Skip to main content
. 2023 Aug 3;22:143. doi: 10.1186/s12934-023-02158-3

Table 2.

The coded and actual values for the tested variables

Codes Factors Levels
− 1 1
X1 pH 2 7
X2 Incubation time 7 16
X3 Peptone 0.5 10
X4 Glucose 2 10
X5 Calcium Chloride 0.1 0.4
X6 Cysteine 4 8
X7 Malt extract 4 10
X8 Fructose 4 10
X9 Sucrose 4 10
X10 Salicylic acid 2 4
X11 Sodium chloride 0.1 0.4
X12 Yeast extract 2 8
X13 Potassium dihydrogene-phosphate 0.1 0.4
X14 Sodium citrate 1 4
X15 Sodium acetate 1 4
X16 Ferric chloride 0.1 0.4
X17 Glycine 1 4
X18 Starch 2 15
X19 Copper sulphate 0.1 0.4