Isolation and identification of a novel fibrinolytic Bacillus tequilensis CWD-67 from dumping soils enriched with poultry wastes

A newly isolated strain, CWD-67, which exhibited high fibrinolytic activity, was screened from dumping soils enriched with poultry wastes. The strain was identified as Bacillus tequilensis (KF897935) by 16Sr RNA gene sequence analysis and biochemical characterization. A fibrinolytic enzyme was purified to homogeneity from the culture supernatant using ammonium sulfate precipitation, membrane concentration, dialysis, ion-exchange, and gel filtration chromatography. SDS-PAGE analysis showed that the purified enzyme was a monomeric protein with an apparent molecular weight of 22 kDa, which is the lowest among Bacillus fibrinolytic enzymes reported to date. The purified enzyme was confirmed to have fibrinolytic activity by a fibrin zymogram. The optimal pH and temperature values of the enzyme were 8.0 and 45 degrees C, respectively. The enzyme was completely inhibited by PMSF and significantly inhibited by EDTA, TPCK, Co2+, Zn2+, and Cu2+, suggesting a chymotrypsin-like serine metalloprotease. In vitro assays revealed that the purified enzyme could catalyze fibrin lysis effectively, indicating that this enzyme could be a useful fibrinolytic agent.