Effects of initial pH value of medium on xylanase synthesis by Trichoderma reesei

Initial pH value of medium had an important influence on xylanase synthesis by Trichoderma reesei Rut C30. The results showed that low pH value was beneficial to increasing the activity of xylanase. Among three initial pHvalues of media to induce xylanase, initial pH value 4. 0 was optimal , initial pH value 5. 0 was secondary and initial pHvalue 6. 0 was poor . When carbon source was 7 g/L and initial pH value was 4. 0, the activity of xylanase was up to32. 87 IU/ml, with the productivity and yield being 6574. 0 IU/(L. d) and 4695. 7 IU/g xylan, respectively . Furtherstudy indicated that initial pH value of medium was more beneficial to increasing β-xylosidase activity. This means theinfluence of pH on the synthesis of β-xylosidase was greater than that on the synthesis of endo-xylanase .