Characterization of Amylase Produced by Thermophilic Bacillus sp. TS9

Abstract

Amylases constitute the second largest group of enzymes in the world enzyme market and are produced by many bacterial and fungal strains. The potent producer of amylase is Bacillus due to the production of thermostable enzymes that can withstand harsh conditions in industrial bioprocess. The α-amylase produced by Bacillus sp. TS9 was purified through gel filtration chromatography and then crude, partially purified and purified α-amylase was characterized. The crude, partially purified and purified amylase showed stability to a wide range of temperature (35-80°C) and pH (6-9) with optimum temperature and pH is 55°C and 9 respectively. The purified amylase also retained 70% of its activity at 100°C after incubation of 3 hours. The crude, partially purified and purified amylase showed stability to Na +1 and Mg +2 , methanol, and commercial detergents, less affected by Zn+2 , (NH4)2SO4, Triton-X-100, Tween-80 and SDS and some solvents but its activity was reduced by Ca +2 and Hg +2 . The amylase obtained from Bacillus sp. TS9 is Ca+2 independent as don’t require Ca +2 ions for its activity, but still the purified amylase was sensitive to EDTA to some extent. Its activity was completely inhibited by mercapto-ethanol revealing that histidine residues are present at the active site of an enzyme. As the amylase obtained from thermophilic Bacillus sp. TS9 showed stability to high temperature and pH, solvents, metal ions, detergents, and surfactants, so can be utilized in starch processing, detergent, textile, and food industries.