Characterization of Two Purified Amylase Produced from <i>Aspergillus niger</i> ICP2 and its Immobilization Using Activated Carbon

Abstract

Amylase is essential in the industrial sector, but there are some challenges with its low reusability efficiency. The catalytic activity of the amylase can be affected by using an activated carbon matrix as an immobilization technique. In this study, we characterized the purified amylase of Aspergillus niger ICP2 and immobilized it to activated carbon. Amylase production from A. niger ICP2 was performed throughout a 7-day incubation. After partial purification, two amylase fractions were generated, including 90% saturation ammonium sulfate precipitation, a 10-kDa hollow fiber dialysis column, and anion exchange chromatography. Thin-layer chromatography analysis showed the presence of glucose in fractions I and II, indicating glucoamylase activity. Both fractions had optimum pH and temperatures at 4.5 and 70°C, respectively. Fraction I was stable at acidic pH (3.5-5), while the stability of fraction II was in the range of acid to base (4-7.5) after incubation for 1 hour at 37°C. Both fractions displayed the same pattern of temperature stability (30-50°C) when incubated for 1 hour at optimum buffer. Activated carbon was used to immobilize amylase fraction II, which demonstrated the ability to hydrolysis the starch up to five times with a reduction in the activity of 50.4%. These results showed promising hydrolysis reusability by amylase immobilized using activated carbon.