RNAi沉默lovF基因实现土曲霉一步法发酵生产辛伐他汀

One-step fermentation for producing simvastatin via RNAi silencing of lovF gene in Aspergillus terreus

摘要:

辛伐他汀是重要的降胆固醇处方药物。莫那可林J是辛伐他汀合成过程的关键中间体，也是洛伐他汀生物合成的中间产物。为获得莫那可林J并通过一步法发酵生成辛伐他汀，构建了洛伐他汀生物合成关键基因lovF基因的RNAi载体pMHJ137，通过农杆菌介导的方法转化土曲霉F001，筛选整合到染色体的阳性菌，并在阳性菌株MJ1-24的发酵过程中加入了DMB-S-MMP验证其直接合成辛伐他汀的效率。结果显示MJ1-24不再产生洛伐他汀，产物中仅有莫那可林J累积。如果在发酵过程中加入前体物质，可得到产物辛伐他汀。综上，RNAi技术能够有效实现土曲霉基因沉默。此项技术推进了一步法发酵生产辛伐他汀的工艺开发。

Abstract:

Simvastatin is one of the important prescription drugs for hypercholesterolemia. Monacolin J is a key intermediate during simvastatin synthesis, and also an intermediate of lovastatin biosynthesis. In this work, we construct a monacolin J producing strain via RNA interference to achieve one-step fermentation to obtain simvastatin. The lovF gene silencing plasmid pMHJ137 was constructed and transformed into Aspergillus terreus by Agrobacterium tumefaciens mediated transformation method. Precursor DMB-S-MMP was supplied during the fermentation to screen positive strains of transformants; which also further confirmed the simvastatin producing capability of MJ1-24 by one-step fermentation. Strain MJ1-24 produced monacolin J rather than lovastatin, and the feeding of DMB-S-MMP resulted in the generation of simvastatin. This study suggested that RNAi can efficiently silence the lovF gene of A. terreus and promote the simvastatin production by one-step fermentation.