Medium Components Symbol Experimental value
Low (–1) High (+1)
PHENOL (mg/L) A 200 1000
KH2PO4 (g/L) B 0.5 1.5
K2HPO4 (g/L) C 0.25 0.5
MgSO4 (g/L) D 0.5 1.5
(NH4)2SO4 (g/L) E 0.25 0.5
MnSO4 (g/L) F 0.05 0.05
FeSO4 (g/L) G 0.25 0.5
NaCl (g/L) H 0 0.5
H3BO3 I 0.01 0.01
Table 1: Levels of the variables tested in Plackett-Burman Design.