Abstract
The hydrolysis of copra galactomannan (Gal: Man≅1: 14) by the purified β-mannanase IV from Streptomyces sp. No. 17 produced seven kinds of oligosaccharides, that is, three kinds of β-1, 4-mannooligosaccharides (D.P.=2, 3 and 4) and four kinds of galactomanno-oligosaccharides (Gal : Man=1: 4, 1: 5, 2: 5 and 2: 6) . The structural study of the oligosaccharides showed that galactomannan is composed of the main-chain of 1, 4-linked β-D-mannosyl residues to which single α-D-galactosyl branches at the O-6 position of D-mannosyl residue are attached.
All the reducing- and non-reducing-ends of the galactomanno-oligosaccharides were D-mannosyl residues devoid of an α-galactosyl branch. Thus, it is concluded that the enzyme has a specificity to the D-mannosyl residues of the main-chain devoid of an α-galactosyl branch.
