乳糖代替IPTG诱导己糖激酶在大肠杆菌中的表达

摘要

The expression strain BL21 (DE3)/pET-glk was constructed and the feasibility of expression of GLK in recombinant E. coli BL21(DE3) induced by lactose instead of IPTG was tested. The results indicaded that the optimal induction method was to add 10 g/L (final concentration) lactose at the mid-log-phase of cell growth (OD600≈l.0) and incubate at 25 ℃ for 6 h. Under this condition the production of GLK enzyme induced by lactose was about 30.45 ％ of the bacterial total protein which was not significantly different from that induced by IPTG(≈31.12％). The final biomass induced by lactose was higher than that induced by IPTG. This result suggested that the lactose instead of IPTG for T7 promoter induction should be easily scaled up for industrial production of recombinant protein with lower cost.%构建了己糖激酶GLK高效表达的工程菌株BL21(DE3)/pET-glk,考察了乳糖代替IPTC诱导己糖激酶GLK在大肠杆菌BL21(DE3)中表达的可行性.实验结果表明,工程菌对数生长中期(OD<,600>约为1.0)添加终浓度为10 g/L的乳糖于25℃的条件下诱导6 h能获得最大量的目的蛋白和菌体量,目的蛋白表达量占总蛋白的30.45%,与IPTG诱导条件下的31.12%无明显差异.同时,乳糖诱导后收获的菌体量高于IPTG诱导,显示出了乳糖同样是一种T7启动子的廉价高效诱导荆,可以代替昂贵的IPTG用于己糖激酶GLK的规模化发酵,也为其他重组蛋白的生产提供了有益的参考和借鉴.