α-Glucuronidase from
Aspergillus niger specific for
O-α-
D-glucosyluronic acid α-
D-glucosiduronic acid (trehalose dicarboxylate, TreDC) was hydrolyzed TreDC to produce
D-glucuronic acid. For the application of the α-glucuronidase to
D-glucuronic acid production, the enzyme was immobilized on a baked diatomite. The immobilized enzyme treated with glutaraldehyde retained about 60% of the initial activity after repeated uses of 20 cycles. Although the immobilized enzyme completely hydrolyzed 100 m
M TreDC, the reaction was significantly inhibited by
D-glucuronic acid over 200 m
M TreDC. To hydrolyze TreDC completely, the reaction mixture was diluted with buffer to keep the
D-glucuronic acid concentration below 300-400 m
M. The immobilized enzyme in the diluted reaction mixture hydrolyzed 500 m
M TreDC (initial concentration) almost completely to produce
D-glucuronic acid. The immobilized enzyme packed in a column continuously produced
D-glucuronic acid and the activity of the enzyme remained about 80% of the initial activity after 20 days of operation.
View full abstract