Expression and Characterization of Recombinant Endo-β-1,4-D-xylanases XynBTN63D from Soil Termite Abdomen in Escherichia coli BL21 (DE3)

The xynBTN63D gene sub-cloned on the plasmid shuttle vector pESC and pYHM1 in the host Escherichia coli BL21 (DE3) was successfully expressed and characterized. The xynBTN63D gene in the soluble fraction of each plasmid is expressed at induction temperatures of 25, 30, 35, 37, and 40 °C with a molecular weight of ±30 kDa. The soluble fraction of the xynBTN63D gene in both plasmids was expressed at induction temperatures of 25, 30, 35, 37, and 40°C with a molecular weight of ±30 kDa. The recombinant XynBTN63D, purified using the fast protein liquid chromatography (FPLC) method also has a molecular weight of ±30 kDa, observed using the sodium dodecyl polyacrylamide sodium electrophoresis (SDS-PAGE) method. The recombinant XynBTN63D has a temperature of 40 °C and an optimum pH of 5.5. It shows stability from 4 to 40 °C after preincubation for 1 hour with relative activity on the pCES and pMH1 plasmid of more than 50%. Recombinant XynBT63D also showed pH stability after being preincubated for 24 hours by showing relative activity of 86-100% at pH 5.0 to 6.0 for each plasmid