Method for producing an organic acid

A method for producing succinic acid comprising:

• A) allowing a substance to act on an organic raw material in a reaction mixture containing carbonate ions, bicarbonate ions, or carbon dioxide gas, wherein the substance is selected from the group consisting of:
• i) a bacterium which has an ability to produce an organic acid and has been modified to have enhanced expression of the yidE gene,
• ii) a product obtained by processing the bacterium of i),
• iii) combinations thereof, and
• B) collecting the succinic acid:
• wherein the yidE gene is selected from the group consisting of:
• (a) a DNA comprising the nucleotide sequence of SEQ ID NO:
• 46, and
• (b) a DNA which hybridizes with a DNA comprising a nucleotide sequence complementary to the entire nucleotide sequence of SEQ ID NO:
• 46 under stringent conditions comprising washing with 1×SSC, 0.1% SDS at 60° C., and said DNA improves the ability of the bacterium to produce an organic acid when expression of the DNA is enhanced in the bacterium;
• wherein the enhanced expression is obtained by a method selected from the group consisting of:
• i) increasing the copy number of the yidE gene,
• ii) replacing a promoter sequence of the yidE gene with a stronger promoter, and
• iii) combinations thereof.