Studies on α-Rhamnosidase A and B Produced by Aspergillus niger

1. A fungal enzyme preparation which was made by Aspergillus niger contains two species of α-rhamnosidase at least. One is α1,2-glucorhamnosidase, and the other is α-1,6-glucorhamnosidase. They were named α-Rhamnosidase A and B by the authors. 2. A purified α-Rhamnosidase A was found to hydrolyze neohespridose in naringin and neohesperidin in the PH range of 3 to 6 at temperature of from 30℃ to 60℃, and the most suitable condition for the reaction was found on the PH=4.2 at 55℃. 3. A purified α-Rhamnosidase B was found to hydyrolyze rutinose in hesperidin and rutin in the PH range of 2 to 5 at temperrature of from 40℃ to 70℃, and themost suitable condition for the reaction was found on the PH=3.5 at 60℃. 4. The PH-stabilirty and the Temperature-stubility of these enzymes were studied, and it was found that α-Rhamnosidase B was more stable than A as shown in Fig.3 and 4.