Authors : Bahri Devrim Ozcan, Makbule Baylan, Numan Ozcan and Dilek Tekdal
Abstract: Bacillus sp. DM-15 was isolated from Çiftehan Thermal Spring, Turkey produced thermostable α-amylase at 55°C at pH 9. Analysis of the enzyme for molecular mass and amylolytic activity carried out by SDS-Starch-PAGE electrophoresis revealed a single band with high molecular mass 126 kDa. After extraction, the enzyme remained stable in a range of temperature and pH between 40-100°C and 4.5-10, respectively. The optimum enzyme activity was displayed at 60°C and pH 5.5-6.0. α-amylase production by thermophilic Bacillus sp. strain cultivated in liquid media reached a maximum at 12 h with levels of 27.5 μmol mg-1 protein min-1. The enzyme was stable for 15 min at 60°C while 24% of the original activity was lost at 100°C. Enzyme activity was increased in the presence of 5 mM CaCl2, Na2SO3 and KCl (105%) and inhibited in the presence of 5 mM EDTA, CuSO4, FeSO4, SDS (1%), Urea (8 M), Co up to 98, 79, 57, 36, 33 and 10%, respectively. The DM-15 α-amylase may be suitable for in liquefaction of starch in detergent and textile industries and in other industrial applications.
Bahri Devrim Ozcan, Makbule Baylan, Numan Ozcan and Dilek Tekdal, 2010. Characterization of Thermostable α-amylase from Thermophilic andAlkaliphilic Bacillus sp. Isolate DM-15. Research Journal of Biological Sciences, 5: 118-124.