Enhancement of Cellulase Activity from a New Strain of Bacillus subtilis by Medium Optimization and Analysis with Various Cellulosic Substrates

Table 2

Statistical analysis of Plackett Burman design showing coefficient values, 𝑡- and 𝑃-value for each variable.

Variable	Coefficient	t-Stat	𝑃-value	Confidence level (%)
Intercept	0.107817	15.96	.000	100
CMC (𝑋1)	0.083852	12.41	.000	100
Peptone (𝑋2)	0.020703	3.06	.01	99
Yeast Extract (𝑋3)	0.024881	3.68	.003	99.7
K2HPO4  (𝑋4)	0.005974	0.88	.394	60.6*
MgSO4⋅7H2O (𝑋5)	−0.005107	−0.76	.464	53.6*
FeSO4⋅7H2O (𝑋6)	−0.009733	−1.44	.175	82.5*
MnCl2⋅4H2O (𝑋7)	0.001163	0.17	.866	13.4*

∗Insignificant values.