Method for producing a target substance by fermentation

#1. Technical Field

#The present invention relates to a method for producing a target substance by using a microorganism. More precisely, the present invention describes a method to improve production using a microorganism of final target products, such as L-amino acids, nucleic acids, and so forth.

#2. Background Art

#FIG. 1 shows growth curves of the pTWV229+pMW219-ΔPlac/MG1655 strain (●) and the glvA+glvC/MG1655 strain (▴) in the M9-iMal(0.2%) medium.

#FIG. 2 shows growth curves of the pTWV229+pMW219-ΔPlac/MG1655 strain (●) and the glvA+glvC/MG1655 strain (●) in the M9-Glc(0.02%)-iMal(0.18%).

#The target substance produced by a microorganism can be an L-amino acid or a nucleic acid. The “L-amino acid” is not particularly limited, so long as it is an L-amino acid that can accumulate in the medium during fermentation of a microorganism. Although the type of L-amino acid is not particularly limited, examples include basic amino acids such as L-lysine, L-ornithine, L-arginine, L-histidine and L-citrulline; aliphatic amino acids such as L-isoleucine, L-alanine, L-valine, L-leucine and glycine; amino acids which are hydroxy-monoaminocarboxylic acids such as L-threonine and L-serine; cyclic amino acids such as L-proline; aromatic amino acids such as L-phenylalanine, L-tyrosine and L-tryptophan; sulfur-containing amino acids such as L-cysteine, L-cystine and L-methionine; acidic amino acids and acid amides thereof such as L-glutamic acid, L-asparatic acid, L-glutamine and L-asparagine.

#The microorganism can have the ability to produce two or more types of amino acids.

#The L-amino acid can be a free L-amino acid, or can be a salt of an L-amino acid, such as sulfate, hydrochloride, carbonate, ammonium salt, sodium salt, and potassium salt.