Chinese Academy of Sciences

Ningxia Eppen Biotech Co., Ltd

Tingyi Wen

Yun Zhang

Shuwen Liu

Xiuling Shang

Yong Fang Liang

Yu Zhang

Qian Jack Liu

Guoqiang Zhang

Jiyin Ma

Gang Meng

Aiying Wei

Jifu Wen

Aihua Deng

Haihan Xiao

Rui Ren

Jinlong Chen

Xiaowei Guo

Lipeng Yang

Chunguang Zhao

Qian Liu

The present invention discloses a method for modifying an amino acid attenuator, a class of amino acid attenuator mutants, engineered bacteria created on the basis of the amino acid attenuator mutants, and use of the engineered bacteria. The present invention protects a method for relieving the attenuation regulation of an amino acid operon gene, which is modification of the amino acid operon gene by: removing a gene coding for a leader peptide and an anterior reverse complementary palindromic sequence in the terminator stem-loop structure, and maintaining a posterior reverse complementary palindromic sequence in the terminator. The amino acid operon particularly can be histidine operon, tryptophan operon, phenylalanine operon, alanine operon, threonine operon and etc. The present invention can be used for the production of amino acids and derivatives thereof in fermentation by bacteria, providing a novel method for improving the production of amino acids in fermentation.

Method for modifying amino acid attenuator and use of same in production

The present invention discloses anengineering bacteria producing 1,5pentanediamine through a whole cell catalysis and its application. The engineering bacteria according to the present invention, is() strain B or its derivative strains with the overexpression of a lysine decarboxylase gene and a proper expression of a lysinecadaverine antiporter gene cadB. The engineering bacteria according to the present invention is the engineering bacteria producing 1,5pentanediamine through the whole cell catalysis constructed fromB derivative strains, which has an overexpression of a lysine decarboxylase gene cadA and a proper expression of the lysinecadaverine antiporter gene cadB; The present invention further discloses a method of producing a 1,5pentanediamine catalyzed by the engineering bacteria, the yield and production intensity of 1,5pentanediamine in biobased production could be significantly improved through the method, hence it could be applied to mass production and convenient for extending applications.

[object Object]

The present invention relates to recombinant bacteria producing L-amino acid, in which the recombinant bacteria has reduced expression of the glucose-6-phosphate isomerase gene pgi and improved expression of the glucose-6-phosphate dehydrogenase gene -opcA than the starting bacteria, where the starting bacterium is a bacterial strain that can accumulate target amino acid(s) and preferably, the amino acid is L-histidine.

Recombinant strain producing L-amino acids, constructing method therefor and method for producing L-amino acids

Disclosed is a method for introducing an exogenous DNA by overcoming the restriction modification barrier of the target bacterium. The method includes the steps of 1) co-expressing all DNA-methyltransferase-encoding genes in the genome of the target bacterium inin which the restriction modification system thereof has been deleted to obtain a recombinant bacterium A, 2) introducing an exogenous DNA molecule into the recombinant bacterium A for in vivo modification so as to obtain a methylation-modified exogenous DNA molecule, and 3) introducing the methylation-modified exogenous DNA molecule into the target bacterium.

Method for introducing an exogenous DNA by overcoming the restriction modification barrier of a target bacterium

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Beijing, China

Tingyi Wen