蛋白酶产生菌的筛选和紫外诱变育种

Screening and UV Mutagenesis of Protease Producing Strains

目的:筛选水产品加工用蛋白酶产生菌,为酶的的分子改造和水产品加工提供材料基础。方法:通过在富含水产品蛋白的场所的针对性采样,菌落平板筛选结合发酵上清液平板验证以及Folin-酚试剂定量检测确认筛选结果,并通过紫外诱变提高产中性蛋白酶菌株的产酶能力。结果:从12份土样中分离187株具有明显蛋白酶活性的单菌落。在挑取的11株透明圈明显的蛋白酶产生菌中,菌株W9在所有菌株中可以稳定产生较高的蛋白酶酶活力,约为1 594U/ml。通过对其进行紫外诱变后,在突变株中筛选得到一株酶活约为1 845U/ml的W9UV突变株,比野生菌株酶活提高了15.6%。结论:突变菌株W9UV可稳定产生较高的蛋白酶酶活力,发酵性能优良。

Objective：To obtain high and well defined protease-producing strains.These strains can be used in seafood process to produce poly-peptide.Method：The protease-producing strains were first screen from soil by well-designed sampling sites and colony screening,fermentation supernatant identification and Folin-phenol measurement assay etc.To improve the production of protease capability for the target strain,UV mutagenesis were further introduced.Result：187 protease-production strains were screened from the collected 12 soil samples.Further secondary screening indicated a strain W9 produced stably higher enzyme activity than any other strains among the primary screened 11 strains.The activity of strain W9 reached to 1 594U/ml.Mutant strain W9UV was obtained by UV mutagenesis which enhances the protease activity by 15.6% in comparison with that of the wild strain W9,with the activity of 1845 U/ml.Conclusion：W9UV strain has a greater protease activity and more stably fermentation performance.