Abstract: There is disclosed a method for producing L-amino acid, for example L-threonine, L-lysine, L-histidine, L-phenylalanine, L-arginine or L-glutamic acid, using a bacterium of the Enterobacteriaceae family, wherein the bacterium has been modified to enhance an activity of D-xylose permease.

Abstract: L-arginine, citrulline and pyrimidine derivatives including orotic acid, uridine, uridine 5?-monophosphate (UMP), cytidine and cytidine. 5?-monophosphate (CMP) are produced using a bacterium belonging to the genus Escherichia harboring a mutant carbamoylphosphate synthetase in which the amino acid sequence corresponding to positions from 947 to 951 in a wild type carbamoylphosphate synthetase is replaced with any one of amino acid sequences of SEQ ID NOS: 1 to 9, and feedback inhibition by uridine 5?-monophosphate in the bacterium is desensitized.

Abstract: Amino acids, such as L-glutamine, L-arginine, L-tryptophan, L-histidine and L-glutamate are produced using a bacterium belonging to the genus Escherichia harboring a mutant glutamine synthetase in which the tyrosine amino acid residue corresponding to position 397 in a wild type glutamine synthetase is replaced with any of amino acid residues, preferably with phenylalanine.

Abstract: There is provided a method for producing L-threonine, L-valine, L-proline, L-leucine, L-methionine and L-arginine using bacterium belonging to the genus Escherichia wherein L-amino acid productivity of the bacterium is enhanced by enhancing an activity of proteins coded by b2682 and b2683 genes, or protein coded by b1242 or b3434 gene.

Abstract: A method for producing an L-amino acid, such as L-histidine, L-threonine, L-lysine, L-glutamic acid, and L-tryptophan, using bacterium belonging to the genus Escherichia which has increased expression of genes, such as those of the xylABFGHR locus, which encode the xylose utilization enzymes, is disclosed. The method includes cultivating the L-amino acid producing bacterium in a culture medium containing xylose, and collecting the L-amino acid from the culture medium.

Abstract: A method is provided for producing L-cysteine using a bacterium belonging to the genus Escherichia, wherein the L-amino acid productivity of said bacterium is enhanced by increasing expression of the cysPTWAM cluster genes.

Abstract: O-acetylserine, L-cysteine and sulphurous compounds derived therefrom may be produced using a bacterium belonging to the genus Escherichia which harbors a mutant feedback-resistant serine acetyltransferases in which the amino acid sequence corresponding to positions from 89 to 96 in a wild-type serine acetyltransferase is replaced with any one of the amino acid sequences shown in SEQ ID NOS: 4 to 9, and feedback inhibition by L-cysteine in the bacterium is desensitized.

Abstract: Arginine can be efficiently produced by cultivating Escherichia coli which has an ability to produce arginine and an ability to utilize acetate in a culture medium to produce and accumulate arginine in the medium, and collecting arginine from the medium.

Abstract: L-arginine is produced using a bacterium belonging to the genus Escherichia harboring a mutant N-acetylglutamate synthase in which the amino acid sequence corresponding to positions from 15 to 19 in a wild type N-acetylglutamate synthase is replaced with any one of amino acid sequences of SEQ ID NOS: 1 to 4, and feedback inhibition by L-arginine is desensitized.