大肠杆菌副产物合成途径删除提高外源蛋白表达水平

大肠杆菌是应用最广泛的外源基因表达宿主。为探索阻断副产物产生途径对提高大肠杆菌表达外源蛋白的能力,本实验以野生型大肠杆菌菌株为基础,删除其乳酸脱氢酶基因(ldhA),磷酸烯醇式丙酮酸合成酶基因(pps)和丙酮酸甲酸裂解酶基因(pflB)。在此基础上,以甘露聚糖酶基因man为报告基因,考察阻断以上代谢途径对大肠杆菌产酶能力的影响。结果显示,以上述三个基因叠加删除的三重突变株为宿主时,重组茵产酶水平最高,比酶活达到158.3 U/mg,相比野生出发菌株提高82.3%。

Elimination of byproduct synthesis in Escherichia coil to improve recombinant protein production

Escherichia coli was one of the most common hosts for recombinant protein production. In this study, multiplegene deletions with mutation in D-lactate dehydrogenase （ldhA）, phosphoenolpyruvate synthase （pps）, pyruvate formate lyase （pflB）, were tested for their effects on recombinant protein productivity in E. coli, and a mannanase gene （man） was used as the reporter gene. As a result, the CICIM B0013 -003 was obtained from deletions of all three genes in E. coli CICIM B0013 and its activity was as high as 158.3 U/mg, which was increased by 82.3 % if compared with that of the wild strain.