Transgalactosylation products from melibose by the alpha-galactosidase of Absidia corymbifera.

such a galactosyl transfer reaction as well as the decomposition of raffinose in beet sugar production, they may also produce galactooligosaccharides. Mitutomi and OhtakaraX) reported the isolation and identification of six main oligosaccharides produced from raffinose by the action of the a-galactosidase from Pycnoporus cinnabarinus. In our preliminary experiments, however, the a-galactosidase from A. corymbifera was observed to synthesize only two transfer products from raffinose. When melibiose was used as substrate, nine transfer products were detected. As sugar beet roots contain a significant level of invertase activity, raffinose is probably changed into melibiose in the early stages of sugar-refining process. In this paper we described isolation and characterization of three major transgalactosylation products from melibiose. a-Galactosidase was purified from cell pellets of A. corymbifera by the method of Honjo et al.2) Galactinol and melibiose were prepared by extracting from molasses and by decomposing raffinose using immobilized bakers' yeast, respectively.