常压室温等离子体-紫外复合诱变选育新硫肽类抗生素166A高产菌株

摘要：目的 通过对新硫肽类抗生素166A产生菌小单孢菌TMD166进行诱变选育研究，以期获得产166A的高产菌株。方法 使用多功能等离子体诱变系统(multifunctional plasma mutagenesis system, MPMS)对出发菌株TMD166的孢子进行等离子体-紫外(MPMS-UV)复合诱变，单孢子悬液经照射处理、涂布培养后获得单菌落，并以牛津杯固体发酵高通量筛选方法对菌株进行初筛，之后对高产菌株进行摇瓶复筛，利用突变株摇瓶发酵的化学效价筛选出正突变菌株。结果 对比MPMS-UV不同诱变剂量发现，MPMS105s-UV60s复合诱变剂量获得的正突变率最高，达到41.43%，相应致死率为99.88%。最终筛选出一株166A高产突变株TMD166-MU1，在培养温度为28℃、210 r/min的条件下，经过96~120 h培养后，166A产量相比出发菌株提高了7.47倍。结论 采用MPMS-UV复合诱变方式，再结合牛津杯固体发酵高通量筛选方法和摇瓶复筛，可高效筛选获得166A高产菌株。

Breeding of new thiopeptide antibiotic 166A high-yield producing strain by MPMS composite mutagenesis with plasma and UV

Abstract Objective To obtain the new thiopeptide antibiotics 166A high-yield producing strain by meansof mutation breeding of TMD166 strain. Methods The spores from the original strain were treated by Plasma andUV composite mutation in multifunctional plasma mutagenesis system (MPMS). The strain spore suspension ofTMD166 treated under different mutagenesis conditions was spread on the cultural medium plates to obtain a singlecolony. Through the first high throughput screening with the oxford cup method and the following second screeningwith the flask fermentation culture, positive mutant strains were screened out by comparison of the fermentation titer.Results MPMS105s-UV60 composite mutagenesis can obtain the highest positive mutation rate among differentMPMS-UV mutation conditions. Its positive mutation rate and lethality rate were 41.43% and 99.88%, respectively.After multiple conditions of MPMS or/and UV mutagenesis, a mutant strain coded as TMD166-MU1 was finallyscreened out and the yield of 166A was 7.47 times higher than that of the original strain after being cultured in theshaker at 210 r/min under 28℃ for 96~120 h. Conclusion The MPMS-UV composite mutagenesis with oxford cuphigh throughput screening can significantly improve efficiency to screen out high-yield