We cloned XYL1, a Scytalidium acidophilum gene encoding for an acidophilic family 11 xylanase. The XYL1p protein was expressed in Pichia pastoris using the pPICZαA expression plasmid. The secreted protein was purified by TAXI affinity column chromatography. The purified XYL1p showed an optimum activity at pH 3.2 and 56°C. The Michaelis-Menten constants were determined.