Factor
Code
Coding level
Uncoded
Coded
-1.68
-1
0
1
1.68
Yeast extract (g/L)
X
1
x
1
12.64
14
16
18
19.36
(NH
4
)
2
SO
4
(g/L)
X
2
x
2
31.6
35
40
45
48.4
MgSO
4
×7H
2
O (g/L)
X
3
x
3
1.76
1.9
2.1
2.3
2.44
Table 2:
Range of different factors studies in the CCD design
