Abstract: Three plasmin activity mold strains screened from traditional fermentation bean products. A mutant was obtained by isolation, purification and induced mutation. The results showed that two strains are determined as head molds or mucors while one strain is dry blue mold(Penicillium curinum Thom). Through initial determination on strain characteristics and microscope shape test, the plasmin activity is improved from 68 U/g, 56 U/g, 72U/g to 488 U/g, 416 U/g, 660 U/g respectively with ultraviolet mutation and ultraviolet- lithium chloride combination mutagenization.

Key words: fibrinolytic enzyme, screen, induction of mutation