Microbial Production and Characterization of Dextranase

Abstract

In sugar production, dextrans (undesirable compounds) synthesized by contaminant microorganism from sucrose. Formation of dextran increases the viscosity of the flow, reduces industrial recovery, and causes significant losses. The use of dextranase is the most efficient method for hydrolyzing dextrans at sugar mills. Some bacterial, fungal and yeast strains have been studied to produce dextranase. Penicillium aculeatum NRRL-896 showed the highest production rate after 7 days of incubation. The highly purified enzyme was simply separated and purified by sequential DEAE-Sepharose and Sephadex G-100 columns, 42.8 fold with 14.78 yield.The enzyme exhibited an apparent molecular weight of 66,200 Da, a temperature optimum of 45 C and a pH optimum of 4.5.The enzyme was extremely stable for 60 min at 35-45 C. The Km value of the purified dextranase was 52.13±0.02 mg ml-1indicating that the enzyme had a very high specificity for dextran.