| 摘要 |
PROBLEM TO BE SOLVED: To obtain a novel bacterium that is capable of producing L-leucine, comprises a bacterium in Escherichia coil that is resistant to L-leucine and is useful for inexpensive and efficient production of L-leucine useful as a nutrient additive, as a chemical new material and for medical eare and for pharmaceutical industry. SOLUTION: This microorganism is a bacterium in Escherichia coil that is capable of producing L-leucine and resistant to L-leucine (for example, Escherichia coli K-12 No.57) and is useful for inexpensive and efficient production of L-leucine that is useful as a nutrient additive for foods and feeds, for a reagent in medical care, a medicine pharmaceutical a chemical industries, or as a growth factor as an essential amino acid for microorganisms to be used for producing other amino acids, for example, lysine. This novel bacterium is obtained by culturing Escherichia coli K-12 strain in a culture medium containing L-leucine, selecting growing strains and subjecting the growing strains to an artificial mutation treatment to select L-leucine-producing strains. |
