Patent ID: 8728774

Claim:
A method for producing L-threonine which comprises cultivating an Escherichia coli in a culture medium to cause accumulation of the L-threonine in the culture medium, and isolating the L-threonine from the culture medium, wherein said Escherichia coli has been modified to enhance an activity of D-xylose permease derived from Enterobacteriaceae family by a method selected from the group consisting of: a) increasing the copy number of a gene encoding D-xylose permease, b) placing the gene encoding D-xylose permease under the control of a potent promoter, and c) combinations thereof, wherein the culture medium contains glucose and does not contain xylose, and L-threonine production from glucose is improved due to enhancing the activity of D-xylose permease in said Escherichia coli.