TY  - JOUR
AU  - Al-Quadan, Farouk 
AU  - Akel, Hazem 
AU  - Natshi, Rasha 
PY  - 2009
TI  - Characteristics of a Novel Highly Thermostable and Extremely Thermophilic Alkalitolerant Amylase from Hyperthermophilic Bacillus Strain HUTBS71
JF  - OnLine Journal of Biological Sciences
VL  - 9
IS  - 3
DO  - 10.3844/ojbsci.2009.67.74
UR  - https://thescipub.com/abstract/ojbsci.2009.67.74
AB  - Problem statement: This study reported the purification and characterization of a novel highly thermostable alkaline amylase from a newly isolated Bacillus strain HUTBS71. Approach: The enzyme was purified using ammonium sulfate precipitation, ion exchange and gel filtration chromatography. Results: Maximum amylase activity (72 U mL-1) was obtained at 100°C after 10 min of incubation. The enzyme was purified 24 fold with 12.5% yield and showed a monomer band with a molecular weight of 58.8 kDa by SDS-PAGE. This enzyme exhibited maximum activity at pH and temperature, 7.8 and 100°C, respectively. It performed stability over a broad range of pH and temperature, 5.2-10.0 and 80-115°C, respectively. The half-life of the enzyme at 90 and 100°C was estimated to be 3 h. The activation energy of denaturation of purified enzyme was 2.53 kJ moL-1. The enzyme was activated by 5 mM of CoCl2, MgSO4, MnCl2, ZnSO4 and MnSO4 (relative activity was 133, 126, 133, 106.6 and 103%, respectively). It was strongly inhibited by CuSO4 and CdCl2 but less affected by NaCl, CaCl2, FeCl3, ZnCl2 and EDTA. Conclusion: The present purified amylase therefore could be defined as a highly thermostable, extremely hyperthermophilic and alkalitolerant with new properties make the present enzyme applicable for many starch processing and food industries.