The action of a Lactobacillus bifidus dextranase on a branched dextran

Publisher Website
Google Scholar
Abstract
Lactobacillus bifidus dextranase has been shown to hydrolyze Leuconostoc mesenteroides (Birmingham strain) dextran to a complex mixture of oligosaccharides. In addition to isomalto-triose, -tetraose, -pentaose, -hexaose and unresolvable material of degree of polymerization greater than 6, a tetrasaccharide (A) and a pentasaccharide (B) were isolated. Tetrasaccharide (A) was shown to be a mixture of 33-glucosyliso-maltotriose and 32-glucosylisomaltotriose. Pentasaccharide (B) contained one glucose unit joined through a 1,3-linkage to a glucose unit, other than the reducing one, of isomaltotetraose and is probably a mixture of isomers. The dextranase has been shown to hydrolyze 6-O-[alpha]-iso-maltohexaosyl- and 6-O-[alpha]-isomaltoheptaosyl-sorbitol at 2 and 3 alternative glucosidic linkages respectively. The implications of the results, as far as dextranase action and dextran structure are concerned, have been discussed.