Two-step purification and partial characterization of an extra cellular α-amylase from Bacillus licheniformis

The aim of this study was production and partial purification of α-amylase enzyme by Bacillus licheniformis. B. Licheniformis was allowed to grow in broth culture for purpose of inducing α-amylase enzyme. Optimal conditions for amylase production by B. Licheniformis are incubation period of ۱۲۰ h, temperature of ۳۷ °C and pH ۷.۰. The α-amylase enzyme was purified by ion exchange chromatography on DEAE-sepharose CL-۶B and sephadex G-۱۰۰ gel filtration with a ۱۹.۱-fold increase in specific activity as compared to the concentrated supernatant and with a specific activity of ۹۲۶.۴۷ U/mg. The α-amylase had the highest activity at pH ۷.۰ and ۶۵ °C. According to the data on native polyacrylamide gel electrophoresis, the molecular weight of the purified enzyme was ۷۲ kDa.