Production of amylases by Aspergillus tamarii

A strain of Aspergillus tamarii, a filamentous fungus isolated from soil, w as able to produce both alpha-amylase and glucoamylase activities in minera l media supplemented with 1% (w/v) starch or maltose as the carbon source. Static cultivation led to significantly higher yields than those obtained u sing shaking culture. The production of amylases was tolerant to a wide ran ge of initial culture pH values (from 4 to 10) and temperature (from 25 to 42 degrees C). Two amylases, one alpha-amylase and one glucoamylase, were s eparated by ion exchange chromatography. Both partially purified enzymes ha d optimal activities at pH values between 4.5 and 6.0 and were stable under acid conditions (pH 4.0-7.0). The enzymes exhibited optimal activities at temperatures between 50 degrees and 60 degrees C and were stable for more t han ten hours at 55 degrees C.