| 摘要 |
PURPOSE:To obtain the titled substance in high conversion ratio and advantageously, by maintaining partial pressure of dissolved oxygen in an enzyme reaction solution at fixed pressure in converting a 5-substituted hydantoin into the titled substance by the use of a fungus belonging to the genus Hansenula. CONSTITUTION:A 5-substituted hydantoin shown by formula I (R is alkyl group, phenyl group, etc.) is treated with a culture solution of a fungus such as Hansenula ciferrii, Hansenula henricii, etc., belonging to the genus Hansenula, a cell or a treated material thereof. In the operation, partial pressure of dissolved oxygen in the enzyme reaction solution is maintained of <=0.1atm. by replacing air with nitrogen gas, etc., fully charging the whole container with the reaction solution, adding an antioxidant, etc. A D-alpha-amino acid shown by formula II (R is the same) is separated and collected by using ion exchange resin, etc. |
