Properties of xylanolytic enzyme system in bifidobacteria and their effects on the utilization of xylooligosaccharides

The xylanolytic enzyme system was examined in Bifidobacterium adolescentis, B. infantis and B. bifidum to determine their ability to utilize xylooligosaccharides (XOSs). All these species produced only xylosidase and arabinosidase, and no xylanase, α-glucuronidase and acetyl xylan esterase were found. The optimal activity of β-d-xylosidase from B. adolescentis was at pH 5.6 and 45 °C, and α-l-arabinoside was at pH 5.0 and 40 °C. The degradation products of cell-free extracts and the growth rate of B. adolescentis were tested over XOSs and XOSs de-branched by recombinant α-glucuronidase. The results showed that de-branching α-glucuronidase increased the production of xylose and the total cell density by 10%, and accelerated the growth of B. adolescentis by 20%.