Tianjin University of Science and Technology

Chenglin Zhang

Yanjun Li

Qingyang Xu

Hao Xu

Ning Chen

Xiaoguang Fan

Xixian Xie

Heyun Wu

Qian Ma

Qiang Li

Yu Zhang

Xierong Dong

Guoliang Li

Shibao Han

Zishen Wang

Nan Lu

Yingzi Li

Ziyi Li

Fuzhou Zhu

The invention relates to a 2-isopropyl malate synthase, a genetically engineered bacterium for producing L-leucine and application thereof and belongs to the field of metabolic engineering. The genetically engineered bacterium is obtained by overexpressing an isopropyl malate synthase coding gene leuAfor relieving feedback inhibition by L-leucine, an acetohydroxy acid synthase coding gene ilvBNfor relieving feedback inhibition by L-isoleucine, a 3-isopropyl malate dehydrogenase coding gene leuB and a 3-isopropyl malate dehydratase coding gene leuCD in host cells. The genetically engineered bacterium for producing the L-leucine is free from nutritional deficiency, rapid in growth, short in fermentation period, high in yield and high in conversion rate.

2-isopropylmalate synthetase and engineering bacteria and application thereof

The present disclosure relates to a genetically engineered strain with high production of uridine and its construction method and application. The strain was constructed as follows: heterologously expressing pyrimidine nucleoside operon sequence pyrBCAKDFE (SEQ ID NO:1) on the genome ofprompted by strong promoter Pto reconstruct the pathway of uridine synthesis; overexpressing the autologous prsA gene coding PRPP synthase by integration of another copy of prsA gene promoted by strong promoter Pon the genome; deficiency of uridine kinase, uridine phosphorylase, ribonucleoside hydrolase, homoserine dehydrogenase I and ornithine carbamoyltransferase. When the bacteria was used for producing uridine, 40-67 g/L uridine could be obtained in a 5 L fermentor after fermentation for 40-70 h using the technical scheme provided by the disclosure with the maximum productivity of 0.15-0.25 g uridine/g glucose and 1.5 g/L/h respectively which is the highest level of fermentative producing uridine reported at present.

Genetically engineered bacterium used for producing uridine with high-yield

Growing community of inventors

Tianjin, China

Chenglin Zhang