An L-amino acid-producing strain of Escherichia coli is bred by modifying
an Escherichia coli K12 strain or a derivative thereof so as to become
resistant to L-valine and have an ability to produce one or more L-amino
acids selected from the group consisting of L-tryptophan,
L-phenylalanine, L-lysine, L-tyrosine, L-glutamic acid, L-histidine,
L-cysteine, and L-proline.