Formation of Oligosaccharides from Lactose byBacillus circulans β-Galactosidase

Eleven oligosaccharides formed by a transglycosylation reaction during lactose hydrolysis with Bacillus circulans β-galactosidase were purified by gel permeation chromatography, charcoal chromatography, and HPLC. From the results of methylation analysis, and MS and NMR studies, it was concluded that these oligosaccharides were β-D-Gal p-(1 → 3)-D-Glc, β-D-Gal p-(1 → 6)-D-Glc, β-D-Gal p-(1 → 2)-D-Glc, β-D-Gal p-(1 → 4)-β-D-Gal p-(l → 4)-D-Glc, β-D-Gal p-(l → 6)-[β-D-Gal p-(1 → 2)]-D-Glc, β-D-Gal p-(l → 6)-[β-D-Gal p-(1 → 4)]-D-Glc, β-D-Gal p-(1 → 4)-β-D-Gal p-(1 → 3)-D-Glc, β-D-Gal p-(1 → 4)-β-D-Gal p-(1 → 2)-D-Glc, β-D-Gal p-(1 → 4)-[β-D-Gal p-(1 → 2)]-D-Glc, β-D-Gal p-(1 → 4)-β-D-Gal p-(1 → 6)-D-Glc, β-D-Gal p-(1 → 6)[β-D-Gal p-(l → 3)]-D-Glc. The last five are newly observed oligosaccharides. The results of a use test (in vitro) by human intestinal bacteria showed that the oligo saccharides containing lactose units were predominantly used by human intestinal bifidobacteria.