Production, Purification, and Characterization of Thermostable α-Amylase Produced by Bacillus licheniformis Isolate AI20

Table 7

Effect of different divalent metal ions on the purified α-amylase enzyme activity produced by Bacillus licheniformis AI20.

Treatment	Residual α-amylase activity (%)
	at 0.1 mM	at 1.0 mM	at 10.0 mM
Control	100	100	100
Ca^2+	107.83	100.41	100
Mg^2+	95.44	92.52	104.96
Co^2+	102.61	91.28	92.09
Mn^2+	100.87	100.31	96.49
Cu^2+	99.67	93.55	24.73
Zn^2+	94.02	92.80	54.72
Hg^2+	42.07	0.00	0.00