Strains of Escherichia coli which produce isoleucine or valine and a method for their production

摘要

A method for constructing microorganism strains which produce amino acids comprising: combining in one bacterial genome (a) a mutation affecting the aminoacyl-tRNA synthetase corresponding to the selected amino acid, conferring cells auxotrophy which cannot be fully suppressed by addition of usual concentration this amino acid into the culture medium and (b) a mutation which destroys the negative regulation of selected amino acid biosynthesis to yield a strain capable of increased production of the selected amino acid. Strains producing isoleucine and valine. Methods to produce isoleucine and valine by culturing those strains.