RU96115144A - FERMENTATION METHOD FOR PRODUCING L-LYSINE - Google Patents

Claims (14)

1. DNA encoding a dihydrodipicolinate synthase obtained from a bacterium belonging to the genus Escherichia, containing a mutation that desensitizes feedback inhibition by L-lysine.  2. DNA according to claim 3, characterized in that the mutation that desensitizes the feedback inhibition due to L-lysine is selected from the group consisting of mutations replacing the 81st alanine residue with a valine residue, mutations replacing the 118th histidine residue tyrosine residue, mutations of the replacement of the 81st alanine residue with a valine residue and the replacement of the 118th histidine residue with a tyrosine residue, counting from the N-terminus of the amino acid sequence of dihydrodipicolinate synthase shown in sequence ID N 3 in the description of the last quently.  3. A bacterium belonging to the genus Escherichia, transformed by introducing into its cells a DNA encoding a dihydrodipicolinate synthase, obtained from a bacterium belonging to the genus Escherichia, and containing a mutation that desensitizes feedback inhibition by L-lysine.  4. A bacterium belonging to the genus Escherichia according to claim 3, characterized in that the mutation that desensitizes feedback inhibition due to L-lysine is selected from the group consisting of a mutation of the 81st alanine residue with a valine residue, a 118 mutation of the histidine residue with a tyrosine residue, and mutations in the replacement of the 81st alanine residue with a valine residue and the replacement of the 118th histidine residue with a tyrosine residue, counting from the N-terminus of the amino acid sequence and dihydrodipicolinate synthase determined in the sequence The characteristics of ID N 4 in the description of sequences.  5. A bacterium belonging to the genus Escherichia according to claim 3, characterized in that it also contains aspartokinase, in which feedback inhibition by L-lysine is desensitized.  6. The bacterium belonging to the genus Escherichia according to claim 5, characterized in that it contains aspartokinase, in which feedback inhibition by L-lysine is desensitized, which is achieved by introducing into its cells a DNA encoding aspartokinase III, obtained from bacteria belonging to the genus Escherichia containing a mutation that desensitizes feedback inhibition by L-lysine.  7. The bacterium belonging to the genus Escherichia according to claim 6, characterized in that the mutation for desensitizing inhibition by the feedback type of aspartokinase III due to L-lysine is selected from the group consisting of a mutation replacing the 323rd glycine residue with an aspartic acid residue, a mutation replacing the 323rd glycine residue with an aspartic acid residue and replacing the 408th glycine residue with an aspartic acid residue, mutating the replacement of the 34th arginine residue with a cysteine residue and replacing the 323rd glycine residue with an aspartic acid residue you, mutations replacing the 325th leucine residue with a phenylalanine residue, mutations replacing the 318th methionine residue with an isoleucine residue, mutations replacing the 318th methionine residue with an isoleucine residue and replacing the 349th valine residue with a methionine residue, mutations replacing the 345th leucine serine mutations replacing the 347th residue with a methionine residue, mutations replacing the 352nd threonine residue with an isoleucine residue, mutations replacing the 352nd threonine residue with an isoleucine residue and replacing the 369th serine wasp a tatka with a phenylalanine residue, mutations in the replacement of the 164th residue of glutamic acid with a lysine residue and mutations in the replacement of the 417th methionine residue with an isoleucine residue and the replacement of the 419th cysteine residue with a tyrosine residue, counting from the N-terminus of the amino acid sequence of aspartokinase III defined in sequence N 9 in the description of the sequences.  8. The bacterium belonging to the genus Escherichia, according to claim 5, characterized in that the dihydrodipicolinate reductase gene is amplified.  9. A bacterium belonging to the genus Escherichia according to claim 8, characterized in that it is transformed with a recombinant DNA constructed by ligating the dihydrodipicolinate reductase gene with a vector autonomously replicating in bacterial cells belonging to the genus Escherichia.  10. The bacterium belonging to the genus Escherichia according to claim 8, characterized in that the amplified diaminopimelate dehydrogenase gene obtained from the coryneform bacterium is introduced into it.  11. The bacterium belonging to the genus Escherichia according to claim 10, characterized in that it is transformed with a recombinant DNA constructed by ligation of a gene of diaminopimelate dehydrogenase derived from coryneform bacteria with a vector autonomously replicating in the cells of a bacterium belonging to the genus Escherichia.  12. The bacterium belonging to the genus Escherichia according to claim 8, characterized in that the genes of succinyl diaminopimelattransaminase and succinyl diaminopimelate deacylase are strengthened therein.  13. A bacterium belonging to the genus Escherichia according to claim 12, characterized in that it is transformed with one recombinant DNA or two recombinant DNAs constructed by ligation of the succinyl diaminopimelate transaminase gene and the succinyl diaminopimelate deacylase gene with identical vectors or with different vectors, belonging to the genus Escherichia.  14. A method of producing L-lysine, characterized in that it includes the steps of culturing a bacterium belonging to the genus Escherichia according to any one of claims 3 to 13 in an appropriate medium, producing and accumulating L-lysine in its culture, and isolating L-lysine from this culture .