Abstract: The present invention provides a method for producing 2-methyl-butyric acid by fermentation using a bacterium belonging to the order Enterobacterales which has been modified to attenuate expression of a tyrB gene encoding a protein having tyrosine aminotransferase activity. The method also allows for production of a byproduct substance of 2-methyl-butyric acid during fermentation of the Enterobacterales bacterium having 2-methyl-butyric acid-producing ability.

Abstract: The present invention describes a method for producing a useful metabolite using a bacterium of the family Enterobacteriaceae, particularly a bacterium belonging to the genus Escherichia, which has been modified to contain a gene(s) expression system including elements of the LysR-type protein-regulated transcriptional machinery modified in such a way that auto-inducible positive feedback regulation of the system is mediated by a coinducer. The method is suitable for producing branched-chain L-amino acids, particularly L-valine, L-isoleucine and L-leucine; and D-pantothenic acid.

Abstract: A mutant bacterial acetolactate synthase (AHAS I) which is resistant to feedback inhibition by L-valine is described. Also described is a method for producing branched-chain L-amino acids using a bacterium from the Enterobacteriaceae family wherein the L-amino acid productivity of said bacterium is enhanced by the use of the acetolactate synthase (AHAS I) which is resistant to feedback inhibition by L-valine. This acetolactate synthase contains a mutant small subunit encoded by the mutant ilvN gene.

Abstract: The present invention describes a method for producing a useful metabolite using a bacterium of the family Enterobacteriaceae, particularly a bacterium belonging to the genus Escherichia, which has been modified to contain a gene(s) expression system including elements of the LysR-type protein-regulated transcriptional machinery modified in such a way that auto-inducible positive feedback regulation of said system is mediated by a coinducer. The method is suitable for producing branched-chain L-amino acids, particularly L-valine, L-isoleucine and L-leucine; and D-pantothenic acid.

Abstract: A mutant bacterial acetolactate synthase (AHAS I) which is resistant to feedback inhibition by L-valine is described. Also described is a method for producing branched-chain L-amino acids using a bacterium from the Enterobacteriaceae family wherein the L-amino acid productivity of said bacterium is enhanced by the use of the acetolactate synthase (AHAS I) which is resistant to feedback inhibition by L-valine. This acetolactate synthase contains a mutant small subunit encoded by the mutant ilvN gene.

Abstract: A mutant bacterial acetolactate synthase (AHAS I) which is resistant to feedback inhibition by L-valine is described. Also described is a method for producing branched-chain L-amino acids using a bacterium from the Enterobacteriaceae family wherein the L-amino acid productivity of said bacterium is enhanced by the use of the acetolactate synthase (AHAS I) which is resistant to feedback inhibition by L-valine. This acetolactate synthase contains a mutant small subunit encoded by the mutant ilvN gene.

Abstract: The invention relates to a bacterium comprising an inactive mlc gene which produces an L-amino acid, such as L-threonine,

Abstract: A process for producing an L-amino acid, such as L-isoleucine, L-histidine, L-threonine and L-tryptophan, using bacterium belonging to the genus Escherichia is provided which comprises cultivating the L-amino acid-producing bacterium in a culture medium and collecting the L-amino acid from the culture medium, wherein the culture medium contains a mixture of glucose and pentose sugars, such as arabinose and xylose.