摘要
通过对产普鲁兰酶的重组大肠杆菌E.coli BL21(DE3)/p ET28a-s-pul菌株在发酵过程中质粒稳定性和普鲁兰酶生成量的考察,发现不同宿主对质粒稳定性及酶活性有重要影响。本文利用E.coli BL21(DE3)p Lys S菌株为宿主,构建重组菌E.coli BL21(DE3)p Lys S/p ET28a-s-pul,通过控制外源蛋白的本底表达,提高了重组菌株的质粒稳定性。优化发酵培养基和发酵条件以后,重组菌产普鲁兰酶能力由480 U/m L提高至627 U/m L,增幅为30.6%。研究结果认为,严格控制外源蛋白的本底表达,是改善重组菌稳定性的重要方法之一。
It was found that different host bacteria would seriously affect the plasmid stability and pullulanase activity by investigating the recombinant E. coli BL21 （DE3）/pET28a-s-pul producing pullulanase. In this study,a recombinant E. coli BL21（DE3）pLysS/pET28a-s-pul was constructed with a new strain named E. coli BL21（DE3）pLysS,which suc-cessfully controlled the basal expression and improved the plasmid stability. After optimizing the medium and fermentation conditions,the pullulanase activity was enhanced from 480 U/mL to 627 U/mL with an increase of 30. 6%. The results of this research illustrated that strictly controlling the basal expression of the foreign protein was one of the important methods to improve the stability of recombinant bacteria.
出处
《工业微生物》
CAS
CSCD
2015年第2期13-20,共8页
Industrial Microbiology
基金
国家高技术研究发展计划(863计划)
食品酶及应用(2012AA022207)
江苏高校优势学科建设工程资助项目
关键词
普鲁兰酶
大肠杆菌
质粒稳定性
本底表达
发酵优化
pullulanase
E. coli
plasmid stability
basal expression
fermentation optimization
