Five grams of the dry substrate was placed in a 250 mL Erlenmeyer flask and a
nutrient salt solution (2 mL) containing (g/L): KH2PO4, 2; NH4NO3, 5; NaCl, 1; and
MgSO4·7H2O, 1 (9,10) was added by adjusting different pH (pH 1–8). Initial moisture
content was adjusted to 50% (w/w) with distilled water