Production and Properties of Alkaline Dextranase from a Newly Isolated Brevibacterium

Abstract

About 500 strains of dextranase producing microorganisms were examined in detail for pH-activity and enzyme stability. A gram positive bacterium identified as belonging to the genus Brevibaeterium was found to produce alkaline dextranase. Maximal dextranase synthesis was obtained when grown aerobically at 26°C for 3 days in a medium containing 1% dextran, 2% ethanol, 1% polypeptone and 0.05% yeast extract together with trace amounts of inorganic salts.
Brevibacterium dextranase had an optimum pH of 8.0 for activity at 37°C and an optimal temperature at 53°C at pH 7.5. The enzyme was quite stable over the range of pH 5.0 to 10.5 on 24 hr incubation at 37°C, especially on alkaline pH. The enzyme was also heat stable at 60°C for 10min.