The study of extracellular fibrinolytic enzyme from non-hemolytic bacterium, Bacillus sp. DJ-1 screened from Doen-Jang = 된장으로부터 분리한 비용혈성 균주, Bacillus sp. DJ-1 의 세포 외 혈전용해효소에 대한 연구

Abstract

Background: The study on the fibrinolytic enzyme from Bacillus strain isolated from Doen-Jang, a Korean traditional fermented food, was reported previously by authors. Now we described here about the extracellular fibrinolytic enzyme (EFE) from a useful non-hemolytic bacterium, Bacillus sp. DJ-1 obtained from the same sauce. Methods: Fibrin and casein plates, and fibrin zymography methods were used to study the EFE from Bacillus sp. DJ-1, which showed no hemolytic activity. Results: Total curde EFE of Bacillus sp. DJ-1 showed the maximal enzyme activity (3.42 plasmin NIH unit/mL) and the highest specificity (1.52 F/C, the ratio of fibrinolytic activity to caseinolytic activity) after 33 hour (pick point of cell density), based on the molar ratio. Three major bands from the culture supernatant of Bacillus sp. DJ-1 were identified on the zymography gel with 0.12% fibrin, corresponding to the molecular masses of 26.8, 22.6 and 21.5 kDa during the cell wall lysis phase. Using fibrin zymography inhibitor assay, these three enzymes were revealed as a serine protease. Among them, 26.8 kDa EFE band was analyzed its density with densitometer according to the culture time. Conclusions : In this study, we demonstrated the property of the EFE from non-hemolytic Bacillus sp. DJ-1 based on the fibrinolytic assay systems, plate method, zymographic technique, and densitometric analysis.