Method for producing an L-amino acid using a bacterium of the family Enterobacteriaceae having attenuated expression of a phosphate transporter-encoding gene

Patent metadata

Field	Value
Publication number	US-9873898-B2
Application number	US-201615082274-A
Country	US
Kind code	B2
Filing date	Mar 28, 2016
Priority date	Oct 2, 2013
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

The present invention provides a method for producing an L-amino acid by fermentation using a bacterium of the family Enterobacteriaceae. The bacterium can belong to the genus Escherichia , which has been modified to attenuate expression of a phosphate transporter-encoding gene, such as the pitA gene or pitB gene.

First claim

The invention claimed is:

1. A method for producing an L-amino acid selected from the group consisting of L-His, L-Arg, or combinations thereof, said method comprising:
(i) cultivating an L-amino acid-producing Escherichia coli bacterium in a culture medium to produce and accumulate an L-amino acid in the culture medium or cells of the bacterium, or both; and
(ii) collecting the L-amino acid from the culture medium or cells of the bacterium, or both,
wherein said bacterium has been modified to attenuate expression of a phosphate transporter-encoding gene and
wherein said phosphate transporter-encoding gene is selected from the group consisting of:
(A) a DNA comprising the nucleotide sequence of SEQ ID NO: 1;
(B) a DNA comprising the nucleotide sequence of SEQ ID NO: 3;
(C) a DNA comprising a variant nucleotide sequence of SEQ ID NO: 1 or SEQ ID NO: 3 due to the degeneracy of the genetic code;
(D) a DNA having an identity of the nucleotide sequence of not less than 75% with respect to the entire nucleotide sequence of SEQ ID NO: 1 or SEQ ID NO: 3, and wherein said nucleotide sequence encodes a protein having inorganic phosphate-transporting activity;
(E) a DNA encoding a protein comprising the amino acid sequence of SEQ ID NO: 2;
(F) a DNA encoding a protein comprising the amino acid sequence of SEQ ID NO: 4; and
(G) a DNA encoding a protein comprising the amino acid sequence of SEQ ID NO: 2 or SEQ ID NO: 4, but wherein said sequence includes substitutions, deletions, insertions, or additions of 1 to 30 amino acid residues, and wherein said protein has inorganic phosphate-transporting activity.

2. The method according to claim 1 , wherein said expression of the phosphate transporter-encoding gene is attenuated by inactivation of the phosphate transporter-encoding gene.

3. The method according to claim 2 , wherein said phosphate transporter-encoding gene is deleted.

4. The method according to claim 1 , wherein said phosphate transporter-encoding gene is pitA or pitB.

Assignees

• Ajinomoto Kk

Inventors

• Kuvaeva Tatyana Mikhailovna
• Polyakova Evgeniya Aleksandrovna
• Stoynova Natalia Viktorovna

Classifications

• C12P13/227

  Tryptophan · CPC title

• C12P13/24 Primary

  Proline; Hydroxyproline; Histidine · CPC title

• C12P13/10

  Citrulline; Arginine; Ornithine · CPC title

• C12P13/222

  Phenylalanine · CPC title

• C12N1/20

  Bacteria; Culture media therefor · CPC title