A Bacillus sp. producing a new fibrinolytic enzyme was screened from a fermented fish known as Jeot-Gal in Korea. The enzyme was purified to electrophoretic homogeneity using consecutive procedures including ammonium sulfate fractionation and column chromatography. The enzyme was highly specific toward fibrin clots and directly degraded them. The molecular weight was 41 kDa and the first 10 amino acids of the N-terminal sequence was Val-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-Pro-Asn. Optimal fibrinolytic activity was observed at pH 7.0 and 40 degrees C, and the specific activity was above 1.4 U/mg when determined with plasmin as a standard. The fibrinolytic activity was stimulated with zinc ions and repressed by various metalloprotease inhibitors, which indicates that the enzyme is a novel metalloprotease.