Strain Improvement of Streptomyces venezuelae for Enhanced Fibrinolytic Enzyme Production

摘要

The fibrinolytic enzymes can be used as a potential drag to cure thrombosis diseases. These enzymes can effectively catalyze the degradation of fibrin in blood clot. To develop safe and cheaper fibrinolytic agents, fibrinolytic enzyme was isolated from Streptomyces venezuelae. Strain improvement was employed to increase the production of fibrinolytic enzymes using random mutagenesis (UV and Ethyl methane sulfonate). The mutants obtained were screened based on their fibrinolytic activity and best mutant was selected for further studies. Mutant obtained by Ethyl Methane Sulfonate was able to yield the fibrinolytic activity of 13 FU/mL in growth medium which was higher than wild strain (6 FU/mL). The results indicated that EMS was effective mutagenic agents for strain improvement of Streptomyces venezuelae for enhanced production of fibrinolytic enzyme. The mutant showed improved growth compared to wild strain. The optimal temperature and pH value of this fibrinolytic enzyme were found to be 40 °C and 8.0, respectively. The strain improvement also improves the stability of Streptomyces venezuelae which showed resistance to temperature and pH at higher values. Invitro assays revealed that fibrinolytic enzyme produced by Streptomyces venezuelae could degrade fibrin suggesting that its future application in pharmaceutical industry as thrombolytic agent is highly promising.