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

Table 2

Box-Behnken factorial experimental design, representing the response of thermostable α-amylase enzyme activity as influenced by starch, yeast extract, and CaCl₂.

Trial no.	Starch; 𝑋1	Yeast extract; 𝑋2	CaCl2; 𝑋3	Amylase activity measured; (U/mL/min)	Amylase activity predicted; (U/mL/min)
1	−1	−1	0	290.7	287.0
2	1	−1	0	320.8	330.2
3	−1	1	0	183.8	174.4
4	1	1	0	226.0	229.6
5	−1	0	−1	242.9	248.6
6	1	0	−1	311.7	304.3
7	−1	0	1	296.8	304.2
8	1	0	1	352.6	347.0
9	0	−1	−1	343.1	341.1
10	0	1	−1	182.7	186.5
11	0	−1	1	346.0	342.2
12	0	1	1	281.8	283.7
13	0	0	0	216.5	220.3
14	0	0	0	210.3	220.3
15	0	0	0	230.7	220.3
16	0	0	0	223.8	220.3