Solubility of an Extracellular Alpha-Amylase from Bacillus Licheniformis
For several decades, crystallization has received increasing attention for the purification of industrial enzymes. In this study, the purification of an extracellular enzyme, alpha-amylase from Bacillus Licheniformis by crystallization was investigated. Alpha-amylases are an important category of industrial enzymes, widely used in starch hydrolysis, in the baking industry and in laundry powders and detergents. For the successful fundamental development of crystallization based purification processes, solubility data and nucleation and growth kinetics are required. However, such data are surprisingly very limited for alpha-amylases. The first focus of this study was therefore, to measure the solubility of the Bacillus Licheniformis alpha-amylase under different solvent conditions. Effects of temperature and pH within a practical range were examined. The use of different precipitants, such as sodium chloride, sodium sulphate and ammonium sulphate was also explored. The availability of these solubility data would facilitate the determination of the operating conditions and the purification yield of a crystallizer.