Method for Producing Substance Utilizing Microorganism

Abstract

In a method for producing a target substance utilizing a microorganism comprising culturing the microorganism in a medium to produce and accumulate the target substance in the medium and collecting the target substance, microorganism is employed, which is a mutant strain or a genetic recombinant strain constructed from a parent strain of the microorganism having a respiratory chain pathway of high energy efficiency and a respiratory chain pathway of low energy efficiency as respiratory chain pathways, and having either one or both of the following characteristics: (A) the respiratory chain pathway of high energy efficiency is enhanced, (B) the respiratory chain pathway of low energy efficiency is deficient.

What is claimed is: 
     
         1 . A method for producing a target substance utilizing a microorganism comprising the steps of:
 A) culturing the microorganism in a medium so that the target substance is produced and accumulates in the medium, and   B) collecting the target substance;   wherein the microorganism is constructed from a parent strain of the microorganism having a respiratory chain pathway of high energy efficiency and a respiratory chain pathway of low energy efficiency as respiratory chain pathways, and the microorganism is a mutant strain or a genetic recombinant strain having either one or both of the following characteristics:   (A) the respiratory chain pathway of high energy efficiency is enhanced,   (B) the respiratory chain pathway of low energy efficiency is deficient.   
     
     
         2 . The method for producing a target substance according to  claim 1 , wherein the respiratory chain pathway of high energy efficiency is enhanced by increasing a copy number of a gene coding for an enzyme involved in the respiratory chain or modification of an expression regulatory sequence of the gene. 
     
     
         3 . The method for producing a target substance according to  claim 1 , wherein the respiratory chain pathway of low energy efficiency is made deficient by disruption of a gene coding for an enzyme involved in the respiratory chain. 
     
     
         4 . The method for producing a target substance according to  claim 1 , wherein enzymes of the respiratory chain of high energy efficiency comprise SoxM type oxidase, bc1 complex, NDH-1, or combinations thereof. 
     
     
         5 . The method for producing a target substance according to  claim 1 , wherein enzymes of the respiratory chain of low energy efficiency comprise cytochrome bd type oxidase, NDH-II, or combinations thereof. 
     
     
         6 . The method for producing a target substance according to  claim 1 , wherein activity of SoxM type oxidase is enhanced and NDH-II is made deficient in the microorganism. 
     
     
         7 . The method for producing a target substance according to  claim 1 , wherein the SoxM type oxidase is cytochrome bo type oxidase. 
     
     
         8 . The method for producing a target substance according to  claim 1 , wherein the microorganism is selected from the group consisting of bacterium belonging to the genus  Escherichia  and coryneform bacterium. 
     
     
         9 . The method for producing a target substance according to  claim 1 , wherein the target substance is selected from the group consisting of L-amino acids and nucleic acids.