CHARACTERIZATION OF THE IMMOBILIZED BETA-GALACTOSIDASE-C FROM BACILLUS-CIRCULANS AND THE PRODUCTION OF BETA(1-]3)-LINKED DISACCHARIDES

A recombinant beta-galactosidase, which was obtained from the beta-gal actosidase C gene of Bacillus circulans and cleaves the non-reducing e nd galactosyl residue of beta(1-->3)-linkages selectively, was immobil ized using CNBr-Sepharose. Although the effect of pH was not changed b y the immobilization, the thermostability and stability in the presenc e of DMF were increased. Optimization of the transglycosylation using para-nitrophenyl beta-D-galactopyranoside as a donor and benzyl-alpha- D-N-acetylgalactosaminide as an acceptor afforded a beta(1-->3)-linked disaccharide derivative with 62% molar yield in a gram scale synthesi s. Using the methyl-analogue as an acceptor, 53% of the acceptor was c onverted to the respective beta(1-->3)-disaccharide.