Fig. 9

Effect of three factors on enzyme activity of QL-Z3. Medium Number: A 2.0 g/L lignin, pH = 11, NaNO₃; B 2.0 g/L lignin, pH = 9.5, (NH₄)₂SO₄; C 2.0 g/L lignin, pH = 8, NH₄NO₃; D 2.5 g/L lignin, pH = 11, (NH₄)₂SO₄; E 2.5 g/L lignin, pH = 8, NaNO₃; F 2.5 g/L lignin, pH = 9.5, NH₄NO₃; G 3.0 g/L lignin, pH = 8, (NH₄)₂SO₄; H 3.0 g/L lignin, pH = 11, NH₄NO₃; I 3.0 g/L lignin, pH = 9.5, NaNO₃. Each experimental group was conducted in triplicate