A thermostable maltose‐tolerant α‐amylase from Aspergillus tamarii

An homogeneous fraction of α‐amylase from Aspergillus tamarii was obtained by means of a very easy purification procedure. The enzyme is a glycoprotein containing 32% saccharide and MW of 37.5 kDa. Optimal of pH and temperature with starch as substrate were 4.5–6.5 and 50–55 °C. The enzyme was stable for several hours at temperature up to 65 °C. Starch, amylose, and amylopectin were the substrates preferentially hydrolysed and maltose and maltotriose were the main end products. The values of K M and V max for starch were 2 g/l and 880 μmoles reducing sugars/min.mg of protein, respectively. The purified enzyme was remarkably insensitive to end product inhibition, being only slightly inhibited by maltose and glucose up to 1.0 M .