Purification and characterization of an extracellular thermostable alkaline α-amylase from the moderately halophilic bacterium, Bacillus persicus

Authors
S. Hadipour 1
H. Ghafoori 2
N. Sohrabi 1
M. Izaddoust 2
1 Department of Biology, Payam-e-Noor University, Tehran Branch, Pardis, Iran
2 Department of Biology, University of Guilan, Rasht, Iran
Abstract
Background: Today a large number of bacterial amylases are available commercially in industry. The goal of the present study was purification and biochemical characterization of an extracellular thermostable alkaline α-amylase from the novel moderately halophilic, Bacillus persicus
from the Aran-Bidgol, Iran.

Methods
: Purification of enzyme, was carried out by acetone precipitation, ultrafiltration and Q-Sepharose cation exchange chromatography.
Results
: The purified native enzyme showed a molecular mass of 53 kDa composed of a monomer by SDS–PAGE. The optimum pH, temperature and NaCl concentration were 10, 45 ∘C and 0.85 M respectively. It retained 50% of activity at 1.25 M NaCl and about 73% of activity at highly alkaline pH of 10.5, therefore it was a moderately halophilic and also can activate by divalent metal ions especially Ca2+ and Mg2+. The apparent values of Km and Vmax were obtained 1.053 mg/ml and 356μ/min respectively.
Conclusion
: In the present study we report the purification and characterization of a moderately halophilic α-amylase from a newly isolated Bacillus persicus. The purified enzyme shows interesting properties useful for industrial and biotechnological applications. The molecular cloning and structural studies of this α-amylase are in progress in our laboratory.
Molecular and Biochemical Diagnosis Journal
Volume 2, Issue 1
March 2016
Pages 79-94