| 摘要 |
PURPOSE: To efficiently produce fumaric acid useful for foods, medicines, industrial raw materials, etc., by suppressing the dissolved oxygen concentration to a specific value or below and carrying out the isomerizing reaction of a microorganism (a prepared substance) having maleic isomerase activities with maleic acid in an aqueous solution. CONSTITUTION: A microorganism having maleic isomerase activities (e.g. Alcaligenes faecalis IFO12669 strain) or a prepared substance thereof is mixed with maleic acid in an aqueous solution and the resultant reactional solution is then sealed with one or more gases such as N2 , Ar or He to maintain the dissolved oxygen in the reactional solution at <=4ppm. Enzymic isomerizing reaction is then carried out to isomerize the maleic acid into fumaric acid. Thereby, the objective fumaric acid useful as a raw material for producing L-aspartic acid, L-malic acid, L-alanine, etc., useful as foods, medicines or industrial raw materials is efficiently obtained in high yield. |
