[ Objective]The purpose of this project was to study L - serine production rate and the fermentation efficiency affected by the expression of GDH. [Method] The gdh (glutamate dehydrogenase) gene was cloned from Corynebacterium glutamicum ATCC39135 and amplified by PCR. The gdh gene was inserted into E. Coli - Brevibacterium flavum shuttle expression vector pEC7 to construct a recombinant plasmid pEC7G, which was subsequently transformed into B. Flavum C - 11, producing a genetic engineering strain C - 11G. [ Result] It was shown that the GDH enzyme activity could be increased by 32.1% in the strain C - 11G, and the producing acid rate of L - serine was 15. 28 G/L, which was 33.80% higher than the host strain. [ Conclusion ] The engineering strain C - 11G was successful constructed. The expression of gdh gene has a higher activity than the host strain, and can promote L-serines production.%[目的]研究谷氨酸脱氢酶的表达对L-丝氨酸产率及发酵效率的影响.[方法]从谷氨酸棒杆菌模式菌株C.glutamicum ATCC39135中克隆出gdh基因,以大肠杆菌-黄色短杆菌穿梭表达载体pEC7为基础,构建重组质粒pEC7G,并转化黄色短杆菌B.flavum C -11,获得重组菌株C-11G.[结果]重组菌株C-11G的GDH酶活力提高32.7％,产酸率为15.28 g/L,比原宿主菌提高了33.80％.[结论]成功构建重组菌株C-11G,所克隆的gdh基因有较高表达活性,并对L-丝氨酸产量的提高有促进作用.
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