The haloalkaliphilic bacterium Kocuria sp. (HJ014) has the ability to produce extracellular amylase. The aim of this study was to purify and characterize this protein. The amylase enzyme with a specific activity of 753,502 U/mg was purified 5.7- fold using Sepharose 4B and Sephacryl S-300 gel filtration columns. The molecular weight of the enzyme was 45,000 Da as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The amylase showed maximum activity at pH 9 and 50°C in the presence of 3.5 M NaCl. The Km was 3.0 mg/ml and Vmax 90.09 U/ml. It was found that extracellular amylase from Kocuria sp. has a high industrial potential.
Keywords: Haloalkaliphilic; enzyme molecular weight; industrial potential; specific activity.