Method for producing 2-methyl-butyric acid by bacterial fermentation

A method for producing 2-methyl-butyric acid comprising:

• (i) cultivating in a culture medium a 2-methyl-butyric acid-producing bacterium belonging to the genus Escherichia to produce and accumulate 2-methyl-butyric acid in the culture medium or cells of the bacterium, or both, and
• (ii) collecting 2-methyl-butyric acid from the culture medium or the cells of the bacterium, or both,
• wherein said bacterium has been modified to attenuate expression of a gene encoding a protein having tyrosine aminotransferase activity;
• wherein said expression of the gene encoding a protein having tyrosine aminotransferase activity is attenuated due to inactivation of the gene,
• wherein said gene encoding a protein having tyrosine aminotransferase activity is a tyrB gene, and
• wherein said protein having tyrosine aminotransferase activity is selected from the group consisting of:
• (A) a protein comprising the amino acid sequence set forth in SEQ ID NO:
• 2,
• (B) a protein comprising the amino acid sequence set forth in SEQ ID NO:
• 2, comprising substitution, deletion, insertion and/or addition of 1 to 30 amino acid residues, and wherein said protein has tyrosine aminotransferase activity, and
• (C) a protein comprising an amino acid sequence having an identity of not less than 90% with respect to the entire amino acid sequence set forth in SEQ ID NO:
• 2, and wherein said protein has tyrosine aminotransferase activity.