Xylan 1,4-beta-xylosidase involved in the hydrolysis of xylan, a major structural heterogeneous polysaccharide found in plant biomass representing the second most abundant polysaccharide in the biosphere, after cellulose. Hydrolysis of (1->4)-beta-D-xylans, to remove successive D-xylose residues from the non-reducing termini. Optimum pH is 4.0. Retains greater than 90 percent of its original activity between pH 2.0 and 7.0 at room temperature for 3 h. Optimum temperature 70 degrees Celsius. Remains stable up to 60 degrees Celsius for 30 min, but loses activity at 80 degrees Celsius. Glycan degradation; xylan degradation. Belongs to the glycosyl hydrolase 3 family.