原生质体紫外诱变选育纳豆激酶高产菌株

Screening High-yield Nattokinase Producing Strain by Protoplast Mutagenagsis with UV

以纳豆菌B.N.K为出发菌株,在适宜条件下制备和再生原生质体,并结合紫外线诱变筛选纳豆激酶高产菌株。经过原生质体紫外诱变的重复处理、摇瓶复筛和遗传稳定性试验,最终得出5株高产菌株即DU104、DU115、DU120、DU212、DU223,酶活分别为383.65、400.74、327.15、347.16、378.98IU/ml,比出发菌株B.N.K分别提高了67.1%、74.5%、42.5%、51.2%和65.0%。

Taking Bacillus subtilis natto B.N.K as initial strain, under the optimum conditions of formation and regeneration, the protoplast of the strain was prepared. The regenerative mutants from the protoplasts with UV mutagenic treatment were screened for strains of high nattokinase activity. After repetition of UV mutation, screening and gene stability assay of mutants, five strains, DU115, DU120, DU212 and DU223 were finally obtained. Their enzyme activity were 383.65, 400.74, 327.15, 347.16, 378,98 IU/ml respectively, separately increased by 67.1%, 74.5%, 42.5%, 51.2% and 65.0% respectively.