Alpha-amylase (E.C.18.104.22.168) plays a great role as it has multiple applications in various industries. At present, its production has reached up to 65% of the enzyme market in the world and is continuously increasing. Alpha-amylase is produced by a variety of living organisms ranging from bacteria to plants and animals. The specific activity of α-amylase is dependent on various biochemical phenotype parameters such as substrate, pH, and temperature as well as metal ions requirements. Potato starch with a concentration of 5 mg/ml was found to be more enzyme-specific (34.02 IU/mg of protein) as substrate compared to other variety of starch. The enzyme was best active at pH 8.0 and incubation temperature of 37°C using Na2+as metal ions. The findings suggest that enzyme activity increases up to a certain concentration then decreases, structural properties also influence the enzyme activity. The optimum temperature and pH of enzyme activity are also dependent on the microbial strain used. Competition between the exogenous cations and the protein-associated cation decreases metalloenzyme activity. Therefore, this study was aimed to determine the specificity of isolated α-amylase by variety of substrate, pH, incubation temperature and metal ions by giving a crucial comparison between each of the parameter of the standard assay.
Key words: Amylase, Aspergillus oryzae, Metal ions, Optimum pH, Substrate specificity, Temperature.