Formation of oligosaccharides from lactose by Bacillus circulans beta-galactosidase

Eleven oligosaccharides formed by a transglycosylation reaction during lactose hydrolysis with Bacillus circulans beta-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 beta-D-Galp-(1-->3)-D-Glc, beta-D-Galp-(1-->6)-D-Glc, beta-D-Galp-(1-->2)-D-Glc, beta-D-Galp-(1-->4)-beta-D-Galp-(1-->4)-D-Glc, beta-D-Galp-(1-->6)-[beta-D-Galp-(1-->2)]-D-Glc, beta-D-Galp-(1-->6)-[beta-D-Galp-(1-->4)]-D-Glc, beta-D-Galp-(1-->4)-beta-D-Galp-(1-->3)-D-Glc, beta-D-Galp-(1-->4)-beta-D-Galp-(1-->2)-D-Glc, beta-D-Galp-(1-->4)-[beta-D-Galp-(1-->2)]-D-Glc, beta-D-Galp-(1-->4)-beta-D-Galp-(1-->6)-D-Glc, beta-D-Galp-(1-->6)[beta-D-Galp-(1-->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 oligosaccharides containing lactose units were predominantly used by human intestinal bifidobacteria.