谷氨酸棒杆菌H+-ATPase基因失活提高谷氨酸产生量

为了证实在谷氨酸棒杆菌中,利用H⁺-ATPase基因失活构建高产谷氨酸基因工程菌的应用可行性,通过重组PCR技术部分缺失H⁺-ATPaseγ亚基基因序列,采用插入失活方法构建H⁺-ATPase失活的谷氨酸棒杆菌。考察了其谷氨酸产生能力及对生长速率的影响。实验结果表明,H⁺-ATPase失活的谷氨酸棒杆菌在含有100g/L的葡萄糖培养基中摇瓶发酵,其谷氨酸最大累积量为51.6g/L, 比野生菌株提高了42.9%。生长速率研究结果表明,H⁺-ATPase失活的谷氨酸棒杆菌生长速率略低于野生谷氨酸棒杆菌。证实了H⁺-ATPase基因失活对提高谷氨酸产量的作用,为利用H⁺-ATPase基因构建高产谷氨酸基因工程菌株提供了科学依据。

Overproduction of Glutamic Acid in Corynebacterium glutamicum with H+ -atp Inactivation

In order to confirm the application feasibility of overproduction of glutamic acid in C. glutamicum with H⁺-ATP inactivation in the construction of genetically modified bacteria. The sequence encoding H⁺-ATPase γ subunit in C.glutamicum ATCC13032 was partially deleted by crossover PCR, and the mutant, in which H⁺-atp gene was inactivated, was obtained by insertion inactivation. The glutamic acid production and growth rate of the mutant were tested. The results showed that the maximum production of glutamic acid of the mutant was 51.6 g/L in 100 g/L glucose culture medium, with 42.9 % increase in contrast to the wild parent strain, and that growth rate of the mutant in measurement of the growth curves was lower than wild parent strain. The results suggest that H⁺-atp gene inactivated in C.glutamicum increases glutamic acid production, and slightly reduces growth rate of the bacteria.