Characterization of Fibrinolytic Enzyme from Bacillus altitudinis S-CSR 0020 and Its Clot-Degrading Capacity

Thrombosis, the major cause of heart disease, is on the rise owing to the current lifestyle habits of the population. Current treatments using thrombolytics, although successful, are plagued by side effects and costs. Fibrinolytic enzymes derived from microbial sources are ideal substitutes for chemical thrombolytics. Bacillus altitudinis S-CSR 0020, a soil bacterium, was shown to efficiently produce fibrinolytic enzyme. In this study, we further purified the enzyme using a combination of ammonium sulfate precipitation and ion-exchange chromatography to achieve a purification fold of 7.8 and a yield of 7%. SDS-PAGE and zymogram analysis revealed that the enzyme was 95 kDa in size and exhibited high stability across a broad pH range (6-11) and high temperature (30-60 ℃) even after 24 h incubation, along with an optimum pH and temperature of 9 and 40 °C, respectively. Further characterization revealed that the fibrinolytic activity was maximum at 4% fibrin concentration, and 3% ferric chloride and 5% β-mercaptoethanol enhanced enzyme activity. Functional analysis revealed that the purified enzyme efficiently removed preformed clots in the capillary and microfuge tubes and exhibited anticoagulant activity. No adverse effects were observed in the goat hepatic portal vein upon application of the fibrinolytic enzyme. This enzyme also displayed antibacterial activity against Staphylococcus aureus. The anticoagulant, clot-degrading potential, and non-toxic nature of the purified fibrinolytic enzyme highlight its potential application in the treatment of thrombosis.