大肠杆菌ptsG突变体中半乳糖通透酶和丙酮酸羧化酶的表达提高了厌氧条件下的生长速率和琥珀酸产量。
Expression of galactose permease and pyruvate carboxylase in Escherichia coli ptsG mutant increases the growth rate and succinate yield under anaerobic conditions.
作者信息
Wang Qingzhao, Wu Chanyuan, Chen Tao, Chen Xun, Zhao Xueming
机构信息
Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, PR China.
出版信息
Biotechnol Lett. 2006 Jan;28(2):89-93. doi: 10.1007/s10529-005-4952-2.
In Escherichia coli, disruption of ptsG, which encodes the glucose-specific permease of the phosphotransferase transport system (PTS) protein EIICB(Glc), is crucial for high succinate production. This mutation can, however, cause very slow growth and low glucose consumption rates. The ptsG mutant (TUQ2), from wild type E. coli W1485, and E. coli galP (encoding galactose permease) and glk (encoding glucose kinase) gene expression plasmids were constructed. TUQ2 increased the generation time to approximately 4 h and gave a higher final cell density of 0.5 g/l by expression of galP. However, glk expression had no effect on the mutant. After expression of pyruvate carboxylase (PYC) and galactose permease, the ptsG mutant showed higher succinate yield (1.2 mol/mol glucose) and the specific rate of glucose consumption from 0.33 to 0.6 g/1 h.
在大肠杆菌中，编码磷酸转移酶运输系统（PTS）蛋白EIICB（Glc）的葡萄糖特异性通透酶的ptsG基因的破坏，对于高琥珀酸产量至关重要。然而，这种突变会导致生长非常缓慢且葡萄糖消耗率较低。构建了来自野生型大肠杆菌W1485的ptsG突变体（TUQ2），以及大肠杆菌galP（编码半乳糖通透酶）和glk（编码葡萄糖激酶）基因表达质粒。通过表达galP，TUQ2将代时延长至约4小时，并使最终细胞密度提高到0.5 g/l。然而，glk的表达对该突变体没有影响。在表达丙酮酸羧化酶（PYC）和半乳糖通透酶后，ptsG突变体显示出更高的琥珀酸产量（1.2 mol/mol葡萄糖），葡萄糖消耗的比速率从0.33提高到0.6 g/1 h。
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