出发菌株经紫外照射诱变后,再采用激光复合诱变方式进行的筛选,并对其传代稳定性进行研究,以期进一步获得稳产高产那西肽产生菌突变株。结果表明紫外照射100 s得到的NXT-U19放瓶效价比出发菌株(546.17μg/mL)提高了44.22%,达到了787.71μg/mL。激光-紫外复合诱变后筛选出6株产量较高的菌株,其中以NXT-U19-J2效价最高,比原始菌株提高了65.74%,达到了905.22μg/mL。经传代培养分析,NXT-U19-J2诱变株的遗传稳定性较好,该结果表明,激光复合诱变是获得高产那西肽产生菌的有效途径。

The starting strain was treated by ultraviolet irradiation,then it was screened further by laser compound mutation and studied on the genetic stability to obtain the stable high-yield nosiheptide-producing strains.The result showed that the potency of strain NXT-U19 was increased by 44.22% compared to the original strain(546.17 μg/mL),reaching 787.71 μg/mL.Six high-yield strains was screened by laser-ultraviolet compound mutation,among them the highest potency of strain NXT-U19-J2 was increased by 65.74% compared to the original strain,reaching 905.22 μg/mL.The analysis of subculture proved that the genetic stability of mutated strain NXT-U19-J2 was good.This result has showed that laser compound mutation is the efficient method to obtain the high-yield nosiheptide-producing strains.