Purification And Some Properties Of Xylanases And β-glucosidase From Penicillium Sp. T24-2

Penicillium sp. T24-2 is a strain which exhibited high cellulase activity and xylanase activity. After culturing the strain in liquid medium for 96h, two xylanases and oneβ-glucosidase from the fermented liquor were separated and purified.The xylanase XYN-1 was purified 3.8 folds with a specific activity of 144.2 U/mg after four step purification of (NH4)2SO4 precipitation, Sephadex G-25, DE32 and Sephadex G-200 chromatography. The xylanase XYN-2 was purified 5.4 folds with a specific activity of 202.5 U/mg after purified by (NH4)2SO4 precipitation, Sephadex G-25, Ultrafiltration and Sephadex G-50 chromatography. Theβ-glucosidase was purified 20.6 folds with a specific activity of 546.7 U/mg by (NH4)2SO4 precipitation, Sephadex G-75 chromatography and DEAE-Sepharose Fast Flow chromatography.The molecular weight of XYN-1, XYN-2 andβ-glucosidase were determined as 40.7kD, 20.7kD and 140kD respectively, by SDS-PAGE.The affection of pH and temperature on the activity of enzyme were investigated. The maximum activities were obtained at pH5.5 for XYN-1, pH4.5 for XYN-2, pH3.5 forβ-glucosidase.The optimunm reaction temperature for XYN-1 and XYN-2 were 70℃and 50℃, respectively. The optimum reaction temperature forβ-glucosidase was 70℃. The two xylanases andβ-glucosidase showed good stability in acidic condition. All the threee enzymes were stalbe below 40℃.Several chemicals on xylanases andβ-glucosidase activity have been studied. The activity of XYN-1 was stimulated by ZnSO4 and MgCl2, but inhibited by MnSO4.The activity of XYN-2 was stimulated by MnSO4, but inhibited by MgCl2.Both XYN-1 and XYN-2 are inhibited severely by SDS. The activity ofβ-glucosidase was stimulated by NiCl2 and ZnSO4, but inhibited by FeSO4, MgCl2 and MnSO4. It is amazing that SDS has no obvious negative effects on the activity ofβ-glucosidase.Penicillium sp. T24-2 could produce cellulase using unpretreated rice straw as carbon source and using urea as nitrogen source. It will greatly reduce the cost in the large amount production of cellulase and xylanase. It suggests a good application in the future production of cellulose and xylanase.