Fifty strains of mold which isolated from the various sources were screened for the production of Naringinase which hydrolyse naringin, the 7-rhamnoside- glucoside of 4´.5.7. - trihydroxyflavanonin, the main bitter principle of citrus fruits and grape fruits.
Of the 4 strains yielded naringinase with significant activity, S-1 strain was selected on the criterion of industrial application, and some properties of crude naringinase of this S-1 was investigated.
The results obtained were as follows.
1. Naringenase obtained from S-1 strain has optimum pH range from 3.0 to 5.0 for its activity.
2. Production of naringinase was increased on the addition of naringin to the medium.
3. Hydrolysis of naringin with approporiate concentration of naringinase was carried out linerly up to 80% on the 0.1% substrate solution.
4. The optimum temperature for its activity was 50℃, and this enzyme was inactivated 80% of its total activity at 70℃ for 10 minutes, 40% at 60℃ for 30 minutes.
But signifiant decrease of activity were not occourred by heat treatment at 50℃ for 2 hours.
5. Crude enzyme of the naringinase obtained from S-1 strain was competitively inhibited by addition of glucose on the substrate, and inhibitor constant of the glucose on the this enzyme was 1.5 Mol, and inhibition rate were linearly increased according to the increase of sucrose concentration and 56% of its total activity was inhibited at 1 Mol sucrose solution.
|