Characterization of α-amylase purified from Thermophilic Bacillus spp.

Abstract

Partial characterization of α-amylase purified from Thermophilic Bacillus spp. were studied by using ammonium sulfate and ion-exchange. The results of gel-filtration were demonstrated that the molecular weight of purified enzyme was 51285 Dalton. The optimum pH for enzyme’s activity was pH = 9 and the enzyme showed stability at pH in the range pH 9 – 7. The optimum temperature for the enzyme’s activity was 70 C̊ and the enzyme showed thermo stability between 40 C̊ to 70 C̊ to 15 minutes. The value of activation energy to convert the substrate (starch) into products reached to 9.56 kcal /mol. The averages value of Mechalis constant (km) and maximum velocity of enzyme (Vmax) were 0.72%, 10.4 mM/min respectively. The EDTA and NaN3 inhibits α-amylase activity while the calcium chloride increases the enzyme activity and thermostability 145%, 70 to 90 C̊ for 10 minutes respectively, when adding 0.3 mM calcium chloride to the reaction solution. Introduction