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. Stable in the wide pH range of 3.0 to 7.0. Stable at temperatures of up to 45 degrees Celsius and is inactivated gradually above 45 degrees Celsius. Glycan degradation; xylan degradation. Belongs to the glycosyl hydrolase 3 family.