反应详情

After culturing at 30° C. for 2 weeks, about 10,000 colonies resistant to chloramphenicol appeared, which were replicated in threonine-free medium (Thr deficient medium) which contained 2% of glucose, 1% of ammonium sulfate, 0.25% of urea, 0.1% of dihydrogen potassium phosphate, 0.04% of magnesium sulfate heptahydrate, 1 mg/dl of FeSO4.7H2O, 1 mg/dl of MnSO4.4H2O, 200 μg/dl of thiamine hydrochloride and 50 μg/dl of biotin, pH 7.0, 1.8% of agar, and 3 strains which were resistant to chloramphenicol and tryptophan independent were obtained.