基因重组法构建表柔红霉素高产菌株

Construction of a high epidaunorubicin-producing strain by gene recombination

表柔红霉素是抗肿瘤药表阿霉素的半合成前体。通过中断dnmV基因,并将酮基还原酶aveBⅥ基因导入,可以将柔红霉素产生菌改造成表柔红霉素产生菌。本研究通过此方法得到了产表柔红霉素的基因工程菌mHJ-02-30-1,在此基础上构建柔红霉素生物合成基因dnrU的同框敲除质粒pYG1116,将其转入原有的表柔红霉素产生菌mHJ-02-30-1,通过同源重组双交换的方法,将dnrU基因内部编码153个氨基酸的序列敲除。从而得到dnrU基因失活的突变株mYG1116E,发酵验证表明该突变株表柔红霉素发酵单位比出发菌株提高了约40%。

4＇-Epidaunorubicin is major precursor for the semisynthesis of epidoxorubicin, a clinically important antitumor antibiotic. By means of homologous recombination used for dnmV replacement and aveB IV integration into daunorubicin-producing strain, a mutant strain, named mHJ-02-30-1, was obtained that produces 4＇-epi- daunorubin. An in-frame knock-out plasmid was transformed into mHJ-02-30-1 to delete the dnrU gene fragment encoding 153 amino acids. The genetic engineering strain mYG1116E, a dnrU gene inactivation mutant, was con- structed by homologous recombination, which increased the 4＇-epidaunorubin production by 40% compared with the original strain.