crtE、crtY、crtI、crtB基因共调控提高β-胡萝卜素产量

Co-regulation of crtE,crtY,crtI,crtB gene expression to improve β-carotene yield

代谢合成途径优化的关键在于途径中多个基因表达的调控,本研究使用不同强度启动子对代谢通路中多个相关基因同时调控以提高大肠杆菌β-胡萝卜素产量。将来源于P.agglomerans的4个基因crtE、crtY、crtI、crtB,通过Golden Gate DNA方法与不同强度启动子组合得到质粒库,并转化到底盘细胞中进行颜色筛选。筛选得到crtE、crtY、crtI、crtB启动子组合各不相同的菌株,β-胡萝卜素产量在0.64-8.82mg/g,最高产量比对照提高了65.2%。本研究验证了通过Golden Gate组装建库对代谢通路多个基因同时调控以提高目的产物产量的可行性。

The key of metabolic or biosynthetic pathway optimization depended on expression regulation of genes in the pathway. Expression of β-carotene synthetic pathway genes were simultaneously modulated by promoters of various strength to optimized the efficiency of the pathway. Genes of crtE, crtY, crtI, crtB from P. agglomerans were modulated by promoter library and enabled by Golden Gate DNA assembly method to construct plasmid library, then transferred to E. coli chassis. Representative strains were obtained from the library and proved to have different expression pattern of crtE, crtY, crtI and crtB, and different Q-carotene yield in the range of 0.64- 8.82 mg/g. The highest yield was increased by 65.2% compared to the control strain. It is proved that simultaneous regulation of multiple genes in the metabolic pathway by constructing library with Golden Gate DNA assembling method to improve target production.