Purification of a Fibrinolytic Enzyme from Bacillus Sp. Isolated from Budu

Abstract

Bacillus sp. strain B1 producing wild type fibrinolytic enzyme was isolated from Budu. The fibrinolytic enzyme was collected from the supernatant of Bacillus sp. strain B1 culture broth and purified to electrophoretic homogeneity through a combination of various purification schemes, which include ammonium sulphate precipitation, followed by anion exchange chromatography using DEAE–Sepharose Fast Flow and gel filtration chromatography on Sephadex G–75 column. During ammonium sulphate precipitation screening, it was observed that the crude enzyme from Bacillus sp. strain B1 precipitated at 40% and 50% of ammonium sulphate saturation respectively. The fibrinolytic enzyme was purified 58.5–fold with a final yield of 0.51%. The specific activity was determined to be 1.17 Units/mg using plasmin as standard and the final total protein content was 8.58 mg/ml. After the successive purification steps, the estimated molecular mass of fibrinolytic enzymes from strain B1 was estimated via sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE). SDS–PAGE analysis showed a single band at 45 kDa corresponding to the purified fraction with fibrinolytic activity.