Table 3. Variables and their effects values from a quadratic regression equation results of Plackett-Burman design

Variable (Xi) Effect(Exi) Coefficienti) Sum of squares F-value p-value Confidence level (%)
Glucose -4.35 -2.17 94.55 15.11 0.0081 99.20
Sucrose 3.54 1.77 62.68 10.01 0.0195 98.05
Fructose -2.55 -1.28 32.51 5.19 0.0629 93.71
GOS1) 1.7552 0.88 15.41 2.46 0.1677 83.23
Molasses 11.99 6.00 719.52 114.95 <0.0001 99.99
Yeast extract -3.02 -1.51 45.48 7.27 0.0358 96.42
Beef extract 0.72 0.36 2.62 0.42 0.5415 45.85
Tryptone 1.02 0.51 5.17 0.83 0.3983 60.17
Peptone 2.27 1.14 25.86 4.13 0.0884 91.16
NaCl 0.99 0.49 4.89 0.78 0.4109 58.91
KH2PO4 -1.39 -0.69 9.61 1.54 0.2615 73.85
K2HPO4 0.79 0.40 3.16 0.51 0.5039 49.61
MgSO4 0.86 0.43 3.68 0.59 0.4726 52.74
KCl 1.38 0.69 9.49 1.52 0.2642 73.58
1) GOS, galacto-oligosaccharide.