摘要:
A method of producing coryneform bacteria having an improved amino acid or nucleic acid-productivity comprises the steps of introducing a mutation in a promoter sequence of amino acid- or nucleic acid-biosynthesizing genes on a chromosome of a coryneform bacterium so that it is close to a consensus sequence or introducing a change in the promoter sequence of amino acid- or nucleic acid-biosynthesizing genes on the chromosome of a coryneform bacterium by gene recombination so that it is close to a consensus sequence, obtaining mutants of the coryneform amino acid- or nucleic acid-producing microorganism, culturing the mutants and select a mutant capable of producing the intended amino acid or nucleic acid in a large amount. This method allows one of skill in the art to construct a mutant capable of enriching or controlling the expression of an intended gene without using a plasmid and to promote production of amino acids in a high yield, by the recombination or mutation.
摘要:
A method of producing coryneform bacteria having an improved amino acid- or nucleic acid-productivity comprises the steps of introducing a mutation in a promoter sequence of amino acid- or nucleic acid-biosynthesizing genes on a chromosome of a coryneform bacterium to make it close to a consensus sequence or introducing a change in a promoter sequence of amino acid- or nucleic acid-biosynthesizing genes on a chromosome of a coryneform bacterium by gene recombination to make it close to a consensus sequence, to obtain mutants of the coryneform amino acid d- or nucleic acid-producing microorganism, culturing the mutants and select a mutant capable of producing the intended amino acid or nucleic acid in a large amount. This method can construct a mutant capable of suitably enriching or controling the expression of an intended gene without using a plasmid and also capable of producing amino acids in a high yield, by the recombination or mutation.
摘要:
A method of producing coryneform bacteria having improved amino acid or nucleic acid productivity comprising the steps of introducing a mutation in a promoter sequence of amino acid- or nucleic acid-biosynthesizing genes on a chromosome of a coryneform bacterium to make it close to a consensus sequence, or introducing a change in a promoter sequence of amino acid- or nucleic acid-biosynthesizing genes on a chromosome of a coryneform bacterium by gene recombination to make it close to a consensus sequence, to obtain mutants of the coryneform amino acid- or nucleic acid-producing microorganism, culturing the mutants and selecting a mutant capable of producing the intended amino acid or nucleic acid in a large amount. This method allows the construction of a mutant capable of enriching or controlling the expression of an intended gene without using a plasmid and to promote production of amino acids in a high yield by recombination or mutation.
摘要:
A coryneform bacterium in which a DNA fragment is incorporated into its chromosome is prepared by (a) obtaining a recombinant plasmid through ligation of a DNA fragment having a sequence homologous to a gene present on a chromosome of a coryneform bacterium to a plasmid that has a wild-type replication control region segment of a particular nucleotide sequence including a mutation and is autonomously replicable in a coryneform bacterium cell at a culture temperature lower than 31° C. but not autonomously replicable in the cell at a temperature of 31° C. or higher, (b) introducing the recombinant plasmid into the coryneform bacterium cell, (c) culturing the bacterium at a temperature of 31° C. or higher, (d) causing homologous recombination between the DNA fragment and the gene present on the chromosome of the coryneform bacterium and having a sequence homologous to the DNA fragment, and (e) selecting a coryneform bacterium in which the DNA fragment is incorporated into its chromosome. According to the present invention, there is provided a method for efficiently modifying genetic traits of a host in a short period of time by obtaining a temperature sensitive plasmid from a plasmid not exhibiting homology with already reported temperature sensitive plasmids or not exhibiting incompatibility therewith.
摘要:
A plurality of primer sets are designed based on a region where conservation at the amino acid level is observed among various microorganisms for known gene sequences corresponding to a gene coding for an enzyme of the L-amino acid biosynthetic pathway derived from Corynebacterium thermoaminogenes, preferably an enzyme that functions at a higher temperature compared with that of Corynebacterium glutamicum. PCR is performed by using the primers and chromosomal DNA of Corynebacterium thermoaminogenes as a template. The primers with which an amplification fragment has been obtained are used as primers for screening to select a clone containing a target DNA fragment from a plasmid library of chromosomal DNA of Corynebacterium thermoaminogenes.
摘要:
A plurality of primer sets are designed based on a region where conservation at the amino acid level is observed among various microorganisms for known gene sequences corresponding to a gene coding for an enzyme of the L-amino acid biosynthetic pathway derived from Corynebacterium thermoaminogenes, preferably an enzyme that functions at a higher temperature compared with that of Corynebacterium glutamicum. PCR is performed by using the primers and chromosomal DNA of Corynebacterium thermoaminogenes as a template. The primers with which an amplification fragment has been obtained are used as primers for screening to select a clone containing a target DNA fragment from a plasmid library of chromosomal DNA of Corynebacterium thermoaminogenes.
摘要:
A plurality of primer sets are designed based on a region where conservation at the amino acid level is observed among various microorganisms for known gene sequences corresponding to a gene coding for an enzyme of the L-amino acid biosynthetic pathway derived from Corynebacterium thermoaminogenes, preferably an enzyme that functions at a higher temperature compared with that of Corynebacterium glutamicum. PCR is performed by using the primers and chromosomal DNA of Corynebacterium thermoaminogenes as a template. The primers with which an amplification fragment has been obtained are used as primers for screening to select a clone containing a target DNA fragment from a plasmid library of chromosomal DNA of Corynebacterium thermoaminogenes.
摘要:
A plurality of primer sets are designed based on a region where conservation at the amino acid level is observed among various microorganisms for known gene sequences corresponding to a gene coding for an enzyme of the L-amino acid biosynthetic pathway derived from Corynebacterium thermoaminogenes, preferably an enzyme that functions at a higher temperature compared with that of Corynebacterium glutamicum. PCR is performed by using the primers and chromosomal DNA of Corynebacterium thermoaminogenes as a template. The primers with which an amplification fragment has been obtained are used as primers for screening to select a clone containing a target DNA fragment from a plasmid library of chromosomal DNA of Corynebacterium thermoaminogenes.
摘要:
A plurality of primer sets are designed based on a region where conservation at the amino acid level is observed among various microorganisms for known gene sequences corresponding to a gene coding for an enzyme of the L-amino acid biosynthetic pathway derived from Corynebacterium thermoaminogenes, preferably an enzyme that functions at a higher temperature compared with that of Corynebacterium glutamicum. PCR is performed by using the primers and chromosomal DNA of Corynebacterium thermoaminogenes as a template. The primers with which an amplification fragment has been obtained are used as primers for screening to select a clone containing a target DNA fragment from a plasmid library of chromosomal DNA of Corynebacterium thermoaminogenes.
摘要:
L-Glutamic acid is produced by culturing in a liquid culture medium a microorganism belonging to the genus Pantoea or Serratia and having an ability to produce L-glutamic acid, which increases in an activity of enzyme catalyzing a reaction for L-glutamic acid biosynthesis or which decreases in or is deficient in an activity of an enzyme catalyzing a reaction branching from a pathway for L-glutamic acid biosynthesis and producing a compound other than L-glutamic acid, and collecting produced L-glutamic acid from the culture medium.