| 摘要 |
PURPOSE:To efficiently obtain L-valine useful as a medicine, food, feed additive, etc., by enzymically reacting specific microbial cells in an aqueous solution containing glucose. CONSTITUTION:Brevibacterium.flavum MJ-233, requiring biotin and belonging to the genus Brevibacterium is aerobically cultivated in a culture medium containing glucose, urea, etc., at 20-40 deg.C and pH5-10 for 0.5-3 days to separate and wash microbial cells and afford microbial cells (A) for enzymic reaction. Glucose in an amount of 0.5-20wt.% is then added to an aqueous solution (B) of a synthetic complete culture medium containing 2g/l (NH4)2SO4, 0.5g/l KH2PO4, 0.5g/l K2HPO4, 0.5g/l MgSO4.7H2O, 20ppm FeSO4, 20ppm MnSO4, etc., at about pH7.6 and 1-50wt.% microbial cells (A) is subsequently added. Air, etc., is continuously or intermittently fed so as to provide 0.05-8ppm dissolved oxygen concentration at 20-50 deg.C and reacted for 10-72hr. The aimed L-valine formed in the reaction solution is then separated and recovered. |
