【摘要】 采用紫外线诱变和60Co-γ射线协同诱变的方法,对出发菌株Uco-3的原生质体进行诱变处理,通过正突变率与诱变剂量的相互关系,确定最佳诱变剂量。采用4min的紫外线照射和剂量为500Gy的γ射线对黑曲霉Uco-3的原生质体进行诱变,获得一株产高温乳糖酶的高产突变株,突变株产乳糖酶能力显著提高,产酶活力达44.37U/mL,是出发菌株Uco-3的2.73倍。更多还原

【Abstract】 The protoplasts of original Aspergillus niger strain Uco-3 were treated with the cooperation of UV and γ-ray to obtain the high-yielding strain producing the thermostable β-galactosidase. Under the optimum conditions of formation and regeneration protoplasts were prepared. According to the interaction of positive mutation rate and radiation dose,the optimum condition was determined. The optimum dose of UV was 4 minutes and the optimum dose of γ-ray was 500 Gy. After mutagenetic treatment of protoplasts and selection from a lot of mutants,a mutant DL116 producing the thermostable β-galactosidase was obtained. The β-galactosidase activity of DL116 was increased from 16.27 U/mL to 44.37 U/mL,which was higher than that of strain Uco-3.更多还原