L-Valine → L-Lysine

Participants

Reaction Steps

Each strain was cultured in NB medium at 30° C. for 16 hours. For the culture of the transformants, spectinomycin was added to NB medium at a concentration of 100 μg/ml. Then, 0.5 ml of the seed culture was inoculated into 5 ml of a production medium (pH 7.2) comprising 100 g/l lactose, 30 g/l (NH4)2SO4, 0.5 g/l KH2PO4, 0.5 g/l K2HPO4, 1 g/l MgSO4 ·7H2O, 10 mg/l FeSO4 ·7H2O, 10 mg/l MnSO4 ·7H2O, 100 μg/l biotin and 30 g/l CaCO3 in a test tube. Homoserine (100 μg/ml) was further added to the production medium for RH6 strain and its transformant, and 100 μg/ml each of threonine, isoleucine and valine were added to the production medium for ATCC 21086 strain and its transformant. Shaking culture was carried out at 30° C. for 72 hours. After the culturing was finished, the amount of L-lysine formed was colorimetrically determined by the acidic copper ninhydrin method [Chinard, J. Biol. Chem., 199, 91 (1952)]. The results are shown in Table 7.

Provenance & Evidence