Cloning, expression and characterization of a thermo-alkali-stable xylanase from Aspergillus oryzae LC1 in Escherichia coli BL21(DE3)

In the present investigation, cloning and overexpression of xylanase (XynF1), the main xylanase of A. oryzae LC1, was performed in prokaryotic system E. coli BL21(DE3) to produce recombinant xylanase with high titer of specific activity (1037.3 U/mg), which was 9.3-fold higher than the native strain. Further, the recombinant XynF1 of size 37 kDa was purified using Ni2+-NTA resins followed by cation exchange chromatography, which showed an 1.8-fold increase in purity with 71.4% yield. The r-XynF1 exhibited a wide range of activity at different pH (3.0-10.0) range and temperature (30-70 degrees C) with an optimum pH at 5.0 and temperature at 30 degrees C. The results from the current study, clearly demonstrate that this is an effective method to generate a recombinant enzyme with improved activity, making it useful for possible industrial applications.