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-2016201100-A1
Application number	US-201615082274-A
Country	US
Kind code	A1
Filing date	Mar 28, 2016
Priority date	Oct 2, 2013
Publication date	Jul 14, 2016
Grant date	—

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

1 . A method for producing an L-amino acid comprising:
(i) cultivating an L-amino acid-producing bacterium of the family Enterobacteriaceae 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.

2 . The method according to claim 1 , wherein said bacterium belongs to the genus Escherichia.

3 . The method according to claim 2 , wherein said bacterium is Escherichia coli.

4 . The method according to claim 1 , wherein said bacterium belongs to the genus Pantoea.

5 . The method according to claim 4 , wherein said bacterium is Pantoea ananatis.

6 . 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.

7 . The method according to claim 6 , wherein said phosphate transporter-encoding gene is deleted.

8 . The method according to claim 1 , 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 one or several amino acid residues, and wherein said protein has inorganic phosphate-transporting activity.

9 . The method according to claim 1 , wherein said L-amino acid is selected from the group consisting of an aromatic L-amino acid and a non-aromatic L-amino acid.

10 . The method according to claim 9 , wherein said aromatic L-amino acid is selected from the group consisting of L-phenylalanine, L-tryptophan, and L-tyrosine.

11 . The method according to claim 9 , wherein said non-aromatic L-amino acid is selected from the group consisting of L-alanine, L-arginine, L-asparagine, L-aspartic acid, L-citrulline, L-cysteine, L-glutamic acid, L-glutamine, glycine, L-histidine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-ornithine, L-proline, L-serine, L-threonine, and L-valine.

12 . The method according to claim 1 , wherein said L-amino acid is L-arginine and L-histidine.

Assignees

• Ajinomoto Kk

Inventors

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

Classifications

• C07K14/24 Primary

  from Enterobacteriaceae (F), e.g. Citrobacter, Serratia, Proteus, Providencia, Morganella, Yersinia · CPC title

• C12P13/10

  Citrulline; Arginine; Ornithine · CPC title

• C12P13/06

  Alanine; Leucine; Isoleucine; Serine; Homoserine · CPC title

• C12P13/14

  Glutamic acid; Glutamine · CPC title

• C12P13/222

  Phenylalanine · CPC title