Isolation and identification of a fibrinolytic bacterium strain from frozen soil in the Tibetan Plateau

Abstract:

Abstract: [Objective] Cardiovascular disease, harmful to human health, is a worldwide disease, for which fibrinolytic enzyme is usually used as an effective remedy. Fibrinolytic microbes under extreme environmental conditions may excrete some high efficient and safe fibrinolytic enzymes. So, for obtaining this fibrinolytic enzyme, we isolated fibrinolytic strains from frozen soil in the Tibetan Plateau. [Methods] We screened microbes hydrolyzing blood powder by blood powder (bovine)-agar plate, followed by detection of thrombolysis effect through thrombolytic test in vitro. After that, we detected and measured the fibrinolytic activity of those microbes screened above with fibrin plates. Finally, we classified and identified the fibrinolytic microbes by combining physiological and biochemical test and 16S rRNA gene sequence analysis. [Results] We isolated a strain DR-536 from frozen soil at 4300 m altitude in Yushu Tibetan Autonomous Prefecture, Qinghai Province. We found that the strain DR-536 not only hydrolyzed blood powder in the blood-agar plate, but also completely dissolved thrombus in vitro. We also found that strain DR-536 could hydrolyze fibrin, and the fibrinolytic activity was 51.80 IU/ml (with Urokinase as a standard). At last, results of classification and identification indicated that DR-536 is a new strain of Arthrobacter aurescens with fibrinolytic function. [Conclusion] We provided a strain for research and exploitation of novel fibrinolytic enzymes.