| abstract |
Production of 2-hydroxy-4-methylthiobutyric acid (I) and/or its ammonium salt (Ia) from 2-hydroxy-4-methylthiobutyronitrile (II) comprises contacting (II) with an immobilised material having nitrilase (III) activity to generate (Ia), optionally converting this to free acid, and concentrating the product. Also new are: (1) an aqueous solution containing (I) and (Ia) at weight ratio (I)/[(I)+(Ia)] of 5-99.9, preferably 10-50,%; (2) a device for the process, as above, comprising reaction chambers containing immobilised (III) or host cells expressing (III), optionally an electrodialysis unit and a means of concentrating the final product; and (3) the plasmid pRPA-BCAT3 (CBS 998-96). |