Mathew C.D. and Rathnayake S.
This paper describes the purification and characterization of a thermostable α-amylase produced by Geobacillus sp. NMS 2 isolated from soil samples of a hot water spring in Nelumwewa, which is situated in the Polonnaruwa district of Sri Lanka. The microorganism isolated was identified by morphology, biochemical tests and 16S rRNA gene sequencing. Optimum extracellular enzyme production was 43 U/ml after 12 hours incubation at 500C. The enzyme was purified by extraction, ammonium sulphate fractionation and DEAE chromatography. The specific activity of the purified enzyme was 420 U/mg with a folds purification 2.8. Polyacrylamide gel electrophoresis showed only one protein band. From Lineweaver- Burke plot, the Km and Vmax values were 3.4 mg/ml and 460 μmolmin-1mg-1 respectively. The enzyme was stable at temperatures from 10oC to 600C with the optimum activity at 500C. Geobacillus sp. NMS 2 α-amylase showed optimum activity at pH 6.9 and it was stable at pH ranges from 6.9 to 9.
Share this article