An extracellular and cellulase-free xylanase (EX624) was produced by Streptomyces sp. CS624 using an
agricultural residue (wheat bran) as a growth substrate. EX624 was purified from culture supernatant
using ammonium sulfate precipitation, ion exchange and gel filtration chromatography. The SDS-PAGE
and the zymogram analysis of the purified xylanase indicated molecular mass of 40 kDa. Biochemical
characterization of the purified EX624 revealed its highest activity at a temperature of 60 ◦C and pH
6.0. The xylanase was adequately stable in the pH range 4.5–10.0 and at temperatures
≤50 ◦C. EX624
displayed enhanced activity in the presence of several metal ions including Fe2+, Co2+ and Ca2+. HPLC
results showed that EX624 was not only able to hydrolyze commercially available pure beechwood xylan
to xylose, xylobiose and xylotriose, but also abundantly available lignocellulosic agricultural residues in
nature such as wheat bran to xylooligosaccharides.