强启动子Psod对谷氨酸棒状杆菌pyc基因表达的影响

The Impact of Strong Promoter Psod on Pyc Gene Expression in Corynebacterium glutamicum

摘要: 为了获得L-苹果酸高产的谷氨酸棒状杆菌(C.glutamicum)，通过基因编辑，在草酰乙酸回补途径的关键酶丙酮酸羧化酶基因(pyc)前面，敲入超氧化物歧化酶基因启动子(Psod)，重组菌株命名为CZM03，通过强启动子Psod增强PYC酶活性，促进丙酮酸→草酰乙酸→苹果酸，利于苹果酸的生成。结果表明：与野生型C.glutamicum相比，重组菌株CZM03的PYC活性上调了约2.2倍；到平台期，两者的生长速率和最大生物量没有显著差异。这表明Psod强启动子的敲入，对菌的生长没有明显影响，但是PYC的酶活却有大幅度提高，这对于目的产物的积累是有利的。

Abstract: In order to obtain a strain with high yield of L-malic acid, the wild-type C. glutamicum was mod-ified with gene editing. The superoxide dismutase gene promoter (Psod) was inserted ahead of pyruvate carboxylase gene (pyc), a key gene in the oxaloacetate anaplerotic reaction, to promote the yield of L-malic acid in a flow of pyruvate to oxaloacetate, then to L-malic acid. This strain was named as CZM03. The experimental results showed that the PYC activity was upregulated about 2.2-fold in CZM03 compared with the wild-type C. glutamicum. There was no significant difference in the growth rate and the maximum biomass at the plateau stage between the two strains. This indicates that the knock-in of the Psod promoter had no significant effect on the growth of the bacteria, but the activity of PYC increased significantly, which was beneficial to the accumulation of the target products.