Abstract: The invention relates to a plasmid, a DNA assembly method and its application recombinant strain. The plasmid has single adjacent Type IIP and Type IIS RE recognition sites. The plasmid combines the properties of Type IIP and Type IIS REs to achieve recursive cycling, SCAR-free and repeat sequence assembly.

Abstract: 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.

Abstract: A method for fermentation-production of a pentanediamine, comprising: culturing a cell expressing a lysine decarboxylase to obtain a whole cell fermentation broth comprising a pentanediamine; and extracting the pentanediamine from the whole cell fermentation broth, and striping the whole cell fermentation broth of carbon dioxide contained therein before adding a strong base. The method greatly increases a production volume of the pentanediamine.

Abstract: A recombinant bacterium for producing L-lysine, a construction method thereof, and a method for producing L-lysine by using the recombinant bacterium. The recombinant bacterium has increased expression and/or activity of asparaginase compared to a starting bacterium.

Abstract: The invention relates to a plasmid, a DNA assembly method and its application recombinant strain. The plasmid has single adjacent Type IIP and Type IIS RE recognition sites. The plasmid combines the properties of Type IIP and Type IIS REs to achieve recursive cycling, SCAR-free and repeat sequence assembly.

Abstract: 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.

Abstract: A method for fermentation-production of a pentanediamine, comprising: culturing a cell expressing a lysine decarboxylase to obtain a whole cell fermentation broth comprising a pentanediamine; and extracting the pentanediamine from the whole cell fermentation broth, and striping the whole cell fermentation broth of carbon dioxide contained therein before adding a strong base. The method greatly increases a production volume of the pentanediamine.

Abstract: The present invention discloses an E. coli engineering bacteria producing 1,5pentanediamine through a whole cell catalysis and its application. The engineering bacteria according to the present invention, is Escherichia coli (E. coli) strain B or its derivative strains with the overexpression of a lysine decarboxylase gene and a proper expression of a lysinecadaverine antiporter gene cadB.

Abstract: 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.

Abstract: The present invention discloses an E. coli engineering bacteria producing 1,5-pentanediamine through a whole cell catalysis and its application. The engineering bacteria according to the present invention, is Escherichia coli (E. coli) strain B or its derivative strains with the overexpression of a lysine decarboxylase gene and a proper expression of a lysine-cadaverine antiporter gene cadB. The engineering bacteria according to the present invention is the engineering bacteria producing 1,5-pentanediamine through the whole cell catalysis constructed from Escherichia coli B derivative strains, which has an overexpression of a lysine decarboxylase gene cadA and a proper expression of the lysine-cadaverine antiporter gene cadB.

Abstract: 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 in E. coli in 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.

Abstract: The present application discloses recombinant bacteria producing L-amino acid(s) its construction method and the method of producing L-amino acid(s). The recombinant bacteria producing L-amino acid(s) according to the present invention has reduced expression of the glucose-6-phosphate isomerase Pgi and improved expression of the glucose-6-phosphate dehydrogenase Zwf-OpcA than the starting bacteria, wherein: said starting bacterium is a bacterial strain which can accumulate target amino acid(s). During fermenting and culturing the recombinant bacteria according to the present invention, it is observed that the effect of improving yield can be additive and the yield of L-amino acid(s) is improved obviously. The strategy of combinational modification according to the present invention develops a new method of improving the yield of L-amino acid(s) and hence it can be applied to produce L-amino acid(s) through bacterialfermentation.

Abstract: A method for producing L-lysine by fermentation comprises the steps of modifying an aconitase gene and/or regulatory element thereof in a chromosome of a bacterium so that the activity and/or the expression amount of the aconitase of the bacterium are reduced but not eliminated; and producing L-lysine by the fermentation of the modified bacterium. In addition, also provided are methods and uses derived from the method as well as bacteria used in these methods and uses.

Abstract: The present invention discloses a method for introducing an exogenous DNA by overcoming the restriction modification barrier of the target bacterium. The method provided in the present invention comprises the steps of 1) co-expressing all DNA-methyltransferase-encoding genes in the genome of the target bacterium in E. coli in 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; 3) introducing the methylation-modified exogenous DNA molecule into the target bacterium. The experiments of the invention have demonstrated that the invention has a high transformation efficiency compared to prior methods for enabling genetic manipulation by overcoming the restriction modification barrier of the bacterium.