Method for producing an amino acid using a bacterium overexpressing an rhtC gene

摘要

The present invention describes a bacterium which has an ability to produce an amino acid and in which the rhtC gene encoding a protein having an enhanced activity of imparting L-threonine resistance to a bacterium expressing the protein. Preferably, the bacterium further includes an rhtB gene encoding for a protein having an enhanced activity of imparting to a bacterium L-homoserine resistance expressing the protein. The present invention also describes a method of cultivating the bacterium in a culture medium to produce and accumulate amino acids in the medium, and the amino acid is recovered from the medium.

主权项

1. A method of producing an L-amino acid selected from the group consisting of L-homoserine and L-threonine comprising the steps of:
A) cultivating in a culture medium an Escherichia coli which has been modified to increase expression of a DNA, wherein expression of said DNA is increased by increasing the copy number of said DNA or replacing a promoter sequence of said DNA with a promoter sequence which functions in said Escherichia coli, wherein said DNA comprises the nucleotide sequence of nucleotides 187 to 804 of SEQ ID NO: 3; B) removing solids including cells from the medium; and C) purifying said L-amino acid from the medium obtained in step B).