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.
摘要:
A method for producing an L-amino acid, such as L-phenylalanine and L-threonine, is provided using an Escherichia bacterium, wherein the L-amino acid productivity of said bacterium is enhanced by enhancing the activity of the protein encoded by the yedA gene. A further method is provided for producing a lower alkyl ester of α-L-aspartyl-L-phenylalanine by producing L-phenylalanine by cultivating an Escherichia coli bacterium in a medium, wherein said bacterium has the ability to produce L-phenylalanine, and synthesizing the lower alkyl ester of α-L-aspartyl-L-phenylalanine from aspartic acid, or a derivative thereof, and the produced L-phenylalanine.
摘要:
A method for producing an L-amino acid, such as L-phenylalanine and L-threonine, is provided using an Escherichia bacterium, wherein the L-amino acid productivity of said bacterium is enhanced by enhancing the activity of the protein encoded by the yedA gene. A further method is provided for producing a lower alkyl ester of α-L-aspartyl-L-phenylalanine by producing L-phenylalanine by cultivating an Escherichia coli bacterium in a medium, wherein said bacterium has the ability to produce L-phenylalanine, and synthesizing the lower alkyl ester of α-L-aspartyl-L-phenylalanine from aspartic acid, or a derivative thereof, and the produced L-phenylalanine.
摘要:
A method for producing an L-amino acid, such as L-phenylalanine or L-threonine, is provided using a bacterium belonging to the genus Escherichia, wherein the L-amino acid productivity of said bacterium is enhanced by enhancing an activity of the protein encoded by the yedA gene.
摘要:
A method for producing lower alkyl ester of α-L-aspartyl-L-phenylalanine by cultivating a recombinant Escherichia coli bacterium that has the ability to produce and accumulate an aromatic L-amino acid according in a culture medium to produce and accumulate L-phenylalanine in the medium and synthesizing lower alkyl ester of α-L-aspartyl-L-phenylalanine from the aspartic acid or its derivative and the obtained L-phenylalanine.
摘要:
Amino acids such as threonine, homoserine, isoleucine, lysine, valine and tryptophan are produced using a bacterium belonging to the genus Escherichia which has been constructed from a sucrose non-assimilative strain belonging to the genus Escherichia and which harbors sucrose non-PTS or PTS genes and has an ability to produce the amino acid.
摘要:
An amino acid such as threonine, homoserine, isoleucine, lysine, valine and tryptophan is produced using a bacterium belonging to the genus Escherichia which has been constructed from sucorse non-assimilative strain belonging to the genus Escherichia and which harbors sucrose non-PTS (phosphoenol pyruvate-dependent sucrose-6-phosphotransferase system) genes and has an ability to produce the amino acid.
摘要:
A method for producing lower alkyl ester of α-L-aspartyl-L-phenylalanine by cultivating a recombinant Escherichia coli bacterium that has the ability to produce and accumulate an aromatic L-amino acid according in a culture medium to produce and accumulate L-phenylalanine in the medium and synthesizing lower alkyl ester of α-L-aspartyl-L-phenylalanine from the aspartic acid or its derivative and the obtained L-phenylalanine.
摘要:
The present invention relates to a method for producing L-amino acid, such as L-phenylalanine and L-tryptophan, is provided using bacterium belonging to the genus Escherichia wherein the L-amino acid productivity of said bacterium is enhanced by enhancing an activity of protein encoded by the yddG gene from Escherichia coli, wherein said protein has an activity to make said bacterium resistant to L-phenylalanine, a phenylalanine analogue, or a tryptophan analogue. The present invention further relates to a method for producing lower alkyl ester of α-L-aspartyl-L-phenylalanine.
摘要:
The present invention provides an isolated DNA molecule encoding a small subunit of acetohydroxy acid synthase isozyme III originating from Escherichia coli and mutants of Escherichia coli acetohydroxy acid synthase isozyme III, which are free from inhibition by L-valine an can catalyze the conversion of: (a) pyruvate to &agr;-acetolactate and (b) &agr;-ketobutyrate and pyruvate to &agr;-aceto-a-hydroxybutyrate. The present invention also provides methods for producing L-valine by fermentation of a bacterium harboring the novel DNA molecule and/or expressing the mutant acetohydroxy acid synthase isozyme III.