吸水链霉菌HS023 milF基因敲除构建产5-酮米尔贝霉素基因工程菌

Construction of genetically engineered strain producing 5-oxomilbemycin by knocking out milF in Steptomyces hygroscopicus HS023

摘要:

摘要:【目的】通过敲除吸水链霉菌HS023的milF基因，构建产5-酮米尔贝霉素的基因工程菌。【方法】构建milF基因敲除质粒pMSST-ΔmilF，转入米尔贝霉素产生菌———吸水链霉菌HS023，获得milF基因敲除的双交换突变株F2-18。【结果】发酵结果表明:milF基因敲除突变株F2-18不再产生米尔贝霉素，仅产生中间产物5-酮米尔贝霉素，且发酵单位较出发菌株略有提升。【结论】通过敲除milF基因，发酵可生产5-酮米尔贝霉素，并直接用于驱虫药米尔贝肟和乐平霉素的化学合成，可大大简化从米尔贝霉素到米尔贝肟和乐平霉素的合成步骤。

Abstract:

Abstract:［Objective］ To construct a 5-oxomilbemycin producing strain by knocking out milF gene in Streptomyces hygroscopicus HS023． ［Methods］Plasmid pMSST-ΔmilF was constructed and introduced into milbemycin industrial strain Streptomyces hygroscopicus HS023，and milF mutant F2-18 was selected by PCR amplification．［Results］Fermentation experiments showed that no milbemycins was produced in F2-18，but 5-ketomilbemycin，the intermediate of milbemycin，was obviously accumulated，and the fermentation titer was enhanced．［Conclusion］ Genetically engineered strain can simplify the synthesis of milbemycin oxime and lepimectin chemical from milbemycin．