PURIFICATION AND CHARACTERIZATION OF AN EXTRACELLULAR ALPHA-AMYLASE FROM CLOSTRIDIUM-PERFRINGENS TYPE-A

An alpha-amylase (EC 3.2.1.1) secreted by Clostridium perfringens NCTC 8679 type A was purified to homogeneity and characterized. It was iso lated from concentrated cell-free culture medium by ion-exchange and g el permeation chromatography. The enzyme exhibited maximal activity at pH 6.5 and 30 degrees C without the presence of calcium. The pI of th e enzyme was 4.75, The estimated molecular weight of the purified enzy me was 76 kDa. The purified enzyme was inactivated between 35 and 40 d egrees C, which increased to between 45 and 50 degrees C in the presen ce of calcium (5 mM). The purified enzyme produced a mixture of oligos accharides as major end products of starch hydrolysis, indicating alph a-amylase activity.