroides species.