Study On Screening,Mutation And Zymotechnique Of Strain Producing Fibrinolysin

The study on screening, mutation,fermentation conditions of liquid,solidon and 10Lfermenter onstrain producting plasmin activity. The study settle theory and application for industrializationproduction.the main results are as follows:Two strain bacterium and three mould of Producing Fibrinolysin screened were Screening fromtraditional fermentation bean products. The results showed that two strains were Bacillus subtilis accordingto strain appearance and physiology characteristic, named YB-1, YB-2. MJ-1,MJ-2 were head mold ormucor and MJ-3 was dry blue mold through strain initial characterization on strain character,shape,testunder microscope. MJ-3 is new strain of producting fibrinolysin in internal, screen two strain of stable, highplasmin activity YB-land MJ-3 ,Plasmin activity of YB-1 improved from 240IU/mLto 503IU/mL,increase 263IU/mL. Plasmin activity of MJ-3 improved from 72IU/g to 660U/g,increase 588IU/g withultraviolet mutation and ultraviolet- lithium chloride combination mutagenize.Study on fermentation conditions of strain YB-lincluding culture medium and culture conditions wasinvestigated. Finally the optimal fermentation conditions of YB-1 was confirmed: xylose 2%, tryptone 2%,K₂HPO₄0.3%, KH₂PO₄0.05%, CaCl₂·2H₂O0.015%,MgSO₄·7H₂O0.04%. culture temperature 37℃,initialpH7.0～7.2,inoculated volumes 7%, rotate speed 190rpm,fermentation time 72h Plasmin activity was630IU/mL under the optimal fermental conditions, After the system optimization,in the fermenter enlargestudy,the yield of fibrinolysin of 795IU/mL was obtained 72 hours later.Study on fermentation conditions of mould MJ-3 including culture medium and culture conditions wasinvestigated. Finally the optimal fermentation conditions of MJ-3 was confirmed: m(wheat bran):m(pea)1:3,pH 5.5,water 0.75mL/g materials, MnSO₄·H₂O 0.25%, (NH₄)₂SO₄1.4%, innoculation quantity 17.5%,fermentation temperature 30℃,fermentation time 72h.Under these condition, the mold'splasmin activitywas 873.76IU/g. MJ-3 is highest fibrinolysin in internal. High 81.95IU/g than product fibrinolysin fromhead mold.