2.6. Partial characterization of amylase
The crude amylase sample was used for characterization studies. The optimum temperature for amylase activity was determined at selected temperatures ranging from 30 °C to 70 °C. The temperature stability of the enzyme was evaluated by incubating the enzyme at these temperatures for 1 h at pH 8.0 and the relative enzyme activity was determined. The enzyme activity was also tested for pH optima ranging from 5.0 to 10.0 using 0.1 M buffer systems (succinate buffer, pH 5.0; phosphate buffer, pH 6.0–7.0; tris–HCl buffer, pH 8.0 and glycine–NaOH buffer, pH 9.0–10.0). In order to determine the enzyme pH stability, the amylase was incubated in buffer at 37 °C for 1 h after which the remaining enzyme activity was determined. The impact of various metal ions (0.010 M) (Ca2+, Co2+, Cu2+, Mg2+, Mn2+, Hg2+, Fe2+, Na+ and Zn2+) was evaluated.