Characterization and optimization of α-amylase activity of Streptomyces clavifer

Abstract

Amongst seventeen previously identified Streptomyces species, S. crystallinus, S. noboritoensis, S. anulatus and S. clavifer were selected for α-amylase activity. All these species were grown in fermentation broth for α-amylase production in orbital shaker under optimum conditions. The fermentation broth cultures were then centrifuged at refrigeration temperature at 1000 rpm and supernatants were collected. The α-amylase from each supernatant was extracted by ammonium sulfate precipitation at 90% saturation and was dialyzed. The enzyme was assayed under standard assay conditions. Streptomyces clavifer was found to have the highest α-amylase activity amongst others. The effect of pH and temperature on α-amylase activity of Streptomyces clavifer was determined. The optimum pH and temperature for enzyme activity was found be 7.0 and 45°C, respectively. The enzyme was found stable at pH 6.0 to 8.0 and temperature upto 55°C. The kinetics of the enzyme was determined under standard conditions. The KM and the Vmax of the enzyme were determined as 4 mg and 0.03 mg sec -1, respectively. α-amylase together with other amylolytic enzymes have tremendous applications in textile industries, confectioneries, pharmaceutical industries and other food industries as hydrolyzing bioagents. © 2006 Asian Network for Scientific Information.