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 120 h, temperature of 37 °c and ph 7.0. the α-amylase enzyme was purified by ion exchange chromatography on deae-sepharose cl-6b and sephadex g-100 gel filtration with a 19.1-fold increase in specific activity as compared to the concentrated supernatant and with a specific activity of 926.47 u/mg. the α-amylase had the highest activity at ph 7.0 and 65 °c. according to the data on native polyacrylamide gel electrophoresis, the molecular weight of the purified enzyme was 72 kda.