肉桂地链霉菌接合转移体系的构建及nsdA基因中断对其次级代谢的影响

以pSET152和pHL212为出发质粒，通过供体大肠杆菌ET12567（pUZ8002）和S17-1属间接合转移肉桂地链霉菌（Streptomyces cinnamonensis），首次构建并优化了肉桂地链霉菌的接合转移系统。利用PCR介导的基因置换技术快速构建了肉桂地链霉菌nsdA基因 （negative regulator of Streptomyces differentiation）中断载体，通过接合转移导入肉桂地链霉菌工业菌株BIB2005，筛选得到一株遗传稳定表型为AmR、KmS的接合子BIB309。PCR分析结果显示该接合子即为nsdA中断突变株。与出发工业菌株相比，在摇瓶水平上nsdA中断突变株BIB309莫能菌素产能提高了2.7倍。

Construction of the Conjugal Transfer System of Streptomyces cinnamonensis and Effect of PCR-mediated nsdA Gene Disruption on Its Secondary Metabolism

Intergeneric transfer of plasmid vectors pSET152 and pHL212 from donor Escherichia coli ET12567(pUZ8002) and S17-1 to Streptomyces cinnamonensis were demonstrated and optimized. The nsdA gene disruption structure was constructed by PCR-targeting system and then introduced into S. cinnamonensis BIB2005 through intergeneric conjugal transfer. After PCR analysis, the screened AprRKanS conjugant BIB309 was confirmed to be the nsdA mutant. Compared with the start strain, the yield of monensin of the nsdA mutant BIB309 increased 270 percent in the level of flask.