| 摘要 |
PURPOSE:To prepare L-tryptophan in high yield by fermentation, by using a strain of a specific variant belonging to the genus Bacillus. CONSTITUTION:A bacterium belonging to the genus Bacillus, as a parent strain having tryprophan analog resistance, capable of producing tryptophan, is subjected to operation of variation and induction (ultraviolet-light irradiation, treatment with a chemical reagent such as N-methyl-N'-nitro-N-nitrosoguanidine, etc.) to give a strain of variant[e.g., Bacillus subtilis AJ 11741 FERM-P 6253(5-fluorotryptophan resistance, 6-diazo-5-oxo-L-norleucine resistance)], and it is used. Namely, the strain of variant capable of producing L-tryptophan is cultivated aerobically in a liquid medium, the mold is removed from the culture solution, and the culture solution is concentrated (or by ion exchange chromatography), to give L-tryptophan. |
