| 摘要 |
PURPOSE:To industrially and advantageously obtain the titled compound useful as a feed additive, etc., by enzymically reacting alpha-ketobutyric acids with pyruvic acids in the presence of microbial cells of the genus Brevibacterium requiring biotin in an aqueous solution containing ethanol. CONSTITUTION:alpha-Ketobutyric acid or a salt thereof is reacted with pyruvic acid or a salt thereof in the presence of microbial cells [e.g. Brevibacterium flavum MJ-233 (FERM-P No.3068)] belonging to the genus Brevibacterium requiring biotin in an aqueous solution containing at least ethanol to produce L- isoleucine in the solution. The resultant reaction solution is then centrifuged to separate the microbial cells and collect a supernatant, which is subsequently passed through a strong acidic cation exchange column to elute an adsorbed substance. Thereby the aimed L-isoleucine is obtained. |
