Studies on dextranase from Penicillium aculeatum

A strain of Penicillium aculeatum has been found to synthesize large quantities of dextranase (1,6-α-d-glucan 6-glucanohydrolase, EC 3.2.1.11) in culture filtrate. Some of the conditions governing the enzyme production have been standardized. The enzyme in crude state was found to be highly stable, its activity being maximum at 50 to 60°C and at pH 5 to 6. About 90% of the substrate dextran was converted to isomaltose in a 4 h period at 40°C. The enzyme when purified by salt and solvent fractionation gave 1500 units per mg protein and retained its activity over a long period when stored at 4°C.