Applied biochemistry and biotechnology

A novel dextran dextrinase from Gluconobacter oxydans DSM-2003: purification and properties.

PMID 22961394


Dextran has already been widely applied in food, pharmaceutical, and chemical industries. In this study, a novel intracellular dextran dextrinase (DDase, EC from Gluconobacter oxydans DSM-2003 exhibiting catalytic activity to synthesize dextran from maltodextrin was purified to homogeneity by ultrasonic cell disruption, ion exchange chromatography, and gel filtration. This procedure showed 187.5-fold purification from the cell-free extract with 41.9xa0% yield. And the apparent molecular weight was estimated to be 62xa0kDa by SDS-PAGE. It was different from the reported literatures, which found that the molecular weight of intracellular and extracellular DDase of G. oxydans ATCC-11894 was 300 and 152xa0kDa, respectively. Otherwise, it showed different physicochemical characteristics (optimal temperature and pH, thermal, pH stability, effect of metal ions) from the DDase of G. oxydans ATCC-11894. This indicated that DDase of G. oxydans DSM-2003 was a novel one compared to the reported literatures.