Isolation and identification of Bacillus megaterium producing Alkaline α-amylase

A bacterial strain, Bacillus megaterium L-49 has been isolated and identified that produces alkaline a-amylase. The cell is ellipsoidal, about 1.0-1.2 × 3.0-3.6 ㎛ in diameter, Gram-positive, motile, and central partial central. Growth occurs in media containing 7% of NaCl. This strain could utilize D-glucose, lactose, xylose, sucrose, mannose, and maltose, and but it does not utilize D-fructose, and glycogen. Among the various concentrations of saturated ammonium sulfate, the retractation ratio in range of 70 to 100% was about 93%. However, in the case of acetone, it was about 98.7%. EDTA has activating effect and Ca2+ has no effect on alkaline α-amylase activity. The alkaline a-amylase has low thermal stability. The optimal temperature for reaction is 50℃The alkaline a-amylase activity maintained stabilizing at pH 6-11 and the optimal pH for reaction was 9-10.