Screening And Fermentation Conditions Optimizing Of High Activity Fibrinolytic Enzyme Strains

Thrombus is a kind of disease which leads to tip top death rate in clinic for the moment. Scientists of medicine vocation are always paying attention to searching of deliquescent thrombus medicament in the world. And people have been developing the novel medicine to this day.In this paper, the experiment had screened two superiority strains from 220 kinds of sample in Hebei that can produce the higher activity fibrinolytic enzyme, and fermentation conditions, including medium, inoculation quantity, strain age, pH, OD, rpm, had been optimized. Finally, the experiment made certain better fermentation conditions, activity of thick enzyme and identified the strains.1 The experiment confirmed the fibrinolytic enzyme activity which was produced by two stains and that HFl HF3 was objective strains through first screening with casein flat and second screening with fibrin flat. So the study screened the strains, producing fibrinolytic enzyme, and determined effect of dissolving thrombus outside body, which found a kind of effective way of screening and provided the usable parameter for dissolving thrombus experiment inside body and the development of medicine.2 Fermentation conditions of HFl and HF3 were optimized through single factor test and orthogonal design study. The conclusion was as follows:(1) HFl stain: xylose 2%, soybean peptone 3%, Na₂HPO₄ ." NaH₂PO₄ (%) 0.1 : 0.1,MgSO₄ 0.05%,CaCl₂ 0.02%, Tween40 0.2%, stain age 14h, inoculation quantity 2%, fermentation period 3d, original pH 7.0, rotate speed 200r/min, OD 50mL/500mL, temperature 37℃, fibrinolytic enzyme activity 864.9(UK IU/mL).(2) HF3 stain: xylose 2%, soybean peptone 3%, Na₂HPO₄ I NaH₂PO₄ (%) 0.1 : 0.1,MgSO₄ 0.1%,CaCl₂ 0.01%, Tween40 0.2%, stain age 18h, inoculation quantity 2%, fermentation period 3d, original pH 7.0, rotate speed 200rpm, OD 50mL/500mL,temperature 37℃,fibrinolytic enzyme activity 862.2(UK IU/mL).(3) Compared to correlative study, fibrinolytic enzyme activity of HF1 and HF3 strain ishigher.3 This paper identified that both HF1 and HF3 were Bacillus by comparing of the conformation characteristics, and the physiological and biochemical characteristics and G+C mol % with Bacillus.