Isolation and Partial Purification of Acidic Amylases from Manihot esculenta , Crantz (Cassava) Peel

摘要

Manihot esculenta, Crantz (Cassava) peel was taken for the isolation of acidic amylases. The enzyme activity of 20% and 40% precipitate was found to be 0.02 and 0.18μmole/min, whereas, 50% precipitate did not show any enzyme activity. The fractionation of 40% precipitate on Sephadex G-75 column yielded two peaks with enzyme activity 0.02 and 0.08μmole/min respectively. The second peak indicated a rich source of amylase. A gradual increase in the enzyme activity was observed at 350C to 500C, along with drastic decrease at 500C onwards. A maximum activity was observed from 500C at pH 6.8 to 7.0. The activity of purified enzyme was 0.14μmole/min.Besides, substrate concentration between 1 to 3% which led to substantial increase in enzyme activity. Further, the enzyme activity of Cassava amylase against commercial starch was tested and found that, the enzyme activity increased with increase in time and remains constant after 80th min, whereas, on its own starch there was no activity till 30th min and after this time point, the activity gradually increases and it remains constant after 90 minutes. Thus, indicating Cassava acidic amylases act very rapidly on commercial starch than on its own starch.