Abstract
Dextrin dextranase (EC 2.4.1.2), which synthesizes dextran from maltooligosaccharides, was purified from Acetobacter capsulatus ATCC11894 cells by n-butanol extraction, Phenyl-Toyopearl chromatography, and Toyopearl HW-65S gel filtration. The molecular weight of this enzyme was 300, 000 by SDS-gradient-PAGE. The optimum temperature and pH were 37-45°C and 4.0-4.2. The enzyme was stable at below 45°C and at pH 3.5-5.2 for 30 min treatment. This enzyme synthesized dextran from maltooligosaccharides except for maltose, from which a little glucose and panose were produced. On the reaction with G4, the enzyme synthesized dextran and also maltose, panose, and a small amount of glucose as byproducts. Acetobacter dextran synthesized from G4 was compared with commercial Leuconostoc dextran by dextranase digestion, and it was suggested that these structures were different from each other.
