The genes for a threonine deaminase that is resistant to feedback inhibition by l-isoleucine and for an active acetohydroxyacid synthase II were introduced by a plasmid into a l- threonine-producing recombinant strain of Escherichia coli K-12. Analysis of culture broth of the strain using 13C nuclear magnetic resonance suggested that α, β-dihydroxy-β- methylvalerate (DHMV) and α-keto-β-methylvalerate (KMV), the third and the fourth ...
