STREPTOMYCES P12-137 ENDOXYLANASES CHARACTERISTICS EVALUATION IN ORDER TO OBTAIN XYLO-OLIGOSACCHARIDES

Crude xylanase extracellular extract synthesized by Streptomyces P12-137 strain possesses endoxylanase activity demonstrate by HPLC analysis. The crude enzyme extract was purified 4.18 fold with ammonium sulphate precipitation followed by dialysis and which confirmed the existence a two different xylanases separated at 65% (F5) and 80% (F6) ammonium sulphate saturation. Its appeared as a two enzymes and had a specific activity of 45.44 U ·mg -1 and 36.48 U · mg -1 respectively. The optimum pH and temperature for the two fractions obtained were found to be pH 7.0, 60 0 C and pH 6.5, 60 0 C, respectively. The KM and Vmax value of the F5 fraction were 0.4742 s −1 and 0.2012 mg·mL −1 and for the F6 fraction were 0.0388 mg·mL −1 and 0.6314 s −1 . Key word: Streptomyces, endoxylanase, xylo-oligosaccharides, enzyme extract