PURPOSE: To produce L-tryptophan which is an essential amino acid, at a low cost, by culturing a tryptophanase-deficient microbial strain belonging to Providencia genus in a nutrient medium.
CONSTITUTION: Providencia rettgeri ATCC 9910 is irradiated with ultraviolet radiation or treated with a mutagenic agent and cultured in a plate medium containing L-tryptophan as main nitrogen source or carbon source at 30°C for 3W5 days. A small colony having low growth rate is separated by fishing to obtain a tryptophanasedeficient strain, Providencia rettgeri TN-33 (FERM P-8777). L-tryptophan can be produced by culturing the strain in a medium containing 2W15% carbon source (sugar, organic acid, alcohol, etc.), 0.5W4.0% nitrogen source (organic or inorganic ammonium salt, urea, etc.) and other inorganic salt, etc., at 5W9 pH and 24W37°C for 48W120hr under aerobic condition.
| JPS61181392 | PRODUCTION OF L-DOPA |
| JPS6174589 | PRODUCTION OF L-TRIPTOPHANE |
| JP3225597 | PRODUCTION OF L-PHENYLALANINE BY FERMENTATION METHOD |
MORI CHIZUKO
YOMOTO KYOSUKE
