紫外诱变原生质体选育溶菌酶高产菌株的研究

Breeding of a high lysozyme producingBacillusstrain by mutagenesis of protoplasts

中文摘要:

      以1株产海洋溶菌酶活性较高的菌株（S-12-86）为原始菌株，对其原生质体的制备、再生及紫外诱变育种进行了研究。实验所确定的原生质体的最佳制备条件为:菌株S-12-86培养18 h，溶菌酶浓度为1.0 mg/ml，在35 ℃下，酶解30 min，原生质体形成率为97.6%，再生率为23.6%。同时实验所确定的原生质体诱变的适宜条件为:30 W紫外灯下80 cm照射120 s。对大量再生突变株进行筛选，最终获得了1株遗传性能稳定的菌株R-J-101，其产酶活力达到1 808 U/mg，比原始菌株（1 290 U/mg）提高了40％。

英文摘要:

      The preparation, regeneration and UV mutagenesis of protoplasts of strain S-12-86, which had high lysozyme producing activity, were studied. The results showed that the optimal conditions of the preparation and regeneration of protoplast were as follows: incubation time of the strain S 12 86 was 18 h, concentrations of lysozyme was 1.0 mg/ml, and time of enzymolysis was 30 min at 35 ℃. The rates of formation and regeneration of protoplast under the optimal conditions were 97.6% and 23.6%, respectively. The optimal condition for mutagenesis of protoplasts was achieved when the protoplasts of strain S-12-86 were irradiated by a 30 w UV lamp at an 80 cm distance for 120 s. After being selected from a large amount of the regenerative mutants, a genetically stable mutant strain R-J-101, of which enzyme activity was 40% higher than that of the original strain S-12-86, was obtained under specific mutation conditions.